Differences in Preferences for Drug Therapy Between Patients with Metastatic Versus Early-Stage Breast Cancer: A Systematic Literature Review

IntroductionCompared with early stages (eBC) metastatic BC (mBC) is incurable. In mBC, aggressive treatment may increase the duration of survival but may also cause severe treatment side effects. A better understanding how patients with BC value different aspects of drug therapy might improve treatment effectiveness, satisfaction and adherence. This systematic review aims to identify and summarise studies evaluating patient preferences for drug therapy of BC and to compare preferences of patients with eBC and mBC.MethodsThe systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The electronic databases PubMed and Web of Science were searched on 22 June 2023. All studies published to this point were considered. Original studies reporting patient preferences on BC drug therapy determined by any type of choice experiment were eligible. A narrative synthesis of the effect measures presented as relative importance ratings, trade-offs (required benefit to make a therapy worthwhile) or monetary values of the treatment attributes was reported for each study. Risk of bias assessment for individual studies was performed using the checklist for observational studies from the STROBE Statement and the checklist from 'Conducting Discrete Choice Experiments to Inform Healthcare Decision Making: A User's Guide'. The study protocol was registered at the PROSPERO database (CRD42022377031).ResultsA total of 34 studies met the inclusion criteria were included in the analysis evaluating the preferences of patients with eBC (n = 18), mBC (n = 10) or any stage BC (n = 6) on, for example, chemotherapy, endocrine therapy, hormonal therapy or CKD4/6-inhibitors using different types of choice experiments. Regardless of the stage, most patients valued treatment effectiveness in terms of survival gains higher than potential adverse drug reactions (ADRs). Treatment cost, mode of administration, treatment regimen and monitoring aspects were considered as least important treatment attributes. In addition, preferences concerning 16 different types of ADRs were described, showing high heterogeneity within BC stages. Yet, comparable results across BC stages were observed.ConclusionsRegardless of the stage, patients with BC consistently valued survival gains as the most important attribute and were willing to accept the risk of potential ADRs. Incorporating patient preferences in shared decision making may improve the effectiveness of interventions by enhancing adherence to drug therapy in patients suffering from BC. Preferences of patients with breast cancer for drug therapy play a crucial role in treatment efficacy, satisfaction and adherence. In this systematic review following the PRISMA guidelines, 34 studies were analysed to determine patient preferences at different stages of breast cancer, comparing early stage and metastatic disease. Regardless of stage, patients with breast cancer consistently prioritised survival benefit as the most important treatment feature. This universal emphasis on survival held true even in the face of potential side effects, with patients willing to accept the associated risks. Conversely, factors unrelated to efficacy, such as the cost of treatment, route of administration, characteristics of the treatment regimen and monitoring aspects, were considered less important in treatment decisions. The study revealed a nuanced landscape of patient preferences, with greater variation within breast cancer stages than between them. While survival remained an unwavering priority, the variability in expressed preferences emphasises the individual nature of patient perspectives. In conclusion, incorporating patient preferences, particularly those that emphasise the importance of survival, into shared decision-making processes is a critical factor in improving treatment adherence. This patient-centred approach is likely to improve the overall effectiveness of breast cancer treatment and highlights the need for tailored strategies that take into account the individual preferences of patients at different stages of the disease.