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All Business Strategies Fall into 4 Categories

• Jerome Barthelemy

Some are more creative than others.

The problem with strategy frameworks is that although they can help you determine whether an opportunity is attractive or whether a given strategy is likely to work, they generally don’t help you in the task of identifying the opportunity or crafting the strategy in the first place. This article introduces a framework, built on an in-depth analysis of the creativity literature, that aims to fill that gap by providing a systematic approach to identifying potential strategies. The framework categorizes all strategies into the following four groups, from the least creative to the most creative: adapting an existing industry strategy, combining different existing industry strategies, importing strategies from other industries, and creating a brand new strategy from scratch.

The problem with strategy frameworks is that although they can help you determine whether a given opportunity is attractive or whether a particular strategy is likely to work, they generally don’t help you in the task of identifying the opportunity or crafting the strategy in the first place. As the legendary strategy expert Gary Hamel put it: “ The dirty little secret of the strategy industry is that it doesn’t have any theory of strategy creation .”

• Jérôme Barthélemy is Executive Vice-President, Dean for Post Experience Programs, Corporate Programs and Relations and Professor of Strategy and Management at ESSEC Business School. He is the author of Myths of Strategy (Kogan Page, 2023)

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Forecasting e-commerce consumer returns: a systematic literature review

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• Published: 21 May 2024

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• David Karl   ORCID: orcid.org/0000-0002-0326-5982 1  

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The substantial growth of e-commerce during the last years has led to a surge in consumer returns. Recently, research interest in consumer returns has grown steadily. The availability of vast customer data and advancements in machine learning opened up new avenues for returns forecasting. However, existing reviews predominantly took a broader perspective, focussing on reverse logistics and closed-loop supply chain management aspects. This paper addresses this gap by reviewing the state of research on returns forecasting in the realms of e-commerce. Methodologically, a systematic literature review was conducted, analyzing 25 relevant publications regarding methodology, required or employed data, significant predictors, and forecasting techniques, classifying them into several publication streams according to the papers’ main scope. Besides extending a taxonomy for machine learning in e-commerce, this review outlines avenues for future research. This comprehensive literature review contributes to several disciplines, from information systems to operations management and marketing research, and is the first to explore returns forecasting issues specifically from the e-commerce perspective.

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1 Introduction

E-commerce has witnessed substantial growth rates in recent years and continues growing by double-digit margins (National Retail Federation/Appriss Retail 2023 ). However, lenient consumer return policies have resulted in $212 Billion worth of merchandise being returned to online retailers in the U.S. in 2022, accounting for 16.5% of online sales (National Retail Federation/Appriss Retail 2023 ). While high rates of consumer returns mainly concern specific sectors and product categories, online fashion retailing is particularly affected (Diggins et al. 2016 ). Recent studies report average shipment-related return rates for fashion retailers in the 40–50% range (Difrancesco et al. 2018 ; Karl and Asdecker 2021 ). In addition to missed sales and reduced profits (Zhao et al. 2020 ), consumer returns pose operational challenges (Stock and Mulki 2009 ), including unavoidable processing costs (Asdecker 2015 ) and uncertainties regarding logistics capacities, inventory management, procurement decisions, and marketing activities. Hence, effectively managing consumer returns is an essential part of the e-commerce business model (Urbanke et al. 2015 ).

Similar to the research conducted by Abdulla et al. ( 2019 ), this work focuses on consumer returns in online retailing (e-commerce), excluding the larger body of closed-loop supply chain (CLSC) management, which encompasses product returns related to end-of-life and end-of-use scenarios involving raw material recycling or remanufacturing. In contrast to CLSC returns, retail consumer returns are typically sent or given back unused or undamaged shortly after purchase, without any quality-related defects. These returns should be reimbursed to the consumer and are intended to be resold “as new” (de Brito et al. 2005 ; Melacini et al. 2018 ; Shang et al. 2020 ).

Regarding forecasting aspects, demand forecasting is a crucial activity for successful retail management (Ge et al. 2019 ). In contrast to demand and sales, returns constitute the “supply” side of the return process (Frei et al. 2022 ). Consequently, forecasting becomes a complex task and a significant challenge in managing returns due to the inherently uncertain nature of customer decisions regarding product retention (Frei et al. 2022 ). Moreover, return forecasts are interconnected with sales forecasts and promotional activities (Govindan and Bouzon 2018 ; Tibben-Lembke and Rogers 2002 ). Hence, forecasting objectives may vary, encompassing return quantities, timing (Hachimi et al. 2018 ), and even individual return probabilities. Minimizing return forecast errors is critical to reduce and minimize reactive planning (Hess and Mayhew 1997 ). Accurate forecasts rely on (1) comprehensive data collection, e.g., regarding consumer behavior, and (2) information and communications technology (ICT) for data processing, such as big data analytics. Despite extensive research in supply chain management (SCM), Barbosa et al. ( 2018 ) noted a lack of relevant publications exploring the "returns management" process of SCM in conjunction with big data analytics. Specifically, “the topic of forecasting consumer returns has received little attention in the academic literature” (Shang et al. 2020 ). Nonetheless, precise return forecasts positively impact reverse logistics activities’ economic, environmental, and social performance, primarily concerning quantity, quality, and timing predictions (Agrawal and Singh 2020 ). Hence, forecasting returns holds significant relevance across various supply chain stages.

1.1 Previous meta-research

Hess and Mayhew ( 1997 ) emphasized the need for extensive data analysis concerning reverse flows, which forms the basis for returns forecasting. Subsequently, research on consumer returns and reverse logistics has proliferated. Thus, before collecting data and reviewing the topic of consumer returns forecasting, we first examined existing reviews and meta-studies relevant to the subject matter. To accomplish this, we referred to Web of Science, Business Source Ultimate via EBSCOhost, JSTOR and the AIS Electronic Library as primary sources of knowledge (search term: "literature review" AND "return*" AND "forecast*”). As a secondary source, we appended the results of Google Scholar, Footnote 1 for which a different search term was used (intitle:"literature review" ("product return" OR "consumer return" OR "retail return" OR "e-commerce return") forecast) due to unavailable truncations and to reduce the vast amount of literature with financial focus the search term “return” would lead to. Table 1 presents the most pertinent literature reviews related to the scope of this paper.

Agrawal et al. ( 2015 ) identified research gaps within the realm of reverse logistics, finding “forecasting product returns” as a crucial future research path. However, among 21 papers focusing on “forecasting models for product returns”, the emphasis was predominantly on CLSC, reuse, remanufacturing, and recycling, which do not align with the aim of this review. Agrawal et al. also noted a lack of comprehensive analysis of underlying factors in returns forecasting, such as demographics or consumer behavior.

Similarly, Hachimi et al. ( 2018 ) addressed forecasting challenges within the broader context of reverse logistics. They classified their literature using various forecasting approaches: time series and machine learning, operations research methods, and simulation programs. The research gaps they identified included a limited number of influencing factors taken into account, the absence of established performance indicators, and methodological issues related to dynamic lot-sizing with returns. Although this review focused on reverse logistics, the call for research into predictors of future returns is equally applicable to consumer returns in e-commerce.

The review of Abdulla et al. ( 2019 ) centers on consumer returns within the retail context, particularly in relation to return policies. While they discuss consumer behavior and planning and execution of returns, they do not present any sources explicitly focused on forecasting issues.

Micol Policarpo et al. ( 2021 ) reviewed the literature on the use of machine learning (ML) in e-commerce, encompassing common goals of e-commerce studies (e.g., purchase prediction, repurchase prediction, and product return prediction) and the ML techniques suitable for supporting these goals. Their primary contribution is a novel taxonomy of machine learning in e-commerce, covering most of the identified goals. However, within the taxonomy developed, the aspect of return predictions is disregarded.

The most exhaustive literature review to date regarding product returns, conducted by Ambilkar et al. ( 2021 ), analyzed 518 papers and adopted a holistic reverse logistics approach encompassing all supply chain stages. The authors categorized the papers into six categories, including “forecasting product returns”, for which they found and concisely described 13 papers. Due to the broader research scope, none of the analyzed papers focused on consumer returns within the retail context.

The review by Duong et al. ( 2022 ) employed a hybrid approach combining machine learning and bibliometric analysis. Regarding forecasts of product returns, they identified three relevant papers (Clottey and Benton 2014 ; Cui et al. 2020 ; Shang et al. 2020 ) within the “operations management” category. They explicitly call for further research on predicting customer returns behavior in the pre-purchase stage, highlighting the importance of a better understanding of online product reviews and customers’ online interactions.

1.2 Research gaps and research questions

Why is a systematic literature review necessary for investigating consumer returns and forecasting? On the one hand, there are empirical and conceptual papers that touch upon this topic, including brief literature reviews that align with the subject’s focus (e.g., Hofmann et al. 2020 ). However, narrative reviews lack transparency and replicability (Tranfield et al. 2003 ) and often induce selection bias (Srivastava and Srivastava 2006 ) as they tend to approach a field from a specific perspective. In contrast, systematic reviews strive to present a holistic, differentiated, and more detailed picture, incorporating the complete available literature (Uman 2011 ). On the other hand, existing systematic reviews provide structured yet relatively superficial overviews of literature on end-of-use and end-of-life forecasting (Shang et al. 2020 ), but they do not specifically address consumer returns. Furthermore, we contend that a review dedicated to general reverse logistics forecasting would not adequately capture the distinctive context and requirements inherent in the consumer-retailer relationship within the realm of e-commerce (Abdulla et al. 2019 ).

Consequently, based on existing reviews and papers, we have identified research gaps worth examining more in detail: (1) Returns forecasting techniques and relevant predictors for the respective underlying purposes, especially in the context of e-commerce (RQ1 and RQ2); (2) the integration of return forecasts into an existing but incomplete taxonomy of machine learning in e-commerce (Micol Policarpo et al. 2021 ; RQ3); and (3) future research directions pertaining to e-commerce returns forecasting (RQ4). Therefore, this review aims to shed more light on consumer returns forecasting in the retail context. The following research questions outline the primary objectives:

RQ1: What key research problems (e.g., forecasting purposes, technological approaches) have been addressed in the literature on forecasting consumer returns over time?

RQ2: What are the …

Publication outlets and research disciplines,

Research types and methodologies,

Product categories and industries,

Data sources and characteristics,

Relevant forecasting predictors,

Techniques and algorithms

… used to address these key problems?

RQ3: How can returns forecasting be integrated into a taxonomy of machine learning in e-commerce?

RQ4: What are promising or emerging future research directions regarding forecasting consumer returns?

The paper is organized as follows: Sect.  2 describes selected fundamental concepts and the delimitation of the research field on consumer returns forecasting. Section  3 contains the methodology for the review, drawing on the PRISMA guideline (Page et al. 2021 ) while integrating the approaches of Denyer and Tranfield ( 2009 ) and Webster and Watson ( 2002 ). Section  4 presents the review’s main results, answering RQs 1 (Sect.  4.1 ), RQ2 (Sects.  4.2 – 4.5 ), and RQ 3 (Sect.  4.6 ). A research framework developed in Sect.  5 structures the discussion regarding future research directions (RQ4). Section  6 subsumes the overall contribution of this review.

2 Consumer returns and forecasting

2.1 consumer returns and return reasons.

Reverse product flows, commonly referred to as product returns, can be classified into three categories: manufacturing returns, distribution returns, and consumer returns (Shaharudin et al. 2015 ; Tibben-Lembke and Rogers 2002 ). Among these, consumer returns are further differentiated between returns in brick-and-mortar retail or mail-order/e-commerce returns (Tibben-Lembke and Rogers 2002 ) and are also known as commercial returns (de Brito et al. 2005 ) or retail (product) returns (Bernon et al. 2016 ). With sky-rocketing e-commerce sales, online consumer returns have emerged as the dominant segment, making them a highly relevant field of research (Abdulla et al. 2019 ; Frei et al. 2020 ). Additionally, the digitization of retail provides numerous opportunities for data collection, as digital customer accounts facilitate more efficient analytical monitoring of customer behavior (Akter and Wamba 2016 ). Simultaneously, as competitive pressures intensify in e-commerce due to increased price transparency and substitution possibilites, retailers aiming to stimulate impulse purchases face hightened return rates (Cook and Yurchisin 2017 ; Karl et al. 2022 ).

The spatial decoupling of supply and demand introduces a higher level of uncertainty for e-commerce customers regarding various product attributes compared to bricks-and-mortar retailing (Hong and Pavlou 2014 ). As consumers are unable to physically assess the products they order, this translates into returns being essential part of the e-commerce business model. Besides fit uncertainty, other reasons for returns exist. Stöcker et al. ( 2021 ) classify the drivers triggering consumer returns into consumer behavior related reasons (e.g., impulsive purchases, showrooming), fulfillment/service related reasons (e.g., wrong/delayed delivery) and information gap related reasons (product fit, insufficient visualization). By mitigating customers’ return reasons, retailers try to reduce the return likelihood (“return avoidance”) (Rogers et al. 2002 ). Another, but less promising way of reducing returns, is preventing customers who intend to return from actually doing so (e.g., by incurring additional effort or by rejecting returns) (Rogers et al. 2002 ).

Adapted from Abdulla et al. ( 2019 ) and Vakulenko et al. ( 2019 ), a simplified parallel process of a return transaction from the consumer’s and retailer’s perspective is visualized in Fig.  1 . Retailers can use forecasting in all transaction phases (Hess and Mayhew 1997 ). Targeting customer interventions pre-purchase (real-time forecasting) could be implemented by using dynamically generated (Dalecke and Karlsen 2020 ) digital nudging elements (Kaiser 2018 ; Thaler and Sunstein 2009 ; Zahn et al. 2022 ) in case of a predicted high return propensity. In the post-purchase phase, forecasting could stimulate different interventions (e.g., customer support) or can be helpful for logistics and inventory planning activities (Hess and Mayhew 1997 ). In the phase after the return decision, data analysis, including segmentation on different levels, e.g., for customers, products, or brands (Shang et al. 2020 ), can support managerial decision-making regarding assortment or (individualized) return policies for future orders (Abdulla et al. 2019 ). In other words, forecasting (or modeling) of returns in later phases of the process can substantiate interventions in earlier phases of the process (e.g., a temporary return policy change, or the suspension of product promotions due to particular forecasts). However, such data-driven interventions itself also represent an influencing factor to be taken into account in future forecasts; thus, different forecasting purposes can be linked, at least when it comes to the data required. All these interdependencies hint at the circularity of the returns process, with an adequate management of returns representing an opportunity for generating customer satisfaction and retention (Ahsan and Rahman 2016 ; Röllecke et al. 2018 ).

Purchase and return process concerning forecasting issues (adapted from Abdulla et al. 2019 ; Vakulenko et al. 2019 )

Although primarily focussing on the online retailers’ process, it is worth noting that the issue at hand is equally applicable to brick-and-mortar retail (Santoro et al. 2019 ), which can benefit from the application of advanced data analysis techniques for forecasting purposes (Hess and Mayhew 1997 ).

2.2 Forecasting purposes and corresponding techniques

Accurate forecasting holds significant importance in the realm of e-commerce. Precise demand forecasts (“predictions”) play a pivotal role in inventory planning, pricing, and promotions and ultimately impact the commercial success of retailers (Ren et al. 2020 ). Forecasting consumer returns affects similar business aspects and resorts to comparable existing technical procedures. The data science and statistics literature offers diverse methods and algorithms for forecasting consumer returns. The choice of approach depends on the specific objective, with the outcome variable being scaled accordingly. For instance, when forecasting whether a single product will be returned, the dependent variable is either binary or expressed as a propensity value ranging form 0 to 1. On the other hand, forecasting the quantitay or timing of returns entails continuous outcome variables. As a result, various techniques, from time-series forecasting to machine learning approaches can be applied, which will be briefly outlined in the subsequent sections.

2.2.1 Return classifications and propensities

A naïve method for determining the propensity or return decision forecast is using lagged (historical) return information (return rates), either for a given product, a given customer, or any other reference, to calculate a historical return probability (Hess and Mayhew 1997 ). Return rate forecasts are a reference-specific variant of forecasting return propensities.

Simple causal models based on statistical regression methods utilize one or more independent exogenous variables. The logistic regression (logit model) is employed when the dependent variable is binary or contains more nominal outcomes (multinomial logistic regression). For each observation, the binary logistic regression assesses the probability that the dependent variable takes the value “1” (Hastie et al. 2017 ). Consequently, this approach finds application for return decisions and return propensities. Comparatively, linear discriminant analysis (Fisher 1936 ) bears a resemblance to logistic regression by generating a linear combination of independent variables to best classify available data. This classification process involves determining a score for each observation, subsequently compared to a critical discriminant score threshold, and distinguishing between return and keep.

More sophisticated machine learning (ML) techniques such as neural networks, decision tree-based methods, ensemble learning, and boosting methods are highly suitable for this forecasting purpose. For a general exposition of ML techniques in the domain of e-commerce, we refer to Micol Policarpo et al. ( 2021 ). Additionally, for a comparative study of several state-of-the-art ML classification techniques, see Fernández-Delgado et al. ( 2014 ). Artificial Neural Networks (NN) consist of interconnected nodes (“neurons”) organized in layers, exchanging signals to ascertain a function that accurately assigns input data to corresponding outputs. Typically, supervised learning techniques such as backpropagation compare the network outputs with known actual values (Hastie et al. 2017 ). Notably, neural networks are the most popular machine learning algorithm in last years’ e-commerce research (Micol Policarpo et al. 2021 ), and deep learning extensions like Long Short-Term Memory (Bandara et al. 2019 ) are gaining attention. Decision Trees (DT) manifest as hierarchical structures of branches representing conjunctions of specific characteristics and leaf nodes denoting class labels. This approach endeavors to construct an optimal decision tree for classifying available observations. Many decision tree algorithms have been introduced to serve this purpose (e.g., Breiman et al. 1984 ; Pandya and Pandya 2015 ). Ensemble learning methods adopt a voting mechanism involving multiple algorithms to enhance predictive performance (Polikar 2006 ). Analogously, boosting and bagging techniques are incorporated in algorithms like AdaBoost or the tree-based Random Forest (RF) to augment the input data, aiming at more generalizable forecasting models less prone to overfitting issues (Hastie et al. 2017 ). Support Vector Machines (SVM) stand as another example of a supervised ML algorithm, having demonstrated efficacy in tackling classification problems within e-commerce (Micol Policarpo et al. 2021 ).

2.2.2 Return timing and volume forecasts

For product returns, timing is crucial in forecasting end-of-life, end-of-use, or remanufacturing returns that can occur years after the initial purchase (Petropoulos et al. 2022 ). In contrast, for consumer returns, the possible time window in which products are regularly returned in new condition with the aim of a refund is much shorter (usually less than 100 days and mostly less than 30 days), and priorities are more on forecasting return volumes. Forecasting return volumes can be multi-faceted, ranging from forecasting the total return volume a retailer has to process within its logistics department through forecasting product-specific return numbers up to forecasting costly return shares, e.g., return fraud volume. Because returns depend on fluctuating sales, time-series forecasting of return volumes performs only well with constant sales volumes or under risk-pooling (Petropoulos et al. 2022 ). Thus, for a naïve return volume forecast, sales forecasts for a given timeframe are multiplied by the lagged return rate (historical data of products/consumers or any other reference). Possible algorithms for estimating historical return rates include time series forecasting to causal predictions comprising ML approaches (Hachimi et al. 2018 ).

