Prevalence and predictive testing preferences for breast cancer treatment side effects.

INTRODUCTION: Women undergoing breast cancer (BC) treatment often face side effects that impact their quality of life and adherence. Biomarker tests to predict side effects could improve treatment options and adherence. This study assessed the prevalence of common side effects and women's preferences for biomarker testing. METHODS: Data from surveys of patients with BC at University Hospitals Cleveland Medical Center (UHCMC; N = 586) and Penn State Cancer Institute (PSCI; N = 562) were analyzed using descriptive statistics, chi-square, and Mann-Whitney U. RESULTS: In the UHCMC and PSCI cohorts, 53.2% and 60.2% of the women prescribed endocrine therapy experienced joint and musculoskeletal pain (JMSP), respectively, with approximately one third discontinuing or changing treatment for BC. JMSP was associated with a higher mean body mass index (BMI). Over half of the women experienced hot flashes which were associated with younger age and Black race. Of the women receiving chemotherapy, nearly two thirds experienced neuropathy. Approximately one quarter of the respondents reported lymphedema, which as associated with a higher mean BMI, chemotherapy, and Black race. Quality of life was negatively impacted by side effects. Most women who experienced a side effect were more likely to prefer having a predictive test with the exception of women who experienced taxane-induced peripheral neuropathy. CONCLUSION: Side effects from BC treatment negatively affect quality of life and could be mitigated if their likelihood was known. Since the majority of BC patients view predictive biomarker testing favorably, future work focusing on treatment side effects is crucial to improve adherence, particularly to endocrine therapy.