BRCA testing patterns in breast cancer over time in the United States: challenges and opportunities for improvement

Testing for germline mutations in breast cancer genes (gBRCAm) is recommended to inform treatment decisions for patients with breast cancer (BC); however, not all eligible patients will undergo testing. This targeted literature review summarizes evidence on real-world patterns of gBRCAm testing in BC in the United States (US) and misconceptions, beliefs, attitudes, or barriers related to gBRCAm testing. A total of 35 publications published up to September 2024 were included in the review, representing 32 unique studies. Since the early 2000's, studies consistently reported increases in BRCA testing over time (7%-47% increase, with variations based on differing study designs, populations, and assessment periods). However, an unmet need for improved testing remains, particularly for eligible patients with hormone receptor-positive early BC. Barriers to testing reported by patients and physicians include lack of clear guidelines around gBRCAm testing eligibility, high costs, and inadequate insurance coverage. Additionally, patients with BC often reported limited knowledge regarding gBRCAm testing. Variable access to genetic counseling was reported by physicians as both a driver and a barrier to testing, and some physicians lack the expertise or confidence to discuss testing results with patients. Further evaluation on recent gBRCAm testing trends and barriers related to BRCA testing in the US is needed as the majority of studies identified in this literature review had data collection periods that occurred prior to 2020.