Time-series techniques, e.g., single exponential smoothing (SES) or Holt-Winters-approaches (HW), are based on the assumption that the future development of an outcome variable (e.g., return volume) is dependent on its past numbers, while time acts as the only predictor. Most of these models can be generalized as autoregressive moving averages (ARIMA) models, for which numerous extensions are available. These models can approximate more complex temporal relationships. Similarly, time-series regression models use univariate linear regression with time as a single exogenous variable.

The mentioned multivariate regression models are essential statistical tools and can predict metric variables such as return volume or time. The logic is to fit a linear function of a given set of input variables (“features”) to the outcome variable with the criteria of minimizing the residual sum of squares (Hastie et al. 2017 ). Many variants of regression models are derived from this logic (e.g., generalized linear models), and various extensions are built upon this base (e.g., LASSO for variable selection, Tibshirani 1996 ).

Emerging from more complex statistical methods and using the possibilities of continuously increasing computing power, IT-based machine learning (ML) approaches were developed. Some of these approaches have already been presented in Sect. 2.2.1, being suitable for predicting metric variables in addition to classification tasks, e.g., neural networks, decision tree algorithms, and especially ensemble techniques like random forests.

3 Methodology

Methodologically, the research process of this review follows the PRISMA guideline (Page et al. 2021 ) where applicable and is structured in five steps (Denyer and Tranfield 2009 ; Webster and Watson 2002 ): (1) question formulation; (2) locating studies; (3) study selection and evaluation; (4) (concept-centric) analysis and synthesis; and (5) reporting and using the results for defining an agenda for future research.

The first step refers to the research questions already formulated in the introduction. The second step involves selecting the databases and defining the search terms. In that respect, five scientific databases were selected, aiming at journal as well as conference publications: AIS Electronic Library (AISeL), Business Source Ultimate (BS) via EbscoHost, JSTOR (JS), Science Direct (SD), and Web of Science (WoS). To ensure inclusivity and to account for potential variations in spelling or phrasing, the final search strings incorporate truncations where applicable. The search query utilized in this review comprises two key components. Firstly, it pertains to consumer returns, encompassing products returned by consumers, primarily in the context of e-commerce, to the retailer. While it is recommended to use reasonably general search terms, the term “return” alone would yield results for various stages of reverse logistics and a vast amount of financial literature. Therefore, we conducted a more specific search using the phrase “consumer return*” and the related terms “e-commerce return*”, “product return*”, “return* product”, “customer return*”, and “retail return*”. Secondly, this paper specifically focuses on forecasting (“forecast*”), which can be alternately referred to as “predict*” or “prognos*”. The combination of these terms was searched for in the Title, Abstract and Keywords fields.

The search includes results up to the middle of 2022 and resulted in 725 initial search hits (see Fig.  2 ). As this review aims to identify papers dealing with consumer returns and forecasting, the inclusion criteria for eligibility were:

The title or keywords referred to consumer returns or forecasting (in a broader sense, including data preparation). A connection to the respective subject area and applicability to the retail domain should at least be plausible.

Manuscript in English: No important study would be written and published in a language different than English.

The paper has undergone a single- or double-blind peer-review process, either as a journal publication or as a publication in peer-reviewed conference proceedings.

Research process flow diagram

In the third step, duplicates were removed, resulting in a set of 650 unique records. Subsequently, the papers underwent screening based on title, keywords, and language to determine whether they warranted further examination. This preliminary screening phase reduced the number of papers to 85. These papers’ abstracts and full texts were thoroughly reviewed to assess their relevance. This step encompasses all papers pertaining to returns forecasting for retailers or direct-selling manufacturers while excluding those focused on closed-loop supply chain management or remanufacturing, recycling, and end-of-life returns. Ultimately, a final sample of 20 publications was identified, serving as a foundation for identifying additional relevant papers (vom Brocke et al. 2009 ; Webster and Watson 2002 ) through a forward search using Google Scholar and snowballing via backward search. This process yielded an additional five papers, resulting in a total of 25 papers included for review (Table  2 ).

The fourth step comprises the analysis and synthesis of the relevant papers. Data, including bibliographic statistics, were collected in accordance with the research questions. A two-way concept-centric analysis, as described by Webster and Watson ( 2002 ), was conducted, encompassing confirmatory aspects based on the fundamentals outlined in Sect.  2 of this paper, as well as exploratory elements aimed at enriching existing categories and concepts. The objective was to comprehensively describe the relevant concepts, approaches, and dimensions discussed in the literature.

Moving on to the fifth and final step (Denyer and Tranfield 2009 ), the results are presented. Initially, the main scope of the papers included in the analysis is presented. Next, bibliographic data pertaining to the included papers are provided to offer a concise overview of the research area and its recent developments, followed by a content analysis and synthesis of the relevant literature to delve into the current state of research and highlight key findings. Finally, Sect.  5 outlines a research agenda for the domain (vom Brocke et al. 2009 ).

4 Results of the systematic review

After outlining the main scope of the relevant publications (4.1), a short bibliographic characterization (4.2) is given. Next, this section presents the results of the systematic review, focussing on the methodology and datasets used (4.3), predictors used for returns forecasting (4.4), and forecasting techniques employed (4.5). The integration of consumer returns forecasting into an existing taxonomy for e-commerce and machine learning (Micol Policarpo et al. 2021 ) summarizes and concludes the presentation of the results.

4.1 Overview and main scope of the relevant publications

Table 3 provides an overview of the forecasting purpose of the papers, the data source for the forecasting, the algorithms employed, and the predictors used in the forecasting models. The contributions of the respective papers regarding forecasting issues are summarized in the Appendix.

For identifying research streams, the publications are analyzed regarding the intention and main scope, as described in the abstract, the respective research questions, and the remainder of the papers. Most papers were assigned to an unequivocal research scope, while some contributed to two key topics (Fig.  3 ).

Classification of main scopes (n = 25; not mutually exclusive)

At first, we identified a stream of literature regarding the comparison of different forecasting models and algorithms (Asdecker and Karl 2018 ; Cui et al. 2020 ; Drechsler and Lasch 2015 ; Heilig et al. 2016 ; Hess and Mayhew 1997 ; Hofmann et al. 2020 ; Imran and Amin 2020 ). These papers use existing approaches, adapt them for individual forecasting purposes, apply models to one or more datasets, and compare and evaluate the resulting forecasting performance. One paper claims that the difference in forecasting accuracy of easily interpretable algorithms is relatively small compared to more sophisticated ML algorithms (Asdecker and Karl 2018 ). This statement is partially confirmed (Cui et al. 2020 ), as the ML algorithms show advantages over simpler models in the training data set but have lower prediction quality due to overfitting issues in the test data. Nevertheless, fine-tuned ML approaches (e.g., deep learning with TabNet) outperform simpler models and gain accuracy when correcting class imbalances during the data preparation phase (Imran and Amin 2020 ). When confronted with large class imbalances (e.g., low return rates), boosting algorithms like Gradient Boosting work well without oversampling (Hofmann et al. 2020 ). Fundamentally, ensemble models incorporating different techniques show the maximum possible accuracy (Asdecker and Karl 2018 ; Heilig et al. 2016 ). Forecasting of return timing is more erroneous than return decisions, and split-hazard-models outperform simple OLS approaches (Hess and Mayhew 1997 ). Time series prediction only works reliably when return rates do not fluctuate heavily (Drechsler and Lasch 2015 ).

The second stream we identified focuses on feature generation or selection and dataset preparation (Ahmed et al. 2016 ; Ding et al. 2016 ; Hofmann et al. 2020 ; Rezaei et al. 2021 ; Samorani et al. 2016 ; Urbanke et al. 2015 , 2017 ). Besides this central topic, some papers also compare different forecasting algorithms (Ahmed et al. 2016 ; Hofmann et al. 2020 ; Rezaei et al. 2021 ; Urbanke et al. 2015 , 2017 ). For example, random oversampling of data with large class imbalances can improve the performance of different forecasting algorithms, while models based only on sales/return history perform worse than models with more features (Hofmann et al. 2020 ). Two similar approaches are based on product, basket, and clickstream data, using different algorithms for feature extraction (Urbanke et al. 2015 , 2017 ). The first developed a Mahalanobis Feature Extraction algorithm, proving superior to other algorithms like principal component analysis or non-negative matrix factorization (Urbanke et al. 2015 ). The second develops a NeuralNet algorithm to extract interpretable features from a high-dimensional dataset, showing superior performance and giving reasonable interpretability of the most important factors (Urbanke et al. 2017 ). For the automated integration of different data sources into single flat tables and the generation of discriminating features, a rolling-path algorithm is developed, improving performance when data is imbalanced (Ahmed et al. 2016 ). Similarly, the software “Dataconda” can automatically generate and integrate relational attributes from different sources into a flat table, which is often the required prerequisite for forecasting algorithms (Samorani et al. 2016 ). A different selection approach clusters the features into groups and applies selection algorithms to the groups, aiming to select a smaller set of attributes (Rezaei et al. 2021 ). As quite an offshoot, one paper predicts a seller’s overall daily return volume dependent on his current “reputation” measured by tweets (Ding et al. 2016 ), which needs sentiment analysis to be integrated into the forecast.

A quite heterogenous research stream belongs to the development of algorithms, heuristics, and models that go beyond a straightforward adaption of existing approaches (Fu et al. 2016 ; Joshi et al. 2018 ; Li et al. 2018 ; Potdar and Rogers 2012 ; Rajasekaran and Priyadarshini 2021 ; Shang et al. 2020 ; Sweidan et al. 2020 ; Zhu et al. 2018 ). Potdar and Rogers ( 2012 ) developed a methodology for forecasting product returns based on reason codes and consumer behavior data. Fu et al. ( 2016 ) developed a conditional probability-based statistical model for predicting return propensities while revealing return reasons and outperforming some baseline benchmark models. Li et al. ( 2018 ) describe their “HyperGo” approach as a ‘framework’ and develop an algorithm for forecasting return intention after basket composition. Zhu et al. ( 2018 ) describe a “LoGraph” random walk algorithm for predicting returned customer/product combinations within their framework. Although Joshi et al. ( 2018 ) label their approach as a “framework”, they describe a specific two-stage algorithm for forecasting return decisions based on network science and ML. Rajasekaran and Priyadarshini ( 2021 ) developed a hybrid metaheuristic-based regression approach to predict return propensities.

Seven papers deal with concepts, meta-models, or substantial frameworks for returns forecasting (Fu et al. 2016 ; Fuchs and Lutz 2021 ; Heilig et al. 2016 ; Hofmann et al. 2020 ; Li et al. 2018 ; Shang et al. 2020 ; Zhu et al. 2018 ). A generic framework for a scalable cloud-based platform, which enables a vertical and horizontal adjustment of resources, could enable the practical real-time use of computationally intensive ML algorithms for forecasting returns in an e-commerce platform (Heilig et al. 2016 ). Two papers (Fuchs and Lutz 2021 ; Hofmann et al. 2020 ) are based on design science research (DSR, Hevner et al. 2004 ) for developing artifacts like meta models and frameworks. The first also refers to CRISP-DM, the “Cross Industry Standard Process for Data Mining” (Wirth and Hipp 2000 ), and develops a shopping-basket-based general forecasting approach suitable across different industries without domain knowledge and attributes needed (Hofmann et al. 2020 ). In a similar approach, based on the basket composition and user interactions, a generic model for real-time return prediction and intervention is developed (Fuchs and Lutz 2021 ) and prepared for integration into an ERP system. Fu et al. ( 2016 ) present a generalized return propensity latent model framework by decomposing returns into different inconsistencies (unmet product expectations, shipping issues, and both factors combined) and enriching the derived propensities with product features and customer profiles. Li et al. ( 2018 ) developed a “HyperGo” framework for forecasting the return intention in real-time after basket composition, including a hypergraph representation of historical purchase and return information. Similarly, Zhu et al. ( 2018 ) developed a “HyGraph” representation of historical customer behavior and customer/product similarity, combined with a “LoGraph” random-walk-based algorithm for predicting customer/product combinations that will be returned. Shang et al. ( 2020 ) discuss two opposing forecasting concepts, demonstrating that their predict-aggregate framework is superior to common and more naïve aggregate-predict approaches.

The last stream covers the detection and forecasting of return fraud and abuse (Drechsler and Lasch 2015 ; John et al. 2020 ; Ketzenberg et al. 2020 ; Li et al. 2019 ). On the employees’ side, one paper tries to automatically predict fraudulent return behavior of agents (employees), e.g., regarding unjustified refunds, by a penalized logit model, enabling a lift in detection (John et al. 2020 ). On the customers’ side, misused returns as a cost-incurring problem are the forecasting purpose of different time series prediction models (Drechsler and Lasch 2015 ). Instead of focussing on fraudulent transactions, a trust-aware random walk model identifies consumer anomalies, enabling retailers to apply targeted measures to specific customer groups (selfish, honest, fraud, and irrelevant customers) (Li et al. 2019 ). Similarly, returning customers can be categorized into abusive, legitimate, and nonreturners (Ketzenberg et al. 2020 ). Based on the characterization of abusive return behavior, a neural network classifier recaptures almost 50% of lost profits due to return abuse (Ketzenberg et al. 2020 ).

One paper (Sweidan et al. 2020 ) could not be assigned to the other scopes. It applies a single algorithm (RF) to a given dataset, and it contributes to the idea that only forecasted return decisions with high confidence should be used for targeted interventions due to their overproportional reliability.

4.2 Bibliographic literature analysis

Forecasting consumer returns has gained more research attention since 2016 (Fig.  4 ). The majority of the sample are conference publications, a couple of years ahead of the rise in journal publications. Compared to the publications on returns forecasting in the broader context of reverse logistics, which emerged in 2006 (Agrawal et al. 2015 ), the research on consumer returns moved into the spotlight about ten years later. This development is linked to a massive increase in e-commerce sales pre- and in-pandemic (Alfonso et al. 2021 ).

Publication trend by publication outlet

Out of 9 journal publications in the final sample, only two are published in the same journal (Journal of Operations Management). Out of 16 conference papers, 6 are published at conferences of the Association for Information Systems. In total, 16 of the 25 papers found are published in Information Systems (IS) and related outlets. Others can be assigned to the Management Science / Operations Research discipline (3), Strategy & Management in a broader sense (4), Marketing (1), and Research Methods (1) (Fig.  5 ).

Distribution of publication disciplines

Regarding the researchers’ geographical perspective, one paper was jointly published by authors from the US and China, 10 of 25 papers were authored from North America, followed by authors from Germany (7), India (3), China (1), and one paper each from Bangladesh, Singapore, and Sweden.

The most cited paper (200 external citations Footnote 2 ) from Hess and Mayhew ( 1997 ) could be thought of as the root of this research field (Table  4 ). However, only 10 out of 24 papers reference this work. Although Urbanke et al. ( 2015 ) received only 15 citations in total, within the sample, it is the second most cited paper (8 citations) and could eventually be classified as a research strand and origin of returns forecasting in the IS domain. Concerning the remaining papers, no unique strands of literature are recognizable based on citation analysis.

4.3 Methodology and data characterization

Regarding methodology, most of the papers start with a short narrative literature review regarding their respective focus. Not a single paper was based on interviews, surveys, questionnaires, or field experiments. 3 out of 25 papers formulated and tested conventional hypotheses. All of the publications use quantitative data for analysis and forecasting in a “case study” style, including numerical experiments based on real or simulated data.

Table 5 lists further details about the data used in the publications. 4 out of 25 papers rely on simulated data, and 23 out of 25 integrate actual data gained from a retailer. Two papers use both data types. 5 papers use more than one dataset (Ahmed et al. 2016 ; Cui et al. 2020 ; Rezaei et al. 2021 ; Samorani et al. 2016 ; Shang et al. 2020 ). The most frequently studied industry is fashion/apparel (10 papers), followed by five consumer electronics datasets. Two publications are based on data from a Taobao cosmetics retailer, and two datasets originate from general and wide assortment retailers. Two datasets incorporate building material and hardware store articles, and the detailed products are not named for three publications. Based on the previous studies, it is evident that consumer returns forecasting is most relevant for e-commerce, as 19 of the 25 publications refer to e-tailers. Nevertheless, 7 publications refer to brick-and-mortar retailing. Direct selling/marketing is represented in 2 data sets.

4.4 Predictors for consumer returns

There is an individual stream of research into factors that influence or help avoid consumer returns (e.g., Asdecker et al. 2017 ; De et al. 2013 ; Walsh and Möhring 2017 ), which is not part of this review. Nevertheless, the forecasting literature gives insights into return drivers, as the input variables (features, predictors, exogenous variables) for forecasting models represent some of these factors. Table 6 presents the most used predictors and tries to map these to the return driver categorization from Sect.  2.2 (Stöcker et al. 2021 ).

Although only a part of the publications interprets the predictors, some insights can be extracted. For total return volume , sales volume is the most critical predictor (Cui et al. 2020 ; Shang et al. 2020 ). Historical return volume trends can include behavioral aspects (e.g., impulse purchases) in a given timeframe (Cui et al. 2020 ; Shang et al. 2020 ). The product type significantly impacts the volume of returns (Cui et al. 2020 ), confirmed by widely varying return rates between different industries/sectors. Adding transaction-, customer-, or product-level predictors led to a surprisingly small forecasting accuracy gain (4% reduction of RMSE, Shang et al. 2020 ). The latter input variables may be more critical in forecasting return decisions and propensities.

Regarding product attributes , product or order price is one of the most common predictors, while some papers also include price discounts. In most models, price is hypothesized to increase returns (e.g., Asdecker and Karl 2018 ; Hess and Mayhew 1997 ). Promotional (discounted) orders also seem to result in more returns (Imran and Amin 2020 ), which could be explained by the stimulation of impulse purchases. Footnote 3 Brand perception influences return decisions (positive brands, lower returns) (Samorani et al. 2016 ). The order and return history of products are also relevant for predicting future orders and returns (Hofmann et al. 2020 ). Fit importance as a product attribute does not significantly change return propensities (Hess and Mayhew 1997 ).

Concerning customer attributes , gender seems essential, as female customers return significantly more items than men (Asdecker and Karl 2018 ; Fu et al. 2016 ). Younger customers show a slightly lower propensity to return (Asdecker and Karl 2018 ), but age played a more prominent role in predicting return fraud among employees than in customers (John et al. 2020 observed more fraud among younger employees). Customers with low credit scores returned more (Fu et al. 2016 ). The return history of a customer is possibly the most important predictor of future return behavior (Samorani et al. 2016 ). Some papers argue that consumer attributes, including purchase and return history (e.g., number and value of orders), are more relevant predictors than product or transaction profiles, reflecting more or less stable consumer preferences (Li et al. 2019 ).

