Risk-reducing salpingo-oophorectomy and breast cancer incidence among Jewish BRCA1/BRCA2-mutation carriers - an Israeli matched pair study.

OBJECTIVE: To study the association of risk-reducing bilateral salpingo-oophorectomy (RRBSO) and breast cancer risk among BRCA pathogenic sequence variants (PSV).

METHODS: Jewish Israeli BRCA-carriers who underwent RRBSO were matched with those who did not - by the mutated gene and year of birth (±1 year). Breast cancer rates were compared.

RESULTS: Overall, 127 pairs met inclusion criteria, 79 (60.6%) pairs harbored BRCA1-PSV and 50 (39.4%) pairs - BRCA2-PSV. Median follow-up was 8.7 years [interquartile range 4.6-16.1 years]. Breast cancer rate for all BRCA-carriers combined was not affected by RRBSO [RRBSO 21 (16.5%) vs. no RRBSO 31(24.4%), Hazard ration (HR) for breast cancer 0.61, 95% CI 0.33-1.14, p=0.127]. No association between RRBSO and breast cancer incidence was noted among BRCA1-PSV carriers. In BRCA2-PSV carriers, RRBSO was associated with a decreased overall breast cancer incidence (HR=0.20, 95% CI 0.44-0.91, p=0.038), as well as after 5, 10,15 and 20 years. Hormone replacement therapy (HRT) was used by 62 PSV-carriers, 52 in the RRBSO group and 10 in the no-RRBSO group and did not affect breast cancer risk (p=0.463).

CONCLUSION: RRBSO is associated with breast cancer risk reduction in Jewish Israeli BRCA2 PSV-carriers.