Tubal ligation and risk of ovarian cancer in carriers of BRCA1 or BRCA2 mutations: a case-control study

Background In several case-control and prospective studies, tubal ligation has been associated with a decreased risk of invasive epithelial ovarian ca ncer. We aimed to assess the potential of tubal ligation in reducing the ri sk of ovarian cancer in women who carry predisposing mutations in the BRCA1 or BRCA2 genes. Methods We did a matched case-control study among women from Canada, the US A, and the UK who had undergone genetic testing and who carried a pathogeni c mutation in BRCA1 or BRCA2. Cases were 232 women with a history of invasi ve ovarian cancer, and controls were 232 women without ovarian cancer, and who had both ovaries intact. Cases and controls were matched for year of bi rth, country of residence, and mutation (BRCA1 or BRCA2). The odds ratio fo r developing ovarian cancer was estimated for tubal ligation, adjusting for oral contraceptive use, parity, history of breast cancer, and ethnic group . Findings In an unadjusted analysis among BRCA1 carriers, significantly fewe r cases than controls had ever had tubal ligation (30 of 173 [18%] vs 60 of 173 [35%], odds ratio 0.37 [95% CI 0.21-0.63]; p=0.0003). After adjustment for oral contraceptive use, parity, history of breast cancer and ethnic gr oup, the odds ratio was 0.39 (p=0.002). Combination of tubal ligation and p ast use of an oral contraceptive was associated with an odds ratio of 0.28 (0.15-0.52). No protective effect of tubal ligation was seen among carriers of the BRCA2 mutation. Interpretation Tubal ligation is a feasible option to reduce the risk of ov arian cancer in women with BRCA1 mutations who have