Basket interactions are significant (Urbanke et al. 2017 ) in returns prediction. E.g., the larger the basket, the higher the return propensity will be (Asdecker and Karl 2018 ). Selection orders (same product in different sizes or colors) increase the return propensity (Li et al. 2018 ). Logistics attributes like delivery times only show minor effects (Asdecker and Karl 2018 ). Regarding the payment method, prepaid products are sent back less frequently than those with post-delivery payment options (Imran and Amin 2020 ), confirming other research results (Asdecker et al. 2017 ).

One literature stream focuses on the automated generation of features , as different and large-scale data sources need to be integrated and prepared for forecasting algorithms. Thus, possible interrelationships are complex to find manually, and ML approaches might outperform human analysts (Rezaei et al. 2021 ). While some approaches generate a large number of features that are hard to make sense of (Ahmed et al. 2016 ), the approach of Urbanke et al. ( 2017 ) aims to maintain the interpretability of automatically generated input variables. Some unexpected but meaningful interrelations might be found by automatic feature generation, e.g., the price of the last returned orders (Samorani et al. 2016 ). Nevertheless, automatic feature generation might be computation-intensive; thus, a parallel integration of feature selection could be advantageous for large data sets (Rezaei et al. 2021 ).

A remarkable research path based on artificial intelligence is integrating qualitative information like product reviews as predictors, going beyond numerical feedback (Rajasekaran and Priyadarshini 2021 ) or tweets. These data can be processed and made accessible for forecasting with ML-based sentiment analysis techniques (Ding et al. 2016 ).

4.5 Forecasting techniques and algorithms

To describe the techniques and algorithms employed, we sorted the papers by forecasting purpose as described in Sect.  2 , then assigned them to different algorithms, either from time series forecasting, statistical techniques, or ML algorithms. Table 7 lists all papers for which an assignment was possible, and the respective techniques used. If a comparison was possible, the best-performing algorithm is marked in this table.

The approaches listed in Table  7 are overlap-free, but some papers use more than one version of an approach, i.e., more than one algorithm from a category. E.g., TabNet is a DeepLearning version of neural networks (NN), and different variants of GradientBoosting are compared in one paper (CatBoost/LightGBM, not differentiated in the table below) (Imran and Amin 2020 ).

The algorithm used most frequently (Fig.  6 ) is the Random Forest algorithm (RF, 10 papers), followed by Support Vector Machines (SVM, 8 papers), Neural Networks (NN, 6 papers), logistic regression (Logit, 6 papers), GradientBoosting (5 papers), Ordinary Least Squares regression (OLS, 4 papers), Adaptive Boosting (AdaBoost), Linear Discriminant Analysis (LDA), and CART (Classification and Regression Trees, 3 papers each).

Most frequently used algorithms (used in at least three papers)

The papers focusing on return volume use time series forecasts like (AutoRegressive) Moving Averages (MA), Single Exponential Smoothing (SES), and Holt-Winters Smoothing (HWS) more frequently than ML algorithms. Nevertheless, when considering a predict-aggregate approach as proposed by Shang et al. ( 2020 ), these ML techniques could be helpful in forecasting return decisions first and cumulating the propensity results for the volume prediction in the second step.

In forecasting binary return decisions, Random Forests (RF) (Ahmed et al. 2016 ; Heilig et al. 2016 ; Ketzenberg et al. 2020 ), Neural Networks (NN) (Imran and Amin 2020 ; Ketzenberg et al. 2020 ), as well as Adaptive Boosting (AdaBoost) (Urbanke et al. 2015 , 2017 ) showed high prediction performance. The performance of different algorithms varies depending on the data set, the implementation, and the parameterization used. For this reason, it is hardly possible to make a generally valid statement regarding performance levels. Combining several algorithms in ensembles (Asdecker and Karl 2018 ; Heilig et al. 2016 ) seems advantageous, at least for retrospective analytical purposes, when the required computing resources are less relevant.

When evaluating different forecasting algorithms for return decisions, imbalanced classes (especially evident for low return shares in non-fashion datasets) seem to be handled differently depending on the algorithms. Class imbalances might distort comparison results in some publications. Random oversampling as a measure of data preparation can solve this problem (Hofmann et al. 2020 ).

High-performance algorithms are needed for real-time predictions, e.g., graph and random-walk-based (Li et al. 2018 ; Zhu et al. 2018 ). According to Li et al. ( 2018 ), the proposed algorithm “HyperGo” performs best for most performance metrics.

4.6 E-Commerce and machine learning taxonomy extension

In their literature review regarding the use of ML techniques in e-commerce, Micol Policarpo et al. ( 2021 ) propose a taxonomy to visualize specific ML algorithms in the context of e-commerce platforms. This novel kind of taxonomy is based on direct acyclic graphs, i.e., all input variables need to be fulfilled to reach the target. The first level of the taxonomy represents different target goals for the use of ML in e-commerce. While returns forecasting (“product return prediction”) is identified as an essential goal among others (purchase prediction, repurchase prediction, customer relationship management, discovering relationships between data, fraud detection, and recommendation systems), it was excluded from the taxonomy they developed, possibly because the review comprised only two relevant papers on this topic (Micol Policarpo et al. 2021 ). The review at hand proposes an extension of Micol Policarpo’s taxonomy, renaming the goal to “consumer returns forecasting”. This extension reflects and synthesizes the consumer returns forecasting studies reviewed.

The middle level of the taxonomy represents properties and features that support this superordinate goal. On this level, our extension does not include return fraud detection, which we propose to be integrated into the existing category of “fraud detection”, separated into transaction analysis and consumer analysis (Micol Policarpo et al. 2021 ). Circles represent the necessary data to execute the analysis, referring to categories introduced in (Micol Policarpo et al. 2021 ), with an additional “return history” category. The bottom level presents the algorithms described frequently, while some streamlining is required regarding the tools and approaches that seem the most common or most appropriate.

The schematic above (Fig.  7 ) is to be read as follows: In the context of E-Commerce  +  Artificial Intelligence (Layer 1), Consumer Return Forecasting (Layer 2) is an essential goal among six other goals. Layer 3 presents different purposes of analysis, which are the base for return forecasting. Realtime Basket Analysis is based on clickstream data and basket composition (browsing activities) to target interventions. Basket analysis benefits from customer and product information (dotted line). Graph-based approaches (Li et al. 2018 ; Zhu et al. 2018 ) are promising for real-time analysis due to their lower computing requirements, although cloud-based implementation of more complex algorithms or ensemble models might be feasible (Fuchs and Lutz 2021 ; Heilig et al. 2016 ; Hofmann et al. 2020 ). Customer Analysis and Product Analysis (e.g., Potdar and Rogers 2012 ) require adequate Data Preparation in the sense of input variable generation, extraction, and selection (Urbanke et al. 2015 , 2017 ). For these purposes, data regarding return history (e.g., Hofmann et al. 2020 ; Ketzenberg et al. 2020 ), purchase history (e.g., Cui et al. 2020 ; Fu et al. 2016 ), customer personal information (e.g., Heilig et al. 2016 ; Ketzenberg et al. 2020 ), clickstream data, and browsing activities are required as input (shown by cross-hatched circles). For each purpose, one or more possible algorithms are shown.

Proposed consumer returns forecasting extension to the E-commerce and Machine Learning techniques taxonomy of Micol Policarpo et al. ( 2021 , p. 13)

Compared to predicting purchase intention, return predictions seem to require more levels of data. Nevertheless, even simple rule-based interventions can promise benefits, e.g., selection orders that inevitably lead to a return shipment can be easily recognized (Hofmann et al. 2020 ; Sweidan et al. 2020 ). Different ML techniques are helpful for data preparation and input variable (feature) extraction and generation when considering more complex interrelations. NeuralNet is one example of an automatic selection of relevant features (Urbanke et al. 2017 ). These approaches are not only able to enhance forecasting accuracy (Rezaei et al. 2021 ) but can also render the many possible variables interpretable about their content.

5 Discussion

The analysis of the papers above revealed that research in this discipline seems heterogeneous and partly fragmented, and clear-cut research strands are still hard to identify. Thus, the existing literature calls for further publications to render this research field more comprehensive. Below, research opportunities are derived and embedded in a conceptual research framework derived from the results of the existing literature, also integrating the extension of the E-Commerce and Machine Learning taxonomy (Fig.  7 ). A conceptual framework improves the understanding of a complex topic by naming and explaining key concepts and their relationships important to a specific field (Jabareen 2009 ; Miles et al. 2020 ). Thus, this framework aims to organize problems and solutions discussed in the consumer returns forecasting literature and to embed and classify potential future research topics in the existing knowledge base (Ravitch and Riggan 2017 ). The subsections following the framework outline some potential research avenues (P1–P6) that have been touched on in the past but still leave considerable opportunities for further insights. These proposals should not be seen as comprehensive due to numerous other research opportunities in this field but rather as prioritization based on the current literature.

The framework derived (Fig.  8 ) underlines the interdisciplinary nature of this research field, integrating different perspectives (information systems research, marketing and operations perspective, and strategy and management perspective). From a managerial point of view, the literature included in this review is biased towards the information systems perspective. Thus, in contrast to the framework developed by Cirqueira et al. ( 2020 ) for purchase prediction, we do not take a process perspective but instead emphasize the interdependencies and interactions between research topics and highlight the managerial need to take a strategical perspective similar to the framework developed by Winklhofer et al. ( 1996 ). Consequently, a meta-layer on forecasting frameworks and practices includes the mainly technical development frameworks in this review but also accentuates the need for further research regarding actual organizational forecasting practices (e.g., P2, P5, P6). Around this meta-layer, some related research strands are linked in order to embed the topic of returns forecasting in the research landscape. E.g., in general, forecasting purchases and returns could be linked (P6), also effecting inventory decisions.

Conceptual Consumer Return Forecasting Framework

The center of the framework consists of three dimensions, namely purposes and tasks, predictors, and techniques. Depending on the strategical purpose, tasks are derived that determine (1) the data (predictors) needed and (2) the usable techniques to execute the forecasting. Different forecasting techniques require an individual set of predictors, whereas the availability of specific data allows and determines the use of more or less sophisticated algorithms.

In the literature, some forecasting purposes were more pronounced (return decisions or propensities), while others have gained less attention (return timing, P1). Regarding the data necessary for accurate forecasting, the return predictors discussed often were hardly comparable, as they originated from different data sources, different industries, were related to different dimensions, or were aggregated in another way. Systematically linking forecasting predictors and research on return drivers and reasons could contribute significant insights (P4) that, from a marketing perspective, may support the development of effective preventive instruments. Furthermore, the literature mainly refers to the fashion or consumer electronics industry, leaving room to validate the findings in the context of other industries (P3).

When (automatically) selecting or creating predictors, the boundaries between predictors and prediction techniques are blurred as machine learning algorithms prepare the input data before executing a forecasting model. Regarding forecasting techniques, time series forecasting was seldom used in recent publications. Machine learning algorithms were the most popular subject of investigation, with random forests, support vector machines, and neural networks as the most popular implementations. Classical statistical models like logit models for return decisions or OLS regression gained less research attention. Literature on end-of-life return forecasting could complement the research on techniques and their accuracy. Most publications used technical indicators for assessing the accuracy of forecasting models, which is the information systems perspective. From a managerial position, evaluating (monetary) performance outcomes (e.g., Ketzenberg et al. 2020 ) of forecasting systems should be more relevant.

5.1 Research proposal P1: return timing for consumer returns

Toktay et al. ( 2004 ) encouraged the integrated forecasting of the return rate and the return time lag. In line with this, Shang et al. ( 2020 ) criticize the missing focus on the timing of return forecasts. The reviewed literature confirms that forecasting return propensities and decisions are more prominent than timing and volume forecasts. While the knowledge of when a return is expected is vital in managing end-of-life returns that occur over the years, for retail consumer returns, return periods are mostly 14–30 days. Thus, the variability of return timing seems limited compared to end-of-life returns in this context, which makes this forecasting purpose less critical. Nevertheless, some retailers offer up to 100 days of free returns (e.g., Zalando). Consequently, more studies about the importance of return timing forecasts in the e-commerce context from a business and planning perspective and their interdependence with return processing or warehousing issues could shed light on this topic and complement the current literature (Toktay et al. 2004 ; Shang et al. 2020 ).

5.2 Research proposal P2: realtime forecasting systems

Another research gap became apparent regarding the real-time use of forecasting systems and the associated activities and interventions, building on the initial research and the frameworks already published (e.g., Heilig et al. 2016 ; Urbanke et al. 2015 ). The generic framework developed by Fuchs and Lutz ( 2021 ) could serve as a launching pad for this stream of research.

The paper from Ketzenberg et al. ( 2020 ) could act as a stimulus and inspiration for a similar approach, not only focusing on return abuse as already examined but on return forecasting in general, the possible associated interventions for various consumer groups, and the resulting consequences for the retailer’s profit. Even the methodology of customer classification could be helpful for many retailers in targeting interventions.

Before real-time return forecasting is implemented, associated preventive return management instruments need to be designed and evaluated. Many of these measures are discussed (e.g., Urbanke et al. 2015 ; Walsh et al.  2014 ), but an overview of which preventive measures (for some examples, see Walsh and Möhring 2017 ) are effective in general (1) and how forecasting accuracy interdepends with their usefulness (2) is still missing, to substantially link the topics of forecasting and interventions. No answers could be found to the call by Urbanke et al. ( 2015 ) for field experiments to investigate such a link.

Thanks to cloud and parallelization technologies and the associated scalability of computing power (Bekkerman et al. 2011 ), algorithm runtimes are becoming less relevant. However, especially for real-time use, it should be evaluated which algorithms and underlying datasets exhibit an appropriate relationship between the targeted forecasting accuracy, the expected benefit, and the required computing power.

Recommendations concerning the algorithms and techniques can be derived (Urbanke et al. 2015 ), and a generic implementation framework was developed (Fuchs and Lutz 2021 ). However, from a business perspective, no contributions could be found regarding the actual implementation of real-time forecasting systems, the interventions involved, and their impact on consumer behavior or profit (also see proposal P5). In addition, the implementations of such systems need to be analyzed concerning the cost-effectiveness of the required investments.

5.3 Research proposal P3: cross-industry and multiple dataset studies

Many publications rely on a single data set from a specific industry or retailer. Only a few compare several retailers (e.g., Cui et al. 2020 ). Studies including and comparing different countries are missing, which is especially interesting since legal regulations for returns vary. For example, in contrast to the U.S., citizens within the EU are granted a 14-day right of withdrawal for distance selling purchases. Footnote 4 Although in most developed countries, liberal and broadly comparable returns policies are standard in practice due to competitive pressure, the generalizability of the results is frequently limited. One remedy for this problem is to use multiple data sets from different retailers (e.g., electronics vs. jewelry, Shang et al. 2020 ). Admittedly, it is challenging to simultaneously collaborate with several retailers and to combine different data sets, due to reasons of preserving corporate privacy and synchronizing various data sources. Nevertheless, research needs to draw conclusions from single data points, as well as logically replicate or falsify those results by integrating more data points to find patterns of similarities and differences, either within or cross-study (Hamermesh 2007 ). Therefore, we suggest that future studies acquire industry-related datasets from several retailers at once or replicate existing studies, which aligns with the aim and scope of Management Review Quarterly (Block and Kuckertz 2018 ). Cross-industry or cross-country manuscripts, which go beyond the mere assertion of an industry-agnostic approach (Hofmann et al. 2020 ) and jointly investigate data from several sectors, would promise an additional gain in knowledge and could be less challenging from a privacy perspective.

5.4 Research proposal P4: extended study of relevant predictors in forecasting applications

Although not the main focus of this review, predictors of consumer returns are especially interesting for marketing and e-commerce research, for example, regarding preventive measures for avoiding returns. In the past, many consumer return papers highlighted single aspects or a limited selection of return drivers or preventive measures employed but rarely attempted to model return behavior as comprehensively as possible. However, the latter is the very objective of returns forecasting, which is why the findings on influencing factors in articles with a forecasting focus tend to be more holistic, although not sufficiently complete (Hachimi et al. 2018 ). Some return reasons named in the literature (e.g., Stöcker et al. 2021 ) have not yet been included in forecasting approaches, and vice versa, only a part of the influencing factors investigated could be mapped to a return reason categorization. The reason categories assigned (Sect.  4.4 , Table  6 ) still contain some uncertainty. For example, a customer’s product return history may reflect the general returning behavior of a customer to some extent, while it can not be ruled out that repeated logistical problems caused the returns. Product attributes may reflect information gaps that consumers can only assess after physically inspecting the product, whereas product price–frequently cited and influential product attribute—is only related to information gaps when considering the price-performance ratio (Stöcker et al. 2021 ). Technical information about the web browser or device used by the customer is difficult to categorize, as it may reflect behavioral (impulse-driven mobile shopping) as well as informational (small display with few visible information) aspects. The payment method chosen by a customer, for example, could not be linked to one of the reason categories.

This reasoning should serve as a basis for linking forecasting predictors and return reasons more closely in the future. For example, the respective relative weighting of return drivers is more likely to be obtained considering as many factors involved as possible, minimizing the unexplained variation. From the reviewed literature, we extracted 18 different return predictor categories. For instance, seven papers (Cui et al. 2020 ; Fu et al. 2016 ; Ketzenberg et al. 2020 ; Li et al. 2018 , 2019 ; Urbanke et al. 2015 , 2017 ) integrated more than five predictor categories. But even though some papers integrate more than 5,000 features for automated feature selection (Ketzenberg et al. 2020 ), there are still combinations of input variable categories that have not been investigated and, more importantly, interpreted yet. Therefore, we call for more comprehensive research on return predictors and their interpretation, including associated preventive return measures, in the context of return forecasting.

5.5 Research proposal P5: descriptive case studies and business implementations surveys

This review identified a lack of publications regarding the actual benefit and the diffusion of consumer returns forecasting systems in different scopes and industries, building on the papers presenting return forecasting frameworks. In 2013, less than half of German retailers analyzed the likelihood of returns (Pur et al. 2013 ). Most of those who did were using naïve approaches that might be outperformed by the models presented in this review. Still, we do not know the status quo regarding the degree of adoption and implementation of forecasting systems for consumer returns in e-commerce firms (e.g., see Mentzer and Kahn 1995 for sales forecasting systems), country-specific and internationally.

Furthermore, the impact of return forecasting practices on company performance should be examined not only based on modeling, but on retrospective data (e.g., see Zotteri and Kalchschmidt 2007 for a similar study on demand forecasting practices in manufacturing). A possible hypothesis to examine might be that accuracy measures like RMSE or precision/recall and subsequently even the choice of the most accurate machine learning algorithm (e.g., see Asdecker and Karl 2018 ) are less relevant from a business perspective: (1) No algorithm clearly outperforms all other algorithms, and (2) the correlation between technical indicators and business value is unstable (Leitch and Tanner 1991 ). Methodologically, implementations of consumer returns forecasting in e-commerce should thus be surveyed and analyzed with multivariate statistical methods to examine critical factors and circumstances of return forecasting systems – similar to publications on reverse logistics performance (Agrawal and Singh 2020 ).

