Bilateral prophylactic oophorectomy and bilateral prophylactic mastectomy in a prospective cohort of unaffected BRCA1 and BRCA2 mutation carriers

Background: Women with BRCA1 or BRCA2 (BRCA1/2) mutations can reduce cancer incidence and mortality by using bilateral prophylactic oophorectomy (BPO) or bilateral prophylactic mastectomy (BPM). The availability of these risk-reduction strategies is an important consideration in the decision to undergo genetic testing. Patients and Methods: We evaluated the use of BPO and BPM in a prospective sample of 537 female BRCA1/2 mutation carriers from 17 centers in North America and Europe. These women were aged > 30 years, had no BPM, BPO, breast cancer, or ovarian cancer before the disclosure of their genetic test results and were followed for ≥ 6 months. Results: Bilateral prophylactic oophorectomy is used significantly more frequently than BPM (55% vs. 21%; P < .001). Bilateral prophylactic oophorectomy was more common among women age ≥ 40 years compared with women aged < 40 years (68% vs. 43%; P < .001) and among parous women compared with nulliparous women (60% vs. 39%; P < .001). There was no difference in BPM (P = .83) or BPO (P = .09) in BRCA1 versus BRCA2 carriers. Multivariate models identified age and parity as a predictor of BPO in BRCA1 carriers; age and ovarian cancer family history in BRCA2 carriers; parity and ovarian cancer family history as a predictor of BPM in BRCA1 carriers; and smoking and ovarian cancer family history in BRCA2 carriers. Conclusion: Bilateral prophylactic oophorectomy is more commonly used than BPM in unaffected BRCA1/2 mutation carriers. Parity, age, and family history can also influence BPO and BPM uptake. Consistent with current recommendations, BPO is used by the majority of parous women aged > 40 years.