Potential for Bias in Studies on Efficacy of Prophylactic Surgery for BRCA1 and BRCA2 Mutation

Abstract

Women who carry a germline mutation in the BRCA1 or BRCA2 (BRCA1/2) gene have a 50%–80% lifetime risk of developing breast cancer and a 10%–40% lifetime risk of developing ovarian cancer (1–4). These high-risk women are being offered various preventive measures, including surveillance, chemoprevention, and prophylactic surgery to reduce their risk of cancer. During a prophylactic bilateral mastectomy or a prophylactic bilateral salpingo-oophorectomy, healthy breast or ovarian tissue, respectively, is removed to prevent the development of a malignancy. However, these procedures do not completely eradicate cancer risk because, often, not all tissue at risk is taken away (5–9). Because of the invasive and irreversible nature of prophylactic surgery, knowledge of its efficacy and the extent of risk reduction are crucial for women considering the procedure.