5.6 Research proposal P6: holistic forward and backward forecasting framework for e-tailers

Some publications present frameworks for forecasting returns (Fuchs and Lutz 2021 ). Nevertheless, in the past, forecasting in retail and especially e-commerce commonly focused more on demand (Micol Policarpo et al. 2021 ) than returns. Current approaches for demand forecasting try to predict individual purchase intentions based on click-stream data, online session attributes, and customer history (e.g., Esmeli et al. 2021 ). Our systematic approach could not identify any paper that connects and integrates both directions in e-commerce forecasting, neither conceptual (frameworks) nor with a quantitative or case-study-like approach. Nevertheless, first implementations of return predictions in inventory management are presented (e.g., Goedhart et al. 2023 ). Subsequently, similar to Goltsos et al. ( 2019 ), we call for research addressing both demand and return uncertainties by providing a holistic forecasting framework in the context of e-commerce.

6 Conclusion

To date, no systematic literature review has undertaken an in-depth exploration of the topic of forecasting consumer returns in the e-commerce context. Previous reviews have primarily focused on product returns forecasting within the broader context of reverse logistics or closed-loop supply chain management (Agrawal et al. 2015 ; Ambilkar et al. 2021 ; Hachimi et al. 2018 ). Regrettably, the interdisciplinary nature of this subject has often been overlooked, also neglecting the inclusion of results from information systems research.

The review first aims to provide an overview of the existing literature (Kraus et al. 2022 ) on forecasting consumer returns. The findings confirm that this once novel topic has significantly evolved in recent years. Consequently, this review is timely in examining current gaps and establishing a robust foundation for future research, which forms a second goal of systematic reviews (Kraus et al. 2022 ). The current body of work encompasses various aspects from different domains, including marketing, operations management/research, and information systems research, highlighting the interdisciplinary nature of e-commerce analytics and research. As a result, future studies can find suitable publication outlets in domain-specific as well as methodologically oriented journals and conferences.

Scientifically, the algorithms and predictors investigated in previous research serve as a foundational reference for subsequent publications and informed decisions regarding research design, ensuring that specific predictors and techniques are not overlooked. Researchers can utilize this review and the research framework developed as a structuring guide, e.g., regarding relevant publications on already examined algorithms or predictors.

Managerially, the extended taxonomy for machine learning in e-commerce (Micol Policarpo et al. 2021 ) can serve as a guideline for implementing forecasting systems for consumer returns. This review classifies possible prediction purposes, allowing businesses to apply them based on their respective challenges. Exploring the most frequently used predictors reveals the data that must be collected for the respective purposes. This review also offers valuable insights into data (pre-)processing and highlights popular algorithms. Furthermore, frameworks are outlined that support the design and implementation phase of such forecasting systems, supporting analytical purposes or enabling direct interventions during the online shopping process flow. As an exemplary and promising application, return policies could be personalized (Abbey et al. 2018 ) by identifying opportunistic or fraudulent basket compositions or high-returning customers, thereby reducing unwanted returns (Lantz and Hjort 2013 ).

Finally, a limitation of this review is the exclusion of forecasting algorithms for end-of-use returns, which could potentially be applicable to forecasting shorter-term retail consumer returns. However, the closed-loop supply chain and reverse logistics literature has been systematically excluded. Hence, future reviews could synthesize previous reviews on reverse logistics forecasting with the more detailed findings presented in this paper.

The use of Google Scholar for systematic scientific information search is controversely discussed (e.g., Halevi et al. 2017 ) due to the missing quality control and indexing guidelines, as well as limited advanced search options. But as an additional database for an initial search, the wide coverage of this search system can enrich the results.

External citations according to Google Scholar, which is preferable for citation tracking over controlled databases (Halevi et al. 2017 ).

Other literature also describes a counteracting effect of a reduced price due to lowered quality expectations or a higher perceived value of the “deal” itself (e.g., Sahoo et al. 2018 ).

It should be noted that the relevance of the forecasting topic depends on the maturity of the e-commerce sector. In most developing countries, B2C e-commerce is comparatively young and consumer returns are not yet a common phenomenon, which is why research on return forecasts is relatively insignificant for these countries.

References

Abbey JD, Ketzenberg ME, Metters R (2018) A more profitable approach to product returns. MIT Sloan Manag Rev 60(1):71–74

Google Scholar  

Abdulla H, Ketzenberg ME, Abbey JD (2019) Taking stock of consumer returns: a review and classification of the literature. J Oper Manag 65(6):560–605. https://doi.org/10.1002/joom.1047

Article   Google Scholar  

Agrawal S, Singh RK (2020) Forecasting product returns and reverse logistics performance: structural equation modelling. MEQ 31(5):1223–1237. https://doi.org/10.1108/MEQ-05-2019-0109

Agrawal S, Singh RK, Murtaza Q (2015) A literature review and perspectives in reverse logistics. Resour Conserv Recycl 97:76–92. https://doi.org/10.1016/j.resconrec.2015.02.009

Ahmed F, Samorani M, Bellinger C, Zaiane OR (2016) Advantage of integration in big data: feature generation in multi-relational databases for imbalanced learning. In: Proceedings of the 4th IEEE international conference on big data, pp 532–539. https://doi.org/10.1109/BigData.2016.7840644

Ahsan K, Rahman S (2016) An investigation into critical service determinants of customer to business (C2B) type product returns in retail firms. Int Jnl Phys Dist Log Manage 46(6/7):606–633. https://doi.org/10.1108/IJPDLM-09-2015-0235

Akter S, Wamba SF (2016) Big data analytics in e-commerce: a systematic review and agenda for future research. Electron Markets 26(2):173–194. https://doi.org/10.1007/s12525-016-0219-0

Alfonso V, Boar C, Frost J, Gambacorta L, Liu J (2021) E-commerce in the pandemic and beyond. BIS Bulletin 36

Ambilkar P, Dohale V, Gunasekaran A, Bilolikar V (2021) Product returns management: a comprehensive review and future research agenda. Int J Prod Res. https://doi.org/10.1080/00207543.2021.1933645

Asdecker B (2015) Returning mail-order goods: analyzing the relationship between the rate of returns and the associated costs. Logist Res 8(1):1–12. https://doi.org/10.1007/s12159-015-0124-5

Asdecker B, Karl D (2018) Big data analytics in returns management–are complex techniques necessary to forecast consumer returns properly? In: Proceedings of the 2nd international conference on advanced research methods and analytics, Valencia, pp 39–46. https://doi.org/10.4995/CARMA2018.2018.8303

Asdecker B, Karl D, Sucky E (2017) Examining drivers of consumer returns in e-tailing with real shop data. In: Proceedings of the 50th Hawaii international conference on system sciences (HICSS). https://doi.org/10.24251/HICSS.2017.507

Bandara K, Shi P, Bergmeir C, Hewamalage H, Tran Q, Seaman B (2019) Sales Demand forecast in e-commerce using a long short-term memory neural network methodology. In: Gedeon T, Wong KW, Lee M (eds) Neural information processing: proceedings of the 26th international conference on neural information processing, 1st edn., vol 11955, pp 462–474. https://doi.org/10.1007/978-3-030-36718-3_39

Barbosa MW, La Vicente AdC, Ladeira MB, de Oliveira MPV (2018) Managing supply chain resources with big data analytics: a systematic review. Int J Log Res Appl 21(3):177–200. https://doi.org/10.1080/13675567.2017.1369501

Bekkerman R, Bilenko M, Langford J (2011) Scaling up machine learning. In: Proceedings of the 17th ACM SIGKDD international conference tutorials, p 1. https://doi.org/10.1145/2107736.2107740

Bernon M, Cullen J, Gorst J (2016) Online retail returns management. Int J Phys Distrib Logist Manag 46(6/7):584–605. https://doi.org/10.1108/IJPDLM-01-2015-0010

Block J, Kuckertz A (2018) Seven principles of effective replication studies: strengthening the evidence base of management research. Manag Rev Q 68(4):355–359. https://doi.org/10.1007/s11301-018-0149-3

Breiman L, Friedman JH, Olshen RA, Stone CJ (1984) Classification and regression trees. Wadsworth & Brooks/Cole Advanced Books & Software, Monterey, CA

Cirqueira D, Hofer M, Nedbal D, Helfert M, Bezbradica M (2020) Customer purchase behavior prediction in e-commerce: a conceptual framework and research Agenda. In: Ceci M, Loglisci C, Manco G, Masciari E, Raś Z (eds) New frontiers in mining complex patterns, vol 11948. Springer, Cham, pp 119–136. https://doi.org/10.1007/978-3-030-48861-1_8

Chapter   Google Scholar  

Clottey T, Benton WC (2014) Determining core acquisition quantities when products have long return lags. IIE Trans 46(9):880–893. https://doi.org/10.1080/0740817X.2014.882531

Cook SC, Yurchisin J (2017) Fast fashion environments: consumer’s heaven or retailer’s nightmare? Int J Retail Distrib Manag 45(2):143–157. https://doi.org/10.1108/IJRDM-03-2016-0027

Cui H, Rajagopalan S, Ward AR (2020) Predicting product return volume using machine learning methods. Eur J Oper Res 281(3):612–627. https://doi.org/10.1016/j.ejor.2019.05.046

Dalecke S, Karlsen R (2020) Designing dynamic and personalized nudges. In: Chbeir R, Manolopoulos Y, Akerkar R, Mizera-Pietraszko J (eds) Proceedings of the 10th international conference on web intelligence, mining and semantics. ACM, New York, pp 139–148. https://doi.org/10.1145/3405962.3405975

De P, Hu Y, Rahman MS (2013) Product-oriented web technologies and product returns: an exploratory study. Inf Syst Res 24(4):998–1010. https://doi.org/10.1287/isre.2013.0487

de Brito MP, Dekker R, Flapper SDP (2005) Reverse logistics: a review of case studies. In: Klose A, Fleischmann B (eds) Distribution logistics, vol 544. Springer. Berlin, Heidelberg, pp 243–281

Denyer D, Tranfield D (2009) Producing a systematic review. In: Buchanan DA, Bryman A (eds) The Sage handbook of organizational research methods. Sage, Thousand Oaks, CA, pp 671–689

Difrancesco RM, Huchzermeier A, Schröder D (2018) Optimizing the return window for online fashion retailers with closed-loop refurbishment. Omega 78:205–221. https://doi.org/10.1016/j.omega.2017.07.001

Diggins MA, Chen C, Chen J (2016) A review: customer returns in fashion retailing. In: Choi T-M (ed) Analytical modeling research in fashion business. Springer, Singapore, pp 31–48. https://doi.org/10.1007/978-981-10-1014-9_3

Ding Y, Xu H, Tan BCY (2016) Predicting product return rate with “tweets”. In: Proceedings of the 20th Pacific asia conference on information systems

Drechsler S, Lasch R (2015) Forecasting misused e-commerce consumer returns. In: Logistics management: proceedings of the 9th conference “Logistikmanagement”. Cham, pp 203–215.

Duong QH, Zhou L, Meng M, van Nguyen T, Ieromonachou P, Nguyen DT (2022) Understanding product returns: a systematic literature review using machine learning and bibliometric analysis. Int J Prod Econ 243:108340. https://doi.org/10.1016/j.ijpe.2021.108340

Esmeli R, Bader-El-Den M, Abdullahi H (2021) Towards early purchase intention prediction in online session based retailing systems. Electron Markets 31(3):697–715. https://doi.org/10.1007/s12525-020-00448-x

Fernández-Delgado M, Cernadas E, Barro S, Amorim D (2014) Do we need hundreds of classifiers to solve real world classification problems? J Mach Learn Res 15(1):3133–3181

Fisher RA (1936) The use of multiple measurements in taxonomic problems. Ann Eugen 7(2):179–188. https://doi.org/10.1111/j.1469-1809.1936.tb02137.x

Frei R, Jack L, Brown S (2020) Product returns: a growing problem for business, society and environment. IJOPM 40(10):1613–1621. https://doi.org/10.1108/IJOPM-02-2020-0083

Frei R, Jack L, Krzyzaniak S-A (2022) Mapping product returns processes in multichannel retailing: challenges and opportunities. Sustainability 14(3):1382. https://doi.org/10.3390/su14031382

Fu Y, Liu G, Papadimitriou S, Xiong H, Li X, Chen G (2016) Fused latent models for assessing product return propensity in online commerce. Decis Support Syst 91:77–88. https://doi.org/10.1016/j.dss.2016.08.002

Fuchs K, Lutz O (2021) A stitch in time saves nine–a meta-model for real-time prediction of product returns in ERP systems. In: Proceedings of the 29th european conference on information systems

Ge D, Pan Y, Shen Z-J, Di Wu, Yuan R, Zhang C (2019) Retail supply chain management: a review of theories and practices. J Data Manag 1:45–64. https://doi.org/10.1007/s42488-019-00004-z

Goedhart J, Haijema R, Akkerman R (2023) Modelling the influence of returns for an omni-channel retailer. Eur J Oper Res 306(3):1248–1263. https://doi.org/10.1016/j.ejor.2022.08.021

Goltsos TE, Ponte B, Wang SX, Liu Y, Naim MM, Syntetos AA (2019) The boomerang returns? Accounting for the impact of uncertainties on the dynamics of remanufacturing systems. Int J Prod Res 57(23):7361–7394. https://doi.org/10.1080/00207543.2018.1510191

Govindan K, Bouzon M (2018) From a literature review to a multi-perspective framework for reverse logistics barriers and drivers. J Clean Prod 187:318–337. https://doi.org/10.1016/j.jclepro.2018.03.040

Hachimi HEL, Oubrich M, Souissi O (2018) The optimization of reverse logistics activities: a literature review and future directions. In: Proceedings of the 5th IEEE international conference on technology management, operations and decisions, Piscataway, NJ, pp 18–24. https://doi.org/10.1109/ITMC.2018.8691285

Halevi G, Moed H, Bar-Ilan J (2017) Suitability of Google Scholar as a source of scientific information and as a source of data for scientific evaluation—review of the Literature. J Informet 11(3):823–834. https://doi.org/10.1016/j.joi.2017.06.005

Hamermesh DS (2007) Viewpoint: Replication in economics. Can J of Econ 40(3):715–733. https://doi.org/10.1111/j.1365-2966.2007.00428.x

Hastie T, Tibshirani R, Friedman JH (2017) The elements of statistical learning: data mining, inference, and prediction. Springer, New York, NY

Heilig L, Hofer J, Lessmann S, Voß S (2016) Data-driven product returns prediction: a cloud-based ensemble selection approach. In: Proceedings of the 24th european conference on information systems

Hess JD, Mayhew GE (1997) Modeling merchandise returns in direct marketing. J Direct Market 11(2):20–35. https://doi.org/10.1002/(SICI)1522-7138(199721)11:2<20:AID-DIR4>3.0.CO;2-#

Hevner A, March S, Park J, Ram S (2004) Design science in information systems research. MIS Q 28(1):75. https://doi.org/10.2307/25148625

Hofmann A, Gwinner F, Fuchs K, Winkelmann A (2020) An industry-agnostic approach for the prediction of return shipments. In: Proceedings of the 26th Americas conference on information systems, pp 1–10

Hong Y, Pavlou PA (2014) Product fit uncertainty in online markets: nature, effects, and antecedents. Inf Syst Res 25(2):328–344. https://doi.org/10.1287/isre.2014.0520

Imran AA, Amin MN (2020) Predicting the return of orders in the e-tail industry accompanying with model interpretation. Procedia Comput Sci 176:1170–1179. https://doi.org/10.1016/j.procs.2020.09.113

Jabareen Y (2009) Building a conceptual framework: philosophy, definitions, and procedure. Int J Qual Methods 8(4):49–62. https://doi.org/10.1177/160940690900800406

John S, Shah BJ, Kartha P (2020) Refund fraud analytics for an online retail purchases. J Bus Anal 3(1):56–66. https://doi.org/10.1080/2573234X.2020.1776164

Joshi T, Mukherjee A, Ippadi G (2018) One size does not fit all: predicting product returns in e-commerce platforms. In: Proceedings of the 10th IEEE/ACM international conference on advances in social networks analysis and mining, pp 926–927. https://doi.org/10.1109/ASONAM.2018.8508486

Kaiser D (2018) Individualized choices and digital nudging: multiple studies in digital retail channels. Karlsruher Institut für Technologie (KIT). https://doi.org/10.5445/IR/1000088341

Karl D, Asdecker B (2021) How does the Covid-19 pandemic affect consumer returns: an exploratory study. In: Proceedings of the 50th european marketing academy conference, vol 50

Karl D, Asdecker B, Feddersen-Arden C (2022) The impact of displaying quantity scarcity and relative discounts on sales and consumer returns in flash sale e-commerce. In: Proceedings of the 55th hawaii international conference on system sciences. https://doi.org/10.24251/HICSS.2022.556

Ketzenberg ME, Abbey JD, Heim GR, Kumar S (2020) Assessing customer return behaviors through data analytics. J Oper Manag 66(6):622–645. https://doi.org/10.1002/joom.1086

Kraus S, Breier M, Lim WM, Dabić M, Kumar S, Kanbach D, Mukherjee D, Corvello V, Piñeiro-Chousa J, Liguori E, Palacios-Marqués D, Schiavone F, Ferraris A, Fernandes C, Ferreira JJ (2022) Literature reviews as independent studies: guidelines for academic practice. Rev Manag Sci 16(8):2577–2595. https://doi.org/10.1007/s11846-022-00588-8

Lantz B, Hjort K (2013) Real e-customer behavioural responses to free delivery and free returns. Electron Commer Res 13(2):183–198. https://doi.org/10.1007/s10660-013-9125-0

Leitch G, Tanner JE (1991) Economic forecast evaluation: profits versus the conventional error measures. Am Econ Rev 81(3):580–590

Li X, Zhuang Y, Fu Y, He X (2019) A trust-aware random walk model for return propensity estimation and consumer anomaly scoring in online shopping. Sci China Inf Sci 62(5). https://doi.org/10.1007/s11432-018-9511-1

Li J, He J, Zhu Y (2018) E-tail product return prediction via hypergraph-based local graph cut. In: Proceedings of the 24th ACM sigkdd international conference on knowledge discovery & data mining, New York, NY, pp 519–527. https://doi.org/10.1145/3219819.3219829

Melacini M, Perotti S, Rasini M, Tappia E (2018) E-fulfilment and distribution in omni-channel retailing: a systematic literature review. Int Jnl Phys Dist Log Manage 48(4):391–414. https://doi.org/10.1108/IJPDLM-02-2017-0101

