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.

[INTRODUCTION] Poly(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.

[METHODS] We 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.

[RESULTS] Among 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.

[CONCLUSIONS] Individuals 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.