Factors influencing Patient Preferences for BRCA Testing and Adjuvant Therapy in HER2-Negative Early Breast Cancer in the United States: Best-Worst Scaling and Discrete Choice Experiment.

introductionPoly(ADP-ribose) polymerase inhibitors (PARPi) have survival benefits for patients with high-risk (High-risk disease is defined per the phase III OlympiA trial as follows: for triple-negative breast cancer, residual disease after neoadjuvant chemotherapy or node-positive or ≥ 2 cm tumors after adjuvant chemotherapy; for hormone receptor-positive disease, four or more positive nodes after adjuvant chemotherapy or a CPS + EG score ≥ 3 after incomplete response to neoadjuvant chemotherapy. The CPS + EG score accounts for clinical/pathologic stage, ER status, and grade (Giaquinto et al. in CA Cancer J Clin 72:524-541, 2022)), human epidermal growth factor receptor 2 (HER2)-negative early breast cancer (eBC) with germline BReast CAncer gene mutations (gBRCAm). However, many patients are unaware of their gBRCA status; this can impact eligibility for targeted treatment. We sought to evaluate patient preferences for BRCA testing and treatment decision-making as they relate to HER2-negative eBC.

methodsWe conducted an online survey, including a best-worst scaling exercise (BWS) and discrete-choice experiment (DCE), among patients with self-reported HER2-negative eBC residing in the USA who were either untested, unsure if they were tested, or tested positive for the gBRCAm. The BWS generated a rank ordering of 16 barriers and facilitators to BRCA testing. The DCE evaluated patient preferences for adjuvant therapies versus no treatment based on seven treatment attributes: invasive disease-free survival, targeted treatment, nausea risk, risk of serious side effects, regimen, treatment duration, and cost. BWS and DCE exercises were analyzed using hierarchical Bayesian models.

resultsAmong the 359 women included in our sample, the top facilitators for BRCA testing were determining eligibility for targeted therapy that may prevent or delay metastasis, a physician's recommendation, and absence of out-of-pocket costs (OOPC). In contrast, the top barriers were an OOPC of $250, potential anxiety from test results, and the possibility of a 3- to 4-week delay in treatment. The DCE showed that most participants preferred adjuvant treatment (77.6%) over no treatment, and reducing treatment OOPC from $900 to $0, reducing the risk of serious side effects from 77 to 24%, and having a BRCA-targeted treatment influenced treatment choice most.

conclusionsIndividuals reported that a key benefit of BRCA testing was the insight it provided into their treatment options, allowing for more personalized care. However, OOPC was a barrier to testing. Their choice to receive adjuvant therapy was most influenced by OOPC, followed by the tolerability of the treatment and the ability to receive a targeted therapy.