Mentzer JT, Kahn KB (1995) Forecasting technique familiarity, satisfaction, usage, and application. J Forecast 14(5):465–476. https://doi.org/10.1002/for.3980140506

Micol Policarpo L, da Silveira DE, da Rosa RR, Antunes Stoffel R, da Costa CA, Victória Barbosa JL, Scorsatto R, Arcot T (2021) Machine learning through the lens of e-commerce initiatives: an up-to-date systematic literature review. Comput Sci Rev 41:100414. https://doi.org/10.1016/j.cosrev.2021.100414

Miles MB, Huberman AM, Saldaña J (2020) Qualitative data analysis: A methods sourcebook. Sage, Los Angeles

National Retail Federation/Appriss Retail (2023) Consumer returns in the retail industry 2022. https://nrf.com/research/2022-consumer-returns-retail-industry . Accessed 23 May 2023

Ni J, Neslin SA, Sun B (2012) Database submission the ISMS durable goods data sets. Mark Sci 31(6):1008–1013. https://doi.org/10.1287/mksc.1120.0726

Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, Shamseer L, Tetzlaff JM, Akl EA, Brennan SE, Chou R, Glanville J, Grimshaw JM, Hróbjartsson A, Lalu MM, Li T, Loder EW, Mayo-Wilson E, McDonald S, McGuinness LA, Stewart LA, Thomas J, Tricco AC, Welch VA, Whiting P, Moher D (2021) The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. Syst Rev 10:89. https://doi.org/10.1186/s13643-021-01626-4

Pandya R, Pandya J (2015) C5.0 algorithm to improved decision tree with feature selection and reduced error pruning. IJCA 117(16):18–21. https://doi.org/10.5120/20639-3318

Petropoulos F, Apiletti D, Assimakopoulos V, Babai MZ, Barrow DK, Ben Taieb S, Bergmeir C, Bessa RJ, Bijak J, Boylan JE, Browell J, Carnevale C, Castle JL, Cirillo P, Clements MP, Cordeiro C, Cyrino Oliveira FL, de Baets S, Dokumentov A, Ellison J, Fiszeder P, Franses PH, Frazier DT, Gilliland M, Gönül MS, Goodwin P, Grossi L, Grushka-Cockayne Y, Guidolin M, Guidolin M, Gunter U, Guo X, Guseo R, Harvey N, Hendry DF, Hollyman R, Januschowski T, Jeon J, Jose VRR, Kang Y, Koehler AB, Kolassa S, Kourentzes N, Leva S, Li F, Litsiou K, Makridakis S, Martin GM, Martinez AB, Meeran S, Modis T, Nikolopoulos K, Önkal D, Paccagnini A, Panagiotelis A, Panapakidis I, Pavía JM, Pedio M, Pedregal DJ, Pinson P, Ramos P, Rapach DE, Reade JJ, Rostami-Tabar B, Rubaszek M, Sermpinis G, Shang HL, Spiliotis E, Syntetos AA, Talagala PD, Talagala TS, Tashman L, Thomakos D, Thorarinsdottir T, Todini E, Trapero Arenas JR, Wang X, Winkler RL, Yusupova A, Ziel F (2022) Forecasting: theory and practice. Int J Forecast 38(3):705–871. https://doi.org/10.1016/j.ijforecast.2021.11.001

Polikar R (2006) Ensemble based systems in decision making. IEEE Circuits Syst Mag 6(3):21–45. https://doi.org/10.1109/mcas.2006.1688199

Potdar A, Rogers J (2012) Reason-code based model to forecast product returns. Foresight 14(2):105–120. https://doi.org/10.1108/14636681211222393

Pur S, Stahl E, Wittmann M, Wittmann G, Weinfurtner S (2013) Retourenmanagement im Online-Handel–das Beste daraus machen: Daten, Fakten und Status quo. Ibi Research, Regensburg

Rajasekaran V, Priyadarshini R (2021) An e-commerce prototype for predicting the product return phenomenon using optimization and regression techniques. In: Singh M, Tyagi V, Gupta PK, Flusser J, Ören T, Sonawane VR (eds) Advances in computing and data sciences: proceedings of the 5th international conference on advances in computing and data sciences, 1st edn, vol 1441, pp 230–240. https://doi.org/10.1007/978-3-030-88244-0_22

Ravitch SM, Riggan M (2017) Reason and rigor: how conceptual frameworks guide research. Sage, Los Angeles, London, New Delhi, Singapore, Washington DC

Ren S, Chan H-L, Siqin T (2020) Demand forecasting in retail operations for fashionable products: methods, practices, and real case study. Ann Oper Res 291(1–2):761–777. https://doi.org/10.1007/s10479-019-03148-8

Rezaei M, Cribben I, Samorani M (2021) A clustering-based feature selection method for automatically generated relational attributes. Ann Oper Res 303(1–2):233–263. https://doi.org/10.1007/s10479-018-2830-2

Rogers DS, Lambert DM, Croxton KL, García-Dastugue SJ (2002) The returns management process. Int J Log Manag 13(2):1–18. https://doi.org/10.1108/09574090210806397

Röllecke FJ, Huchzermeier A, Schröder D (2018) Returning customers: the hidden strategic opportunity of returns management. Calif Manage Rev 60(2):176–203. https://doi.org/10.1177/0008125617741125

Sahoo N, Dellarocas C, Srinivasan S (2018) The impact of online product reviews on product returns. Inf Syst Res 29(3):723–738. https://doi.org/10.1287/isre.2017.0736

Samorani M, Ahmed F, Zaiane OR (2016) Automatic generation of relational attributes: an application to product returns. In: Proceedings of the 4th IEEE international conference on big data, pp 1454–1463

Santoro G, Fiano F, Bertoldi B, Ciampi F (2019) Big data for business management in the retail industry. MD 57(8):1980–1992. https://doi.org/10.1108/MD-07-2018-0829

Shaharudin MR, Zailani S, Tan KC (2015) Barriers to product returns and recovery management in a developing country: investigation using multiple methods. J Clean Prod 96:220–232. https://doi.org/10.1016/j.jclepro.2013.12.071

Shang G, McKie EC, Ferguson ME, Galbreth MR (2020) Using transactions data to improve consumer returns forecasting. J Oper Manag 66(3):326–348. https://doi.org/10.1002/joom.1071

Srivastava SK, Srivastava RK (2006) Managing product returns for reverse logistics. Int Jnl Phys Dist Log Manage 36(7):524–546. https://doi.org/10.1108/09600030610684962

Stock JR, Mulki JP (2009) Product returns processing: an examination of practices of manufacturers, wholesalers/distributors, and retailers. J Bus Logist 30(1):33–62. https://doi.org/10.1002/j.2158-1592.2009.tb00098.x

Stöcker B, Baier D, Brand BM (2021) New insights in online fashion retail returns from a customers’ perspective and their dynamics. J Bus Econ 91(8):1149–1187. https://doi.org/10.1007/s11573-021-01032-1

Sweidan D, Johansson U, Gidenstam A (2020) Predicting returns in men’s fashion. In: Proceedings of the 14th international fuzzy logic and intelligent technologies in nuclear science conference, pp 1506–1513. https://doi.org/10.1142/9789811223334_0180

Thaler RH, Sunstein CR (2009) Nudge: Improving decisions about health, wealth and happiness. Penguin

Tibben-Lembke RS, Rogers DS (2002) Differences between forward and reverse logistics in a retail environment. Supp Chain Mnagmnt 7(5):271–282. https://doi.org/10.1108/13598540210447719

Tibshirani R (1996) Regression shrinkage and selection via the lasso. J Roy Stat Soc: Ser B (Methodol) 58(1):267–288. https://doi.org/10.1111/j.2517-6161.1996.tb02080.x

Toktay LB, van der Laan EA, de Brito MP (2004) Managing product returns: the role of forecasting. In: Dekker R, Fleischmann M, Inderfurth K, van Wassenhove LN (eds) Reverse logistics. Springer, Berlin, Heidelberg, pp 45–64. https://doi.org/10.1007/978-3-540-24803-3_3

Toktay LB, Wein LM, Zenios SA (2000) Inventory management of remanufacturable products. Manage Sci 46(11):1412–142. https://doi.org/10.1287/mnsc.46.11.1412.12082

Tranfield D, Denyer D, Smart P (2003) Towards a methodology for developing evidence-informed management knowledge by means of systematic review. Br J Manag 14(3):207–222. https://doi.org/10.1111/1467-8551.00375

Uman LS (2011) Systematic reviews and meta-analyses. J Can Acad Child Adolesc Psychiatry 20(1):57–59

Urbanke P, Kranz J, Kolbe L (2015) Predicting product returns in e-commerce: the contribution of mahalanobis feature extraction. In: Proceedings of the 14th international conference on computer and information science

Urbanke P, Uhlig A, Kranz J (2017) A customized and interpretable deep neural network for high-dimensional business data–evidence from an e-commerce application. In: Proceedings of the 38th international conference on information systems

Vakulenko Y, Shams P, Hellström D, Hjort K (2019) Service innovation in e-commerce last mile delivery: mapping the e-customer journey. J Bus Res 101:461–468. https://doi.org/10.1016/j.jbusres.2019.01.016

vom Brocke J, Simons A, Niehaves B, Reimer K, Plattfaut R, Cleven A (2009) Reconstructing the giant: on the importance of rigour in documenting the literature search process. In: Proceedings of the 17 th european conference on information systems

von Zahn M, Bauer K, Mihale-Wilson C, Jagow J, Speicher M, Hinz O (2022) The smart green nudge: reducing product returns through enriched digital footprints and causal machine learning. SSRN J. https://doi.org/10.2139/ssrn.4262656

Walsh G, Möhring M (2017) Effectiveness of product return-prevention instruments: empirical evidence. Electron Mark 27(4):341–350. https://doi.org/10.1007/s12525-017-0259-0

Walsh G, Möhring M, Koot C, Schaarschmidt M (2014) Preventive product returns management systems–a review and model. In: Proceedings of the 22nd european conference on information systems

Webster J, Watson RT (2002) Analyzing the past to prepare for the future: writing a literature review. MIS Q 26(2):xiii–xxiii

Winklhofer H, Diamantopoulos A, Witt SF (1996) Forecasting practice: a review of the empirical literature and an agenda for future research. Int J Forecast 12(2):193–221. https://doi.org/10.1016/0169-2070(95)00647-8

Wirth R, Hipp J (2000) CRISP-DM: towards a standard process model for data mining. In: Proceedings of the 4th international conference on the practical applications of knowledge discovery and data mining, vol 1, pp 29–40

Zhao X, Hu S, Meng X (2020) Who should pay for return freight in the online retailing? Retailers or consumers. Electron Commer Res 20(2):427–452. https://doi.org/10.1007/s10660-019-09360-9

Zhu Y, Li J, He J, Quanz BL, Deshpande A (2018) A local algorithm for product return prediction in e-commerce. In: Proceedings of the 27th international joint conference on artificial intelligence, pp 3718–3724. https://doi.org/10.24963/ijcai.2018/517

Zotteri G, Kalchschmidt M (2007) Forecasting practices: empirical evidence and a framework for research. Int J Prod Econ 108(1–2):84–99. https://doi.org/10.1016/j.ijpe.2006.12.004

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Appendix: Author-centric content summary (with focus on forecasting issues)

1.1 journal publications.

Hess and Mayhew ( 1997 ) describe a forecasting approach, taking the example of a direct marketer for apparel with a lenient consumer return policy (free returns anytime). The analysis can plausibly be applied to a general retailer, although return time windows are somewhat different. A regression approach and a hazard model are compared. The regression approach itself is split into an OLS estimation of return timing (with poor fit) and a logit model of return propensities, which is in turn used for the split function of the box-cox-hazard approach for estimating the probability of a return over time. The accuracy was measured by fit statistics regarding the absolute deviation from the actual cumulative return proportion, with the split-hazard model outperforming the regression model. Besides price, the importance of fit of the respective product is used as a predictor.

Potdar and Rogers ( 2012 ) propose a method using reason codes combined with consumer behavior data for forecasting returns volume in the consumer electronics industry, aiming at the retailer stage as well as the preceding supply chain stages. The subject of their study is an offline retailer, which allows generalization for e-tailers due to a similar return policy (14 days free returns with no questions asked). In a multi-step approach, the authors are using essential statistical methods (moving averages, correlations, and linear regression), but use sophisticated domain and product knowledge like product features or price in relation to past return numbers, aiming to rank different competing products regarding their quality, and to predict the volume of returns for a given product for each given period of time.

Fu et al. ( 2016 ) derive a framework for the forecasting of product- and consumer-specific return propensities, i.e., the return propensity for individual purchases. Their study is directed at online shopping and is evaluated using the data from an online cosmetic retailer selling via Taobao.com. The predictors are categorized into inconsistencies in the buying and in the shipping phase of a transaction. A latent factor model is introduced for return propensities capturing differences between expectations and performance. This model is extended by product (e.g., warranty) and customer information (e.g., gender, credit score). The model is based on conditional probabilities, and an iterative expectation–maximization approach derives its parameters. MAE and RMSE, precision/recall, and AUC metrics assess the forecast accuracy. As benchmark models, two matrix factorization models and two memory-based models (historical consumer or product return rates) are compared, while the proposed model outperforms the references. Furthermore, this model allows identifying various return reasons, e.g., return abuse and fraud.

Building on the work of Fu et al. ( 2016 ), Li et al. ( 2019 ) investigate underlying reasons for consumer returns, taking the example and data of an online cosmetic retailer via Taobao.com. They examine the customers’ return propensity for product types, aiming at detecting abnormal returns suspecting abuse. Different from purchase decisions, they find customer profile data to be more important predictors for return decisions than product information or transaction details. The authors detect “selfish” or “fraud” consumers based on this rationale. For estimating return propensities for a given consumer and product, they calculate the return behavior depending on the return decision of similar consumers (“trust network”) and the amount of trust in these other consumers. MAE and precision-recall-measures are used to assess the prediction of different random walk models. The employed trust-based random walk model outperforms the other models on most indicators, building the basis for anomaly detection of consumers to cluster them into groups (honest/selfish/fraud) and individually address the return issues of these groups.

Although the paper from Cui et al. ( 2020 ) aims at product return forecasts from the perspective of the manufacturer, their case can be generalized for classic e-tailers, as the manufacturer is responsible for the return handling in their scenario—a task often performed by the retailer. They used a comprehensive data set from an automotive accessories manufacturer aiming to forecast return volume for sales channels and different products. The observed return rates lower than 1% are uncommonly low, and therefore the results must be interpreted with caution. First, a hierarchical OLS regression step-by-step incorporates up to 40 predictors regarding sales, time, product type, sales channel, and product details, including return history. The full model shows a significantly increased performance measured by a more than 50% decrease of MSE, which was used as the primary performance measure. Interestingly, relatively small differences in model quality (R 2 ) led to overproportional changes in the MSE. Using a machine-learning approach for predictor selection (“LASSO”), another MSE reduction of about 10% was achieved. Data Mining approaches (random forest, gradient boosting) could not outperform the LASSO approach. Forecasting performance was strongly dependent on the variation of the data. The two best predictors for return volume were past sales volume and lagged return statistics. The authors were wondering about the importance of lagged return information, failing to acknowledge that this predictor includes the consumer reaction to detailed product information, which has not been a significant predictor.

Ketzenberg et al. ( 2020 ) segment customers and target detecting the small number of abusive returners, as these are unprofitable for the retailer and generate significant losses over a long time. In general, high-returning customers are usually more profitable. The data used for this study is from a department store retailer with various product groups in the assortment. Predictors are transactional data and customer attributes. For classification, different algorithms like logit, Support Vector Machines (SVM), Random Forests (RF), Neural Networks (NN) are used in combination with different shrinkage methods like LASSO, ridge regression, and elastic net. Random Forests and especially Neural Networks outperform the other algorithms, assessed by sensitivity, precision, and AUC. In conclusion, a low rate of false positives could assure retailers of using abuse detection systems.

Shang et al. (Shang et al. 2020 ) developed a predict-aggregate (P-A) model adaptable both for retailers and manufacturers for forecasting return volume in a continuous timeframe, in contrast to commonly used aggregate-predict (A-P) models. Instead of aggregating data first (i.e., sales volume and returns volume), they first aggregate product-specific return probabilities and then aggregate the purchases by addition of the individual probabilities. As predictors, they only use timestamps and lagged return information. They tune and assess their models on two datasets from an offline electronics and an online jewelry retailer. ARIMA and lagged return models known from end-of-life forecasting (de Brito et al. 2005 ) are used as benchmarks, using RMSE as an assessment criterion. The authors show that even a basic version of their approach outperforms the benchmark models in almost all observed cases by up to 19%, though using only lagged returns and timestamps as input. Different extensions, e.g., including more predictor variables, can easily be integrated and are shown to further improve the forecasting performance.

John et al. ( 2020 ) try to predict the rare event of return fraud from customer representatives that make use of exactly knowing the e-commerce company’s return policy framework and buying and returning items fraudulently. Therefore, predictors range from transaction details to customer service agent attributes. A penalized likelihood logit model was chosen by the authors and was evaluated by precision and recall, focussing on maximizing recall and minimizing false negatives. The most important predictors were communication type and reason for interaction.

The paper by Rezaei et al. ( 2021 ) introduces a new algorithm to automatically select attributes from high-dimensional databases for forecasting purposes. As a demonstration sample, they use simulated data as well as the publicly available ISMS Durable Goods dataset (Ni et al. 2012 ) for consumer electronics. The results are assessed by AUC, precision, recall, and f1-score. They compare different configurations. For the simulated data, LASSO as shrinkage method generally works best, outperforming RF and BaggedTrees. For real-world data, based on a forecast with a logit model, they show that the proposed selection algorithm performs similar or better compared to LASSO, SVM, and RF, while the complexity of the chosen variables is lower.

1.2 Conference publications

Urbanke et al. ( 2015 ) describe a decision support system to better direct return-reducing interventions at e-commerce purchases with highly likely returns. They compare different approaches for extracting input variables for return propensity forecasting. They use a large dataset from a fashion e-tailer, aiming to reduce the input variables regarding consumer profile, product profile, and basket information from over 5,000 binary variables to 10 numeric variables by different algorithms (e.g., principal component analysis, non-negative matrix factorization, etc.). The results are then used to predict return propensities with a wide variety of state-of-the-art algorithms (AdaBoost, CART, ERT, GB, LDA, LR, RF, SVM), thus also revealing both feature selection and prediction performance. The proposed Mahalanobis feature extraction algorithm used as input for AdaBoost outperforms all other combinations presented, while interestingly, a logit model with all original inputs delivers relatively precise forecasts.

Building on some parts of this study, the paper of Urbanke et al. ( 2017 ) presents a return decision forecasting approach and aims at two targets, (1) high predictive accuracy and (2) interpretability of the model. Based on real-world data of a fashion and sports e-tailer, they first hand-craft 18 input variables and then use NN to extract more features and compare this approach to other feature extraction algorithms based on different forecasting algorithms. For assessment, they measure correlations between out-of-sample-predictions and class labels and AUC. The best performing classifier was AdaBoost, while the contribution of NN-based feature extraction shows interpretability as well as superior predictive performance.

