BACKGROUND: This study quantified patients’ benefit-risk preferences for attributes associated with human epidermal growth factor receptor 2 (HER2)–targeted treatments for breast cancer (BC) and estimated the minimum acceptable benefit (MAB) as perceived by patients in terms of additional months of progression-free survival (PFS) for given treatment-related adverse events (AEs).
METHODS: We conducted an online discrete-choice experiment (DCE) among patients with self-reported advanced or metastatic BC in the United States (N = 200). Respondents answered nine DCE questions. Each question offered a choice between two hypothetical treatment profiles created by an experimental design, defined by six attributes with varying levels, based on available data for approved and investigational therapies: PFS, nausea and vomiting, diarrhea, liver function problems, risk of heart failure, and risk of serious lung damage and infections. Data were analyzed using a random-parameters logit model, and results were used to calculate the MAB as additional months of PFS required to offset worse levels of AEs. We tested for differences in preferences between subgroups for stage III or stage IV BC and HER2 positive or negative status.
RESULTS: Mean patient age was 49 years, 68% had stage IV BC, and 44% were HER2 positive. Patients placed the most importance on a change in PFS from 5 months to 26 months, while change from no diarrhea to severe diarrhea had the least relative importance. Avoiding a 15% risk of heart failure had the largest MAB in additional months of PFS (5.3 months), followed by avoiding a 15% risk of serious lung damage and infections (4.6 months), possible severe liver function problems (4.2 months), severe nausea and vomiting (4.0 months) and severe diarrhea (2.7 months) compared with having none of the AEs. Women with stage IV BC placed more relative importance on 21 additional months of PFS (from 5 months to 26 months) over avoiding AEs compared with women with stage III BC. No differences based on HER2 status were observed.
CONCLUSIONS: In this study, patients valued PFS gain higher than the potential risk of AEs when deciding between BC treatments. The importance of PFS increased for women with stage IV BC.