Ahmed et al. ( 2016 ) focus on the automatic aggregation and integration of different data sources to generate input variables (features). They use return forecasting just as an exemplary classification problem for their data preparation approach, using various ML algorithms, e.g., RF, NN, DT-based algorithms, to detect returned purchases of an electronics retailer. Based on AUC measure, the results of their GARP-approach are superior to not using aggregations while generating an extensive amount of features with no pruning approach. In general, SVM and RF work best in combination with the proposed GARP approach. The data is based on the publicly available ISMS durable goods data sets (Ni et al. 2012 ).

A similar group of authors published another paper (Samorani et al. 2016 ), again using the aforementioned ISMS dataset as an example for data preparation and automatic attribute generation. Besides forecasting performance, in this paper, they want to generate knowledge about important return predictors; e.g., a higher price is associated with more returns, but only as long price levels are below a 1,500$ threshold. AUC is used to assess different levels of data integration, confirming that overfitting might happen when too many attributes are used.

Heilig et al. ( 2016 ) describe a Forecasting Support System (FSS) to predict return decisions in a real environment. First, they compare different forecasting approaches for data from a fashion e-tailer, assessed by AUC and accuracy metrics. The ensemble selection approach outperforms all other classifiers, with RF being the closest competitor. Computational times grow exponentially when using more data. Based on these results, they secondly describe a cloud framework for implementing such ensemble models for live use in a real shop environment.

Ding et al. ( 2016 ) present an approach to predict the daily return rate of an e-commerce company based on sentiment analysis of tweets regarding this company in the categories of news, experience, products, and service. Therefore, they use sophisticated text mining technologies, while the forecasting approach of an econometric vector autoregression is more or less common. The emotion of posts regarding different variables (news, product, service) impacts the returns rate negatively, while the emotion of purchasing experience impacts it positively, showing that the prediction accuracy enhances through classifying social network posts.

Drechsler and Lasch ( 2015 ) aim at forecasting the volume of fraudulent returns in e-commerce over several periods of time. They present different approaches multiplying the sales volume and the relative return rate, the first referring to Potdar and Rogers ( 2012 ), estimating the rate of misused returns directly based on time-lag-specific return rates. In a second approach referring to Toktay et al. ( 2000 ), they estimate the overall returns rate and multiply it by the time-specific ratio of fraudulent returns. The return rates were forecasted by moving averages and exponential smoothing techniques. Assessment criteria for performance comparison based on simulated data were MAE, MAPE, and TIC, showing the first approach to be superior, but both methods are not sufficiently robust. Therefore, the authors include further time-specific information (like promotions or special events, which could foster fraudulent returns) in a model using a Holt-Winters approach, showing superior performance. All of the models are highly dependent on low fluctuation in return rates, showing a shortcoming of these more or less naive forecasting techniques.

Asdecker and Karl ( 2018 ) compare the performance of different algorithms for forecasting binary return decisions: logit, linear discriminant analysis, neuronal networks, and a decision-tree-based algorithm (C5.0). Their analysis is based on the data of a fashion e-tailer, including price, consumer information, and shipment information (number of articles in shipment, delivery time). For the assessment of different algorithms, they use the total absolut error (TAE) and relative error. An ensemble learning approach performs best and similar to the C5.0 algorithm. Though, differences in performance are relatively small, while only about 68% of return decisions are forecasted correctly.

Li et al. ( 2018 ) propose a hypergraph representation of historical purchase and return information combined with a random-walk-based local graph cut algorithm to forecast return decisions on order (basket) level as well as on product level. By this, they aim to detect the underlying return causes. They use data from two omnichannel fashion e-tailers from the US and Europe to assess the performance of their approach, using precision/recall/F 0.5 /AUC metrics while arguing that precision is the most important indicator for targeted interventions. Three similarity-based approaches (e.g., a k-Nearest Neighbor model) are used as reference. The proposed approach performs best regarding AUC, precision, and F 0.5 metrics.

Zhu et al. ( 2018 ) developed a weighted hybrid graph algorithm representing historical customer behavior and customer/product similarity, combined with a random-walk-based algorithm for predicting customer/product combinations that will be returned. They report an experiment based on data from a European fashion e-tailer suffering from return rates as high as 50%. For assessment, they use precision, recall, and F 0.5 metrics. Their approach is superior to two reference competitors (similarity-based and a bipartite graph algorithm). As predictors, they use product similarities and historical return information, while their approach can be enriched with detailed customer attributes.

Joshi et al. ( 2018 ) model the return decisions based on the data of an Indian e-commerce company, especially dealing with returns for apparel due to fit issues. In a two-step approach, they first model return probabilities using concepts from network science based on a customer’s historical purchase and return decisions, and secondly use a SVM implementation with return probabilities as a single input to classify for the return decision. Assessed by F 1 /precision/recall scores, their approach is superior to a reference random-walk baseline model.

Imran and Amin ( 2020 ) compare different forecasting algorithms (XGBoost, CatBoost, LightGBM, TabNet) for return classification based on the data of a general e-commerce retailer from Bangladesh. As input variables, only order attributes, including payment method and order medium, are used. For evaluation, they use metrics like true negative rate, false-positive rate, false-negative rate, true positive rate, AUC, F 2 -score, precision, and accuracy. In the end, they chose TPR, AUC, and F 2 -score, claiming that misclassifying high return probability objects were the first thing to avoid. According to these metrics, TabNet as a deep learning algorithm outperforms the other models. The most important predictors were payment method, order location, and promotional orders.

As returns are most prominent in fashion e-commerce, most of the forecasting papers take this industry as an example, as forecasting models are more precise when returns are more frequent. Hofmann et al. ( 2020 ) develop a more generalized order-based return decision forecasting approach, appropriate for different industries and suitable also for low return rates. For their analysis, they use a dataset from a german technical wholesaler with a return rate as low as 5%. Input variables were just basket composition and return information. For assessment, they used precision and recall metrics. RF did not perform superior to a statistical baseline approach, nor with oversampling as data preparation, to deal with the group imbalance. The DART algorithm makes use of the group imbalance correction by random oversampling. In general, gradient boosting performs best with imbalanced groups, also without oversampling, but forecasting quality is lower than with more specialized forecasting approaches as described for fashion. Furthermore, results were more accurate on basket level than on single-item level.

Fuchs and Lutz ( 2021 ) use Design Science Research (DSR) principles to design a meta-model for the real-time prediction of returns. The goal is to influence consumer decisions by triggering a feedback system based on the basket composition and its return probability. For forecasting, which is not the primary focus of their paper, they build upon a gradient boosting model taken from existing research (Hofmann et al. 2020 ) and describe possible implementations into an ERP system regarding asynchronous communication requirements and possible architecture.

The paper by Sweidan et al. ( 2020 ) evaluates the forecasting performance of a random forest model for a shipment-based return decision, using real-world data of a fashion e-tailer. For their model, they use customer (e.g., lagged return rate) and order information as inputs. They find that predictions with high confidence are very precise (i.e., low false-positive rate). Thus, interventions can be targeted at such orders already when the items are in the consumers’ basket without risk of a misdirected intervention. For assessment, accuracy, AUC, precision, recall and specificity are used. Regarding the predictors, they note that selection orders (a product in different sizes) are the best predictor for order-based returns.

Rajasekaran and Priyadarshini ( 2021 ) develop a metaheuristic for forecasting the product-based return probabilities. In the first step, they determine return probabilities based on product feedback, time, and product attributes regarding manufacturer return statistics. Secondly, they compare different algorithms (OLS, RF, Gradient Boosting) by MAE, MSE, and RMSE metrics. Interestingly, linear regression performs best in all metrics, but no explanation and a misinterpretation regarding the best algorithm are given.

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Karl, D. Forecasting e-commerce consumer returns: a systematic literature review. Manag Rev Q (2024). https://doi.org/10.1007/s11301-024-00436-x

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Systematic literature review of real-world evidence for treatments in HR+/HER2- second-line LABC/mBC after first-line treatment with CDK4/6i

• Veronique Lambert   ORCID: orcid.org/0000-0002-6984-0038 1 ,
• Sarah Kane   ORCID: orcid.org/0009-0006-9341-4836 2   na1 ,
• Belal Howidi   ORCID: orcid.org/0000-0002-1166-7631 2   na1 ,
• Bao-Ngoc Nguyen   ORCID: orcid.org/0000-0001-6026-2270 2   na1 ,
• David Chandiwana   ORCID: orcid.org/0009-0002-3499-2565 3 ,
• Yan Wu   ORCID: orcid.org/0009-0008-3348-9232 1 ,
• Michelle Edwards   ORCID: orcid.org/0009-0001-4292-3140 3 &
• Imtiaz A. Samjoo   ORCID: orcid.org/0000-0003-1415-8055 2   na1  

BMC Cancer volume  24 , Article number:  631 ( 2024 ) Cite this article

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Metrics details

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) combined with endocrine therapy (ET) are currently recommended by the National Comprehensive Cancer Network (NCCN) guidelines and the European Society for Medical Oncology (ESMO) guidelines as the first-line (1 L) treatment for patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative, locally advanced/metastatic breast cancer (HR+/HER2- LABC/mBC). Although there are many treatment options, there is no clear standard of care for patients following 1 L CDK4/6i. Understanding the real-world effectiveness of subsequent therapies may help to identify an unmet need in this patient population. This systematic literature review qualitatively synthesized effectiveness and safety outcomes for treatments received in the real-world setting after 1 L CDK4/6i therapy in patients with HR+/ HER2- LABC/mBC.

MEDLINE®, Embase, and Cochrane were searched using the Ovid® platform for real-world evidence studies published between 2015 and 2022. Grey literature was searched to identify relevant conference abstracts published from 2019 to 2022. The review was conducted in accordance with PRISMA guidelines (PROSPERO registration: CRD42023383914). Data were qualitatively synthesized and weighted average median real-world progression-free survival (rwPFS) was calculated for NCCN/ESMO-recommended post-1 L CDK4/6i treatment regimens.

Twenty records (9 full-text articles and 11 conference abstracts) encompassing 18 unique studies met the eligibility criteria and reported outcomes for second-line (2 L) treatments after 1 L CDK4/6i; no studies reported disaggregated outcomes in the third-line setting or beyond. Sixteen studies included NCCN/ESMO guideline-recommended treatments with the majority evaluating endocrine-based therapy; five studies on single-agent ET, six studies on mammalian target of rapamycin inhibitors (mTORi) ± ET, and three studies with a mix of ET and/or mTORi. Chemotherapy outcomes were reported in 11 studies. The most assessed outcome was median rwPFS; the weighted average median rwPFS was calculated as 3.9 months (3.3-6.0 months) for single-agent ET, 3.6 months (2.5–4.9 months) for mTORi ± ET, 3.7 months for a mix of ET and/or mTORi (3.0–4.0 months), and 6.1 months (3.7–9.7 months) for chemotherapy. Very few studies reported other effectiveness outcomes and only two studies reported safety outcomes. Most studies had heterogeneity in patient- and disease-related characteristics.

Conclusions

The real-world effectiveness of current 2 L treatments post-1 L CDK4/6i are suboptimal, highlighting an unmet need for this patient population.

Peer Review reports

Introduction

Breast cancer (BC) is the most diagnosed form of cancer in women with an estimated 2.3 million new cases diagnosed worldwide each year [ 1 ]. BC is the second leading cause of cancer death, accounting for 685,000 deaths worldwide per year [ 2 ]. By 2040, the global burden associated with BC is expected to surpass three million new cases and one million deaths annually (due to population growth and aging) [ 3 ]. Numerous factors contribute to global disparities in BC-related mortality rates, including delayed diagnosis, resulting in a high number of BC cases that have progressed to locally advanced BC (LABC) or metastatic BC (mBC) [ 4 , 5 , 6 ]. In the United States (US), the five-year survival rate for patients who progress to mBC is three times lower (31%) than the overall five-year survival rate for all stages (91%) [ 6 , 7 ].

Hormone receptor (HR) positive (i.e., estrogen receptor and/or progesterone receptor positive) coupled with negative human epidermal growth factor 2 (HER2) expression is the most common subtype of BC, accounting for ∼ 60–70% of all BC cases [ 8 , 9 ]. Historically, endocrine therapy (ET) through estrogen receptor modulation and/or estrogen deprivation has been the standard of care for first-line (1 L) treatment of HR-positive/HER2-negative (HR+/HER2-) mBC [ 10 ]. However, with the approval of the cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) palbociclib in combination with the aromatase inhibitor (AI) letrozole in 2015 by the US Food and Drug Administration (FDA), 1 L treatment practice patterns have evolved such that CDK4/6i (either in combination with AIs or with fulvestrant) are currently considered the standard of care [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. Other CDK4/6i (ribociclib and abemaciclib) in combination with ET are approved for the treatment of HR+/HER2- LABC/mBC; 1 L use of ribociclib in combination with an AI was granted FDA approval in March 2017 for postmenopausal women (with expanded approval in July 2018 for pre/perimenopausal women and for use in 1 L with fulvestrant for patients with disease progression on ET as well as for postmenopausal women), and abemaciclib in combination with fulvestrant was granted FDA approval in September 2017 for patients with disease progression following ET and as monotherapy in cases where disease progression occurs following ET and prior chemotherapy in mBC (with expanded approval in February 2018 for use in 1 L in combination with an AI for postmenopausal women) [ 18 , 19 , 20 , 21 ].

Clinical trials investigating the addition of CDK4/6i to ET have demonstrated significant improvement in progression-free survival (PFS) and significant (ribociclib) or numerical (palbociclib and abemaciclib) improvement in overall survival (OS) compared to ET alone in patients with HR+/HER2- advanced or mBC, making this combination treatment the recommended option in the 1 L setting [ 22 , 23 , 24 , 25 , 26 , 27 ]. However, disease progression occurs in a significant portion of patients after 1 L CDK4/6i treatment [ 28 ] and the optimal treatment sequence after progression on CDK4/6i remains unclear [ 29 ]. At the time of this review (literature search conducted December 14, 2022), guidelines by the National Comprehensive Cancer Network (NCCN) and the European Society for Medical Oncology (ESMO) recommend various options for the treatment of HR+/HER2- advanced BC in the second-line (2 L) setting, including fulvestrant monotherapy, mammalian target of rapamycin inhibitors (mTORi; e.g., everolimus) ± ET, alpelisib + fulvestrant (if phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha mutation positive [PIK3CA-m+]), poly-ADP ribose polymerase inhibitors (PARPi) including olaparib or talazoparib (if breast cancer gene/partner and localizer of BRCA2 positive [BRCA/PALB2m+]), and chemotherapy (in cases when a visceral crisis is present) [ 15 , 16 ]. CDK4/6i can also be used in 2 L [ 16 , 30 ]; however, limited data are available to support CDK4/6i rechallenge after its use in the 1 L setting [ 15 ]. Depending on treatments used in the 1 L and 2 L settings, treatment in the third-line setting is individualized based on the patient’s response to prior treatments, tumor load, duration of response, and patient preference [ 9 , 15 ]. Understanding subsequent treatments after 1 L CDK4/6i, and their associated effectiveness, is an important focus in BC research.

Treatment options for HR+/HER2- LABC/mBC continue to evolve, with ongoing research in both clinical trials and in the real-world setting. Real-world evidence (RWE) offers important insights into novel therapeutic regimens and the effectiveness of treatments for HR+/HER2- LABC/mBC. The effectiveness of the current treatment options following 1 L CDK4/6i therapy in the real-world setting highlights the unmet need in this patient population and may help to drive further research and drug development. In this study, we conducted a systematic literature review (SLR) to qualitatively summarize the effectiveness and safety of treatment regimens in the real-world setting after 1 L treatment with CDK4/6i in patients with HR+/HER2- LABC/mBC.

Literature search

An SLR was performed in accordance with the Cochrane Handbook for Systematic Reviews of Interventions [ 31 ] and reported in alignment with the Preferred Reporting Items for Systematic Literature Reviews and Meta-Analyses (PRISMA) statement [ 32 ] to identify all RWE studies assessing the effectiveness and safety of treatments used for patients with HR+/HER2- LABC/mBC following 1 L CDK4/6i therapy and received subsequent treatment in 2 L and beyond (2 L+). The Ovid® platform was used to search MEDLINE® (including Epub Ahead of Print and In-Process, In-Data-Review & Other Non-Indexed Citations), Ovid MEDLINE® Daily, Embase, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews by an experienced medical information specialist. The MEDLINE® search strategy was peer-reviewed independently by a senior medical information specialist before execution using the Peer Review of Electronic Search Strategies (PRESS) checklist [ 33 ]. Searches were conducted on December 14, 2022. The review protocol was developed a priori and registered with the International Prospective Register of Systematic Review (PROSPERO; CRD42023383914) which outlined the population, intervention, comparator, outcome, and study design (PICOS) criteria and methodology used to conduct the review (Table  1 ).

Search strategies utilized a combination of controlled vocabulary (e.g., “HER2 Breast Cancer” or “HR Breast Cancer”) and keywords (e.g., “Retrospective studies”). Vocabulary and syntax were adjusted across databases. Published and validated filters were used to select for study design and were supplemented using additional medical subject headings (MeSH) terms and keywords to select for RWE and nonrandomized studies [ 34 ]. No language restrictions were included in the search strategy. Animal-only and opinion pieces were removed from the results. The search was limited to studies published between January 2015 and December 2022 to reflect the time at which FDA approval was granted for the first CDK4/6i agent (palbociclib) in combination with AI for the treatment of LABC/mBC [ 35 ]. Further search details are presented in Supplementary Material 1 .

Grey literature sources were also searched to identify relevant abstracts and posters published from January 2019 to December 2022 for prespecified relevant conferences including ESMO, San Antonio Breast Cancer Symposium (SABCS), American Society of Clinical Oncology (ASCO), the International Society for Pharmacoeconomics and Outcomes Research (ISPOR US), and the American Association for Cancer Research (AACR). A search of ClinicalTrials.gov was conducted to validate the findings from the database and grey literature searches.

Study selection, data extraction & weighted average calculation

Studies were screened for inclusion using DistillerSR Version 2.35 and 2.41 (DistillerSR Inc. 2021, Ottawa, Canada) by two independent reviewers based on the prespecified PICOS criteria (Table  1 ). A third reviewer was consulted to resolve any discrepancies during the screening process. Studies were included if they reported RWE on patients aged ≥ 18 years with HR+/HER2- LABC/mBC who received 1 L CDK4/6i treatment and received subsequent treatment in 2 L+. Studies were excluded if they reported the results of clinical trials (i.e., non-RWE), were published in any language other than English, and/or were published prior to 2015 (or prior to 2019 for conference abstracts and posters). For studies that met the eligibility criteria, data relating to study design and methodology, details of interventions, patient eligibility criteria and baseline characteristics, and outcome measures such as efficacy, safety, tolerability, and patient-reported outcomes (PROs), were extracted (as available) using a Microsoft Excel®-based data extraction form (Microsoft Corporation, WA, USA). Data extraction was performed by a single reviewer and was confirmed by a second reviewer. Multiple publications identified for the same RWE study, patient population, and setting that reported data for the same intervention were linked and extracted as a single publication. Weighted average median real-world progression-free survival (rwPFS) values were calculated by considering the contribution to the median rwPFS of each study proportional to its respective sample size. These weighted values were then used to compute the overall median rwPFS estimate.

Quality assessment

The Newcastle-Ottawa scale (NOS) for nonrandomized (cohort) studies was used to assess the risk of bias for published, full-text studies [ 36 ]. The NOS allocates a maximum of nine points for the least risk of bias across three domains: (1) Formation of study groups (four points), (2) Comparability between study groups (two points), (3) Outcome ascertainment (three points). NOS scores can be categorized in three groups: very high risk of bias (0 to 3 points), high risk of bias (4 to 6), and low risk of bias (7 to 9) [ 37 ]. Risk of bias assessment was performed by one reviewer and validated by a second independent reviewer to verify accuracy. Due to limited methodological data by which to assess study quality, risk of bias assessment was not performed on conference abstracts or posters. An amendment to the PROSPERO record (CRD42023383914) for this study was submitted in relation to the quality assessment method (specifying usage of the NOS).

The database search identified 3,377 records; after removal of duplicates, 2,759 were screened at the title and abstract stage of which 2,553 were excluded. Out of the 206 reports retrieved and assessed for eligibility, an additional 187 records were excluded after full-text review; most of these studies were excluded for having patients with mixed lines of CDK4/6i treatment (i.e., did not receive CDK4/6i exclusively in 1 L) (Fig.  1 and Table S1 ). The grey literature search identified 753 records which were assessed for eligibility; of which 752 were excluded mainly due to the population not meeting the eligibility criteria (Fig.  1 ). In total, the literature searches identified 20 records (9 published full-text articles and 11 conference abstracts/posters) representing 18 unique RWE studies that met the inclusion criteria. The NOS quality scores for the included full-text articles are provided in Table S2 . The scores ranged from four to six points (out of a total score of nine) and the median score was five, indicating that all the studies suffered from a high risk of bias [ 37 ].

Most studies were retrospective analyses of chart reviews or medical registries, and all studies were published between 2017 and 2022 (Table S3 ). Nearly half of the RWE studies (8 out of 18 studies) were conducted in the US [ 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ], while the remaining studies included sites in Canada, China, Germany, Italy, Japan, and the United Kingdom [ 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 ]. Sample sizes ranged from as few as 4 to as many as 839 patients across included studies, with patient age ranging from 26 to 86 years old.

Although treatment characteristics in the 1 L setting were not the focus of the present review, these details are captured in Table S3 . Briefly, several RWE studies reported 1 L CDK4/6i use in combination with ET (8 out of 18 studies) or as monotherapy (2 out of 18 studies) (Table S3 ). Treatments used in combination with 1 L CDK4/6i included letrozole, fulvestrant, exemestane, and anastrozole. Where reported (4 out of 18 studies), palbociclib was the most common 1 L CDK4/6i treatment. Many studies (8 out of 18 studies) did not report which specific CDK4/6i treatment(s) were used in 1 L or if its administration was in combination or monotherapy.

Characteristics of treatments after 1 L CDK4/6i therapy

Across all studies included in this review, effectiveness and safety data were only available for treatments administered in the 2 L setting after 1 L CDK4/6i treatment. No studies were identified that reported outcomes for patients treated in the third-line setting or beyond after 1 L CDK4/6i treatment. All 18 studies reported effectiveness outcomes in 2 L, with only two of these studies also describing 2 L safety outcomes. The distribution of outcomes reported in these studies is provided in Table S4 . Studies varied in their reporting of outcomes for 2 L treatments; some studies reported outcomes for a group of 2 L treatments while others described independent outcomes for specific 2 L treatments (i.e., everolimus, fulvestrant, or chemotherapy agents such as eribulin mesylate) [ 42 , 45 , 50 , 54 , 55 ]. Due to the heterogeneity in treatment classes reported in these studies, this data was categorized (as described below) to align with the guidelines provided by NCCN and ESMO [ 15 , 16 ]. The treatment class categorizations for the purpose of this review are: single-agent ET (patients who exclusively received a single-agent ET after 1 L CDK4/6i treatment), mTORi ± ET (patients who exclusively received an mTORi with or without ET after 1 L CDK4/6i treatment), mix of ET and/or mTORi (patients who may have received only ET, only mTORi, and/or both treatments but the studies in this group lacked sufficient information to categorize these patients in the “single-agent ET” or “mTOR ± ET” categories), and chemotherapy (patients who exclusively received chemotherapy after 1 L CDK4/6i treatment). Despite ESMO and NCCN guidelines indicating that limited evidence exists to support rechallenge with CDK4/6i after 1 L CDK4/6i treatment [ 15 , 16 ], two studies reported outcomes for this treatment approach. Data for such patients were categorized as “ CDK4/6i ± ET ” as it was unclear how many patients receiving CDK4/6i rechallenge received concurrent ET. All other patient groups that lacked sufficient information or did not report outcome/safety data independently (i.e., grouped patients with mixed treatments) to categorize as one of the treatment classes described above were grouped as “ other ”.

The majority of studies reported effectiveness outcomes for endocrine-based therapy after 1 L CDK4/6i treatment; five studies for single-agent ET, six studies for mTORi ± ET, and three studies for a mix of ET and/or mTORi (Fig.  2 ). Eleven studies reported effectiveness outcomes for chemotherapy after 1 L CDK4/6i treatment, and only two studies reported effectiveness outcomes for CDK4/6i rechallenge ± ET. Eight studies that described effectiveness outcomes were grouped into the “other” category. Safety data was only reported in two studies: one study evaluating the chemotherapy agent eribulin mesylate and one evaluating the mTORi everolimus.

Effectiveness outcomes

Real-world progression-free survival

Median rwPFS was described in 13 studies (Tables  2 and Table S5 ). Across the 13 studies, the median rwPFS ranged from 2.5 months [ 49 ] to 17.3 months [ 39 ]. Out of the 13 studies reporting median rwPFS, 10 studies reported median rwPFS for a 2 L treatment recommended by ESMO and NCCN guidelines, which ranged from 2.5 months [ 49 ] to 9.7 months [ 45 ].

Weighted average median rwPFS was calculated for 2 L treatments recommended by both ESMO and NCCN guidelines (Fig.  3 ). The weighted average median rwPFS for single-agent ET was 3.9 months ( n  = 92 total patients) and was derived using data from two studies reporting median rwPFS values of 3.3 months ( n  = 70) [ 38 ] and 6.0 months ( n  = 22) [ 40 ]. For one study ( n  = 7) that reported outcomes for single agent ET, median rwPFS was not reached during the follow-up period; as such, this study was excluded from the weighted average median rwPFS calculation [ 49 ].

The weighted average median rwPFS for mTORi ± ET was 3.6 months ( n  = 128 total patients) and was derived based on data from 3 studies with median rwPFS ranging from 2.5 months ( n  = 4) [ 49 ] to 4.9 months ( n  = 25) [ 54 ] (Fig.  3 ). For patients who received a mix of ET and/or mTORi but could not be classified into the single-agent ET or mTORi ± ET treatment classes, the weighted average median rwPFS was calculated to be 3.7 months ( n  = 17 total patients). This was calculated based on data from two studies reporting median rwPFS values of 3.0 months ( n  = 5) [ 46 ] and 4.0 months ( n  = 12) [ 49 ]. Notably, one study of patients receiving ET and/or everolimus reported a median rwPFS duration of 3.0 months; however, this study was excluded from the weighted average median rwPFS calculation for the ET and/or mTORi class as the sample size was not reported [ 53 ].

The weighted average median rwPFS for chemotherapy was 6.1 months ( n  = 499 total patients), calculated using data from 7 studies reporting median rwPFS values ranging from 3.7 months ( n  = 249) [ 38 ] to 9.7 months ( n  = 121) [ 45 ] (Fig.  3 ). One study with a median rwPFS duration of 5.6 months was not included in the weighted average median rwPFS calculation as the study did not report the sample size [ 53 ]. A second study was excluded from the calculation since the reported median rwPFS was not reached during the study period ( n  = 7) [ 41 ].

Although 2 L CDK4/6i ± ET rechallenge lacks sufficient information to support recommendation by ESMO and NCCN guidelines, the limited data currently available for this treatment have shown promising results. Briefly, two studies reported median rwPFS for CDK4/6i ± ET with values of 8.3 months ( n  = 302) [ 38 ] and 17.3 months ( n  = 165) (Table  2 ) [ 39 ]. The remaining median rwPFS studies reported data for patients classified as “Other” (Table S5 ). The “Other” category included median rwPFS outcomes from seven studies, and included a myriad of treatments (e.g., ET, mTOR + ET, chemotherapy, CDK4/6i + ET, alpelisib + fulvestrant, chidamide + ET) for which disaggregated median rwPFS values were not reported.

Overall survival

Median OS for 2 L treatment was reported in only three studies (Table  2 ) [ 38 , 42 , 43 ]. Across the three studies, the 2 L median OS ranged from 5.2 months ( n  = 3) [ 43 ] to 35.7 months ( n  = 302) [ 38 ]. Due to the lack of OS data in most of the studies, weighted averages could not be calculated. No median OS data was reported for the single-agent ET treatment class whereas two studies reported median OS for the mTORi ± ET treatment class, ranging from 5.2 months ( n  = 3) [ 43 ] to 21.8 months ( n  = 54) [ 42 ]. One study reported 2 L median OS of 24.8 months for a single patient treated with chemotherapy [ 43 ]. The median OS data in the CDK4/6i ± ET rechallenge group was 35.7 months ( n  = 302) [ 38 ].

Patient mortality was reported in three studies [ 43 , 44 , 45 ]. No studies reported mortality for the single-agent ET treatment class and only one study reported this outcome for the mTORi ± ET treatment class, where 100% of patients died ( n  = 3) as a result of rapid disease progression [ 43 ]. For the chemotherapy class, one study reported mortality for one patient receiving 2 L capecitabine [ 43 ]. An additional study reported eight deaths (21.7%) following 1 L CDK4/6i treatment; however, this study did not disclose the 2 L treatments administered to these patients [ 44 ].

Other clinical endpoints

The studies included limited information on additional clinical endpoints; two studies reported on time-to-discontinuation (TTD), two reported on duration of response (DOR), and one each on time-to-next-treatment (TTNT), time-to-progression (TTP), objective response rate (ORR), clinical benefit rate (CBR), and stable disease (Tables  2 and Table S5 ).

Safety, tolerability, and patient-reported outcomes

Safety and tolerability data were reported in two studies [ 40 , 45 ]. One study investigating 2 L administration of the chemotherapy agent eribulin mesylate reported 27 patients (22.3%) with neutropenia, 3 patients (2.5%) with febrile neutropenia, 10 patients (8.3%) with peripheral neuropathy, and 14 patients (11.6%) with diarrhea [ 45 ]. Of these, neutropenia of grade 3–4 severity occurred in 9 patients (33.3%) [ 45 ]. A total of 55 patients (45.5%) discontinued eribulin mesylate treatment; 1 patient (0.83%) discontinued treatment due to adverse events [ 45 ]. Another study reported that 5 out of the 22 patients receiving the mTORi everolimus combined with ET in 2 L (22.7%) discontinued treatment due to toxicity [ 40 ]. PROs were not reported in any of the studies included in the SLR.

The objective of this study was to summarize the existing RWE on the effectiveness and safety of therapies for patients with HR+/HER2- LABC/mBC after 1 L CDK4/6i treatment. We identified 18 unique studies reporting specifically on 2 L treatment regimens after 1 L CDK4/6i treatment. The weighted average median rwPFS for NCCN- and ESMO- guideline recommended 2 L treatments ranged from 3.6 to 3.9 months for ET-based treatments and was 6.1 months when including chemotherapy-based regimens. Treatment selection following 1 L CDK4/6i therapy remains challenging primarily due to the suboptimal effectiveness or significant toxicities (e.g., chemotherapy) associated with currently available options [ 56 ]. These results highlight that currently available 2 L treatments for patients with HR+/HER2- LABC/mBC who have received 1 L CDK4/6i are suboptimal, as evidenced by the brief median rwPFS duration associated with ET-based treatments, or notable side effects and toxicity linked to chemotherapy. This conclusion is aligned with a recent review highlighting the limited effectiveness of treatment options for HR+/HER2- LABC/mBC patients post-CDK4/6i treatment [ 56 , 57 ]. Registrational trials which have also shed light on the short median PFS of 2–3 months achieved by ET (i.e., fulvestrant) after 1 L CDK4/6i therapy emphasize the need to develop improved treatment strategies aimed at prolonging the duration of effective ET-based treatment [ 56 ].

The results of this review reveal a paucity of additional real-world effectiveness and safety evidence after 1 L CDK4/6i treatment in HR+/HER2- LABC/mBC. OS and DOR were only reported in two studies while other clinical endpoints (i.e., TTD, TTNT, TTP, ORR, CBR, and stable disease) were only reported in one study each. Similarly, safety and tolerability data were only reported in two studies each, and PROs were not reported in any study. This hindered our ability to provide a comprehensive assessment of real-world treatment effectiveness and safety following 1 L CDK4/6i treatment. The limited evidence may be due to the relatively short period of time that has elapsed since CDK4/6i first received US FDA approval for 1 L treatment of HR+/HER2- LABC/mBC (2015) [ 35 ]. As such, almost half of our evidence was informed by conference abstracts. Similarly, no real-world studies were identified in our review that reported outcomes for treatments in the third- or later-lines of therapy after 1 L CDK4/6i treatment. The lack of data in this patient population highlights a significant gap which limits our understanding of the effectiveness and safety for patients receiving later lines of therapy. As more patients receive CDK4/6i therapy in the 1 L setting, the number of patients requiring subsequent lines of therapy will continue to grow. Addressing this data gap over time will be critical to improve outcomes for patients with HR+/HER2- LABC/mBC following 1 L CDK4/6i therapy.

There are several strengths of this study, including adherence to the guidelines outlined in the Cochrane Handbook to ensure a standardized and reliable approach to the SLR [ 58 ] and reporting of the SLR following PRISMA guidelines to ensure transparency and reproducibility [ 59 ]. Furthermore, the inclusion of only RWE studies allowed us to assess the effectiveness of current standard of care treatments outside of a controlled environment and enabled us to identify an unmet need in this patient population.

This study had some notable limitations, including the lack of safety and additional effectiveness outcomes reported. In addition, the dearth of studies reporting PROs is a limitation, as PROs provide valuable insight into the patient experience and are an important aspect of assessing the impact of 2 L treatments on patients’ quality of life. The studies included in this review also lacked consistent reporting of clinical characteristics (e.g., menopausal status, sites of metastasis, prior surgery) making it challenging to draw comprehensive conclusions or comparisons based on these factors across the studies. Taken together, there exists an important gap in our understanding of the long-term management of patients with HR+/HER2- LABC/mBC. Additionally, the effectiveness results reported in our evidence base were informed by small sample sizes; many of the included studies reported median rwPFS based on less than 30 patients [ 39 , 40 , 41 , 46 , 49 , 51 , 60 ], with two studies not reporting the sample size at all [ 47 , 53 ]. This may impact the generalizability and robustness of the results. Relatedly, the SLR database search was conducted in December 2022; as such, novel agents (e.g., elacestrant and capivasertib + fulvestrant) that have since received FDA approval for the treatment of HR+/HER2- LABC/mBC may impact current 2 L rwPFS outcomes [ 61 , 62 ]. Finally, relative to the number of peer-reviewed full-text articles, this SLR identified eight abstracts and one poster presentation, comprising half (50%) of the included unique studies. As conference abstracts are inherently limited by how much content that can be described due to word limit constraints, this likely had implications on the present synthesis whereby we identified a dearth of real-world effectiveness outcomes in patients with HR+/HER2- LABC/mBC treated with 1 L CDK4/6i therapy.

Future research in this area should aim to address the limitations of the current literature and provide a more comprehensive understanding of optimal sequencing of effective and safe treatment for patients following 1 L CDK4/6i therapy. Specifically, future studies should strive to report robust data related to effectiveness, safety, and PROs for patients receiving 2 L treatment after 1 L CDK4/6i therapy. Future studies should also aim to understand the mechanism underlying CDK4/6i resistance. Addressing these gaps in knowledge may improve the long-term real-world management of patients with HR+/HER2- LABC/mBC. A future update of this synthesis may serve to capture a wider breadth of full-text, peer-reviewed articles to gain a more robust understanding of the safety, effectiveness, and real-world treatment patterns for patients with HR+/HER2- LABC/mBC. This SLR underscores the necessity for ongoing investigation and the development of innovative therapeutic approaches to address these gaps and improve patient outcomes.

This SLR qualitatively summarized the existing real-world effectiveness data for patients with HR+/HER2- LABC/mBC after 1 L CDK4/6i treatment. Results of this study highlight the limited available data and the suboptimal effectiveness of treatments employed in the 2 L setting and underscore the unmet need in this patient population. Additional studies reporting effectiveness and safety outcomes, in addition to PROs, for this patient population are necessary and should be the focus of future research.

PRISMA flow diagram. *Two included conference abstracts reported the same information as already included full-text reports, hence both conference abstracts were not identified as unique. Abbreviations: 1 L = first-line; AACR = American Association of Cancer Research; ASCO = American Society of Clinical Oncology; CDK4/6i = cyclin-dependent kinase 4/6 inhibitor; ESMO = European Society for Medical Oncology; ISPOR = Professional Society for Health Economics and Outcomes Research; n = number of studies; NMA = network meta-analysis; pts = participants; SABCS = San Antonio Breast Cancer Symposium; SLR = systematic literature review.

Number of studies reporting effectiveness outcomes exclusively for each treatment class. *Studies that lack sufficient information on effectiveness outcomes to classify based on the treatment classes outlined in the legend above. Abbreviations: CDK4/6i = cyclin-dependent kinase 4/6 inhibitor; ET = endocrine therapy; mTORi = mammalian target of rapamycin inhibitor.

Weighted average median rwPFS for 2 L treatments (recommended in ESMO/NCCN guidelines) after 1 L CDK4/6i treatment. Circular dot represents weighted average median across studies. Horizontal bars represent the range of values reported in these studies. Abbreviations: CDK4/6i = cyclin-dependent kinase 4/6 inhibitor; ESMO = European Society for Medical Oncology; ET = endocrine therapy, mTORi = mammalian target of rapamycin inhibitor; n = number of patients; NCCN = National Comprehensive Cancer Network; rwPFS = real-world progression-free survival.

Data availability

All data generated or analyzed during this study are included in this published article [and its supplementary information files]. This study is registered with PROSPERO (CRD42023383914).

Abbreviations

Second-line

Second-line treatment setting and beyond

American Association of Cancer Research

Aromatase inhibitor

American Society of Clinical Oncology

• Breast cancer

breast cancer gene/partner and localizer of BRCA2 positive

Clinical benefit rate

Cyclin-dependent kinase 4/6 inhibitor

Complete response

Duration of response

European Society for Medical Oncology

Food and Drug Administration

Human epidermal growth factor receptor 2

Human epidermal growth factor receptor 2 negative

Hormone receptor

Hormone receptor positive

Professional Society for Health Economics and Outcomes Research

Locally advanced breast cancer

Metastatic breast cancer

Medical Literature Analysis and Retrieval System Online

Medical subject headings

Mammalian target of rapamycin inhibitor

National Comprehensive Cancer Network

Newcastle Ottawa Scale

Objective response rate

Poly-ADP ribose polymerase inhibitor

Progression-free survival

Population, Intervention, Comparator, Outcome, Study Design

Partial response

Preferred Reporting Items for Systematic Literature Reviews and Meta-Analyses

Patient-reported outcomes

• Real-world evidence

San Antonio Breast Cancer Symposium

• Systematic literature review

Time-to-discontinuation

Time-to-next-treatment

Time-to-progression

United States

Łukasiewicz S, Czeczelewski M, Forma A, Baj J, Sitarz R, Stanisławek A, Breast, Cancer—Epidemiology. Risk factors, classification, prognostic markers, and current treatment Strategies—An. Updated Rev Cancers. 2021;13(17):4287.

Google Scholar  

World Health Organization (WHO). Breast Cancer Facts Sheet [updated July 12 2023. https://www.who.int/news-room/fact-sheets/detail/breast-cancer .

Arnold M, Morgan E, Rumgay H, Mafra A, Singh D, Laversanne M, et al. Current and future burden of breast cancer: global statistics for 2020 and 2040. Breast. 2022;66:15–23.

Article   PubMed   PubMed Central   Google Scholar  

Wilkinson L, Gathani T. Understanding breast cancer as a global health concern. Br J Radiol. 2022;95(1130):20211033.

Article   PubMed   Google Scholar  

Giaquinto AN, Sung H, Miller KD, Kramer JL, Newman LA, Minihan A et al. Breast Cancer Statistics, 2022. CA: A Cancer Journal for Clinicians. 2022;72(6):524– 41.

National Cancer Institute (NIH). Cancer Stat Facts: Female Breast Cancer [updated 2020. https://seer.cancer.gov/statfacts/html/breast.html .

American Cancer Society. Key Statistics for Breast Cancer [ https://www.cancer.org/cancer/types/breast-cancer/about/how-common-is-breast-cancer.html .

Zagami P, Carey LA. Triple negative breast cancer: pitfalls and progress. npj Breast Cancer. 2022;8(1):95.

Article   CAS   PubMed   PubMed Central   Google Scholar  

Matutino A, Joy AA, Brezden-Masley C, Chia S, Verma S. Hormone receptor-positive, HER2-negative metastatic breast cancer: redrawing the lines. Curr Oncol. 2018;25(Suppl 1):S131–41.

Lloyd MR, Wander SA, Hamilton E, Razavi P, Bardia A. Next-generation selective estrogen receptor degraders and other novel endocrine therapies for management of metastatic hormone receptor-positive breast cancer: current and emerging role. Ther Adv Med Oncol. 2022;14:17588359221113694.

Cardoso F, Senkus E, Costa A, Papadopoulos E, Aapro M, André F, et al. 4th ESO-ESMO International Consensus guidelines for advanced breast Cancer (ABC 4)†. Ann Oncol. 2018;29(8):1634–57.

Article   CAS   PubMed   Google Scholar  

US Food Drug Administration. Palbociclib (Ibrance) 2017 [updated March 31, 2017. https://www.fda.gov/drugs/resources-information-approved-drugs/palbociclib-ibrance .

US Food Drug Administration. FDA expands ribociclib indication in HR-positive, HER2-negative advanced or metastatic breast cancer 2018 [updated July 18. 2018. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-expands-ribociclib-indication-hr-positive-her2-negative-advanced-or-metastatic-breast-cancer .

US Food Drug Administration. FDA approves abemaciclib for HR positive, HER2-negative breast cancer 2017 [updated Sept 28. 2017. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-abemaciclib-hr-positive-her2-negative-breast-cancer .

NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®). Breast Cancer 2022 [ https://www.nccn.org/professionals/physician_gls/pdf/breast.pdf .

Gennari A, André F, Barrios CH, Cortés J, de Azambuja E, DeMichele A, et al. ESMO Clinical Practice Guideline for the diagnosis, staging and treatment of patients with metastatic breast cancer. Ann Oncol. 2021;32(12):1475–95.

Beaver JA, Amiri-Kordestani L, Charlab R, Chen W, Palmby T, Tilley A, et al. FDA approval: Palbociclib for the Treatment of Postmenopausal Patients with estrogen Receptor-Positive, HER2-Negative metastatic breast Cancer. Clin Cancer Res. 2015;21(21):4760–6.

US Food Drug Administration. Ribociclib (Kisqali) [ https://www.fda.gov/drugs/resources-information-approved-drugs/ribociclib-kisqali#:~:text=On%20March%2013%2C%202017%2C%20the,hormone%20receptor%20(HR)%2Dpositive%2C .

US Food Drug Administration. FDA approves new treatment for certain advanced or metastatic breast cancers [ https://www.fda.gov/news-events/press-announcements/fda-approves-new-treatment-certain-advanced-or-metastatic-breast-cancers .

US Food Drug Administration. FDA expands ribociclib indication in HR-positive, HER2-negative advanced or metastatic breast cancer. 2018 [ https://www.fda.gov/drugs/resources-information-approved-drugs/fda-expands-ribociclib-indication-hr-positive-her2-negative-advanced-or-metastatic-breast-cancer .

US Food Drug Administration. FDA approves abemaciclib as initial therapy for HR-positive, HER2-negative metastatic breast cancer [ https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-abemaciclib-initial-therapy-hr-positive-her2-negative-metastatic-breast-cancer .

Turner NC, Slamon DJ, Ro J, Bondarenko I, Im S-A, Masuda N, et al. Overall survival with Palbociclib and fulvestrant in advanced breast Cancer. N Engl J Med. 2018;379(20):1926–36.

Slamon DJ, Neven P, Chia S, Fasching PA, De Laurentiis M, Im SA, et al. Phase III randomized study of Ribociclib and Fulvestrant in hormone Receptor-Positive, human epidermal growth factor receptor 2-Negative advanced breast Cancer: MONALEESA-3. J Clin Oncol. 2018;36(24):2465–72.

Goetz MP, Toi M, Campone M, Sohn J, Paluch-Shimon S, Huober J, et al. MONARCH 3: Abemaciclib as initial therapy for advanced breast Cancer. J Clin Oncol. 2017;35(32):3638–46.

Gopalan PK, Villegas AG, Cao C, Pinder-Schenck M, Chiappori A, Hou W, et al. CDK4/6 inhibition stabilizes disease in patients with p16-null non-small cell lung cancer and is synergistic with mTOR inhibition. Oncotarget. 2018;9(100):37352–66.

Watt AC, Goel S. Cellular mechanisms underlying response and resistance to CDK4/6 inhibitors in the treatment of hormone receptor-positive breast cancer. Breast Cancer Res. 2022;24(1):17.

Goetz M. MONARCH 3: final overall survival results of abemaciclib plus a nonsteroidal aromatase inhibitor as first-line therapy for HR+, HER2- advanced breast cancer. SABCS; 2023.

Munzone E, Pagan E, Bagnardi V, Montagna E, Cancello G, Dellapasqua S, et al. Systematic review and meta-analysis of post-progression outcomes in ER+/HER2– metastatic breast cancer after CDK4/6 inhibitors within randomized clinical trials. ESMO Open. 2021;6(6):100332.

Gennari A, André F, Barrios CH, Cortés J, de Azambuja E, DeMichele A, et al. ESMO Clinical Practice Guideline for the diagnosis, staging and treatment of patients with metastatic breast cancer. Annals of Oncology. 2021;32(12):1475-95.

European Society for Medical Oncology (ESMO). ESMO ​Metastatic Breast Cancer Living Guideline: ER-positive HER2-negative​ Breast Cancer​ [updated May 2023. https://www.esmo.org/living-guidelines/esmo-metastatic-breast-cancer-living-guideline/er-positive-her2-negative-breast-cancer .

Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Welch PM VA, editors. Cochrane Handbook for Systematic Reviews of Interventions version 6.2 (updated February 2021). www.training.cochrane.org/handbook : Cochrane; 2021.

Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. PLoS Med. 2021;18(3):e1003583.

McGowan J, Sampson M, Salzwedel DM, Cogo E, Foerster V, Lefebvre C. PRESS peer review of electronic search strategies: 2015 Guideline Statement. J Clin Epidemiol. 2016;75:40–6.

Fraser C, Murray A, Burr J. Identifying observational studies of surgical interventions in MEDLINE and EMBASE. BMC Med Res Methodol. 2006;6(1):41.

US Food Drug Administration. Palbociclib (Ibrance). Silver Spring, MD: US Food and Drug Administration; 2017.

Book   Google Scholar  

GA Wells BS, D O’Connell J, Peterson V, Welch M, Losos PT. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses [ https://www.ohri.ca/programs/clinical_epidemiology/oxford.asp .

Lo CK-L, Mertz D, Loeb M. Newcastle-Ottawa Scale: comparing reviewers’ to authors’ assessments. BMC Med Res Methodol. 2014;14(1):45.

Martin JM, Handorf EA, Montero AJ, Goldstein LJ. Systemic therapies following progression on first-line CDK4/6-inhibitor treatment: analysis of real-world data. Oncologist. 2022;27(6):441–6.

Kalinsky KM, Kruse M, Smyth EN, Guimaraes CM, Gautam S, Nisbett AR et al. Abstract P1-18-37: Treatment patterns and outcomes associated with sequential and non-sequential use of CDK4 and 6i for HR+, HER2- MBC in the real world. Cancer Research. 2022;82(4_Supplement):P1-18-37-P1-18-37.

Choong GM, Liddell S, Ferre RAL, O’Sullivan CC, Ruddy KJ, Haddad TC, et al. Clinical management of metastatic hormone receptor-positive, HER2-negative breast cancer (MBC) after CDK 4/6 inhibitors: a retrospective single-institution study. Breast Cancer Res Treat. 2022;196(1):229–37.

Xi J, Oza A, Thomas S, Ademuyiwa F, Weilbaecher K, Suresh R, et al. Retrospective Analysis of Treatment Patterns and effectiveness of Palbociclib and subsequent regimens in metastatic breast Cancer. J Natl Compr Canc Netw. 2019;17(2):141–7.

Rozenblit M, Mun S, Soulos P, Adelson K, Pusztai L, Mougalian S. Patterns of treatment with everolimus exemestane in hormone receptor-positive HER2-negative metastatic breast cancer in the era of targeted therapy. Breast Cancer Res. 2021;23(1):14.

Bashour SI, Doostan I, Keyomarsi K, Valero V, Ueno NT, Brown PH, et al. Rapid breast Cancer Disease Progression following cyclin dependent kinase 4 and 6 inhibitor discontinuation. J Cancer. 2017;8(11):2004–9.

Giridhar KV, Choong GM, Leon-Ferre R, O’Sullivan CC, Ruddy K, Haddad T, et al. Abstract P6-18-09: clinical management of metastatic breast cancer (MBC) after CDK 4/6 inhibitors: a retrospective single-institution study. Cancer Res. 2019;79:P6–18.

Article   Google Scholar  

Mougalian SS, Feinberg BA, Wang E, Alexis K, Chatterjee D, Knoth RL, et al. Observational study of clinical outcomes of eribulin mesylate in metastatic breast cancer after cyclin-dependent kinase 4/6 inhibitor therapy. Future Oncol. 2019;15(34):3935–44.

Moscetti LML, Riggi L, Sperduti I, Piacentini FOC, Toss A, Barbieri E, Cortesi L, Canino FMA, Zoppoli G, Frassoldati A, Schirone A, Dominici MECF. SEQUENCE OF TREATMENTS AFTER CDK4/6 THERAPY IN ADVANCED BREAST CANCER (ABC), A GOIRC MULTICENTER RETRO/ PROSPECTIVE STUDY. PRELIMINARY RESULTS IN THE RETROSPECTIVE SERIES OF 116 PATIENTS. Tumori. 2022;108(4S):80.

Menichetti AZE, Giorgi CA, Bottosso M, Leporati R, Giarratano T, Barbieri C, Ligorio F, Mioranza E, Miglietta F, Lobefaro R, Faggioni G, Falci C, Vernaci G, Di Liso E, Girardi F, Griguolo G, Vernieri C, Guarneri V, Dieci MV. CDK 4/6 INHIBITORS FOR METASTATIC BREAST CANCER: A MULTICENTER REALWORLD STUDY. Tumori. 2022;108(4S):70.

Marschner NW, Harbeck N, Thill M, Stickeler E, Zaiss M, Nusch A, et al. 232P Second-line therapies of patients with early progression under CDK4/6-inhibitor in first-line– data from the registry platform OPAL. Annals of Oncology. 2022;33:S643-S4

Gousis C, Lowe KMH, Kapiris M. V. Angelis. Beyond First Line CDK4/6 Inhibitors (CDK4/6i) and Aromatase Inhibitors (AI) in Patients with Oestrogen Receptor Positive Metastatic Breast Cancer (ERD MBC): The Guy’s Cancer Centre Experience. Clinical Oncology2022. p. e178.

Endo Y, Yoshimura A, Sawaki M, Hattori M, Kotani H, Kataoka A, et al. Time to chemotherapy for patients with estrogen receptor-positive breast Cancer and cyclin-dependent kinase 4 and 6 inhibitor use. J Breast Cancer. 2022;25(4):296–306.

Li Y, Li W, Gong C, Zheng Y, Ouyang Q, Xie N, et al. A multicenter analysis of treatment patterns and clinical outcomes of subsequent therapies after progression on palbociclib in HR+/HER2- metastatic breast cancer. Ther Adv Med Oncol. 2021;13:17588359211022890.

Amaro CP, Batra A, Lupichuk S. First-line treatment with a cyclin-dependent kinase 4/6 inhibitor plus an aromatase inhibitor for metastatic breast Cancer in Alberta. Curr Oncol. 2021;28(3):2270–80.

Crocetti SPM, Tassone L, Marcantognini G, Bastianelli L, Della Mora A, Merloni F, Cantini L, Scortichini L, Agostinelli V, Ballatore Z, Savini A, Maccaroni E. Berardi R. What is the best therapeutic sequence for ER-Positive/HER2- Negative metastatic breast cancer in the era of CDK4/6 inhibitors? A single center experience. Tumori. 2020;106(2S).

Nichetti F, Marra A, Giorgi CA, Randon G, Scagnoli S, De Angelis C, et al. 337P Efficacy of everolimus plus exemestane in CDK 4/6 inhibitors-pretreated or naïve HR-positive/HER2-negative breast cancer patients: A secondary analysis of the EVERMET study. Annals of Oncology. 2020;31:S382

Luhn P, O’Hear C, Ton T, Sanglier T, Hsieh A, Oliveri D, et al. Abstract P4-13-08: time to treatment discontinuation of second-line fulvestrant monotherapy for HR+/HER2– metastatic breast cancer in the real-world setting. Cancer Res. 2019;79(4Supplement):P4–13.

Mittal A, Molto Valiente C, Tamimi F, Schlam I, Sammons S, Tolaney SM et al. Filling the gap after CDK4/6 inhibitors: Novel Endocrine and Biologic Treatment options for metastatic hormone receptor positive breast Cancer. Cancers (Basel). 2023;15(7).

Ashai N, Swain SM. Post-CDK 4/6 inhibitor therapy: current agents and novel targets. Cancers (Basel). 2023;15(6).

Higgins JPTTJ, Chandler J, Cumpston M, Li T, Page MJ, Welch VA, editors. Cochrane Handbook for Systematic Reviews of Interventions version 6.3 (updated February 2022). www.training.cochrane.org/handbook : Cochrane; 2022.

Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71.

Serdar CC, Cihan M, Yücel D, Serdar MA. Sample size, power and effect size revisited: simplified and practical approaches in pre-clinical, clinical and laboratory studies. Biochem Med (Zagreb). 2021;31(1):010502.

US Food Drug Administration. FDA approves elacestrant for ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer [updated January 27 2023. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-elacestrant-er-positive-her2-negative-esr1-mutated-advanced-or-metastatic-breast-cancer .

US Food Drug Administration. FDA approves capivasertib with fulvestrant for breast cancer [updated November 16 2023. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-capivasertib-fulvestrant-breast-cancer .

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Acknowledgements

The authors would like to acknowledge Joanna Bielecki who developed, conducted, and documented the database searches.

This study was funded by Pfizer Inc. (New York, NY, USA) and Arvinas (New Haven, CT, USA).

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Sarah Kane, Belal Howidi, Bao-Ngoc Nguyen and Imtiaz A. Samjoo contributed equally to this work.

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Veronique Lambert & Yan Wu

EVERSANA, Burlington, ON, Canada

Sarah Kane, Belal Howidi, Bao-Ngoc Nguyen & Imtiaz A. Samjoo

Arvinas, 06511, New Haven, CT, USA

David Chandiwana & Michelle Edwards

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VL, IAS, SK, BH, BN, DC, YW, and ME participated in the conception and design of the study. IAS, SK, BH and BN contributed to the literature review, data collection, analysis, and interpretation of the data. VL, IAS, SK, BH, BN, DC, YW, and ME contributed to the interpretation of the data and critically reviewed for the importance of intellectual content for the work. VL, IAS, SK, BH, BN, DC, YW, and ME were responsible for drafting or reviewing the manuscript and for providing final approval. VL, IAS, SK, BH, BN, DC, YW, and ME meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship for this article, take responsibility for the integrity of the work, and have given their approval for this version to be published.

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The authors of this manuscript declare that the research presented was funded by Pfizer Inc. and Arvinas. While the support from Pfizer Inc. and Arvinas was instrumental in facilitating this research, the authors affirm that their interpretation of the data and the content of this manuscript were conducted independently and without bias to maintain the transparency and integrity of the research. IAS, SK, BH, and BN are employees of EVERSANA, Canada, which was a paid consultant to Pfizer in connection with the development of this manuscript.

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Lambert, V., Kane, S., Howidi, B. et al. Systematic literature review of real-world evidence for treatments in HR+/HER2- second-line LABC/mBC after first-line treatment with CDK4/6i. BMC Cancer 24 , 631 (2024). https://doi.org/10.1186/s12885-024-12269-8

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Received : 26 January 2024

Accepted : 16 April 2024

Published : 23 May 2024

DOI : https://doi.org/10.1186/s12885-024-12269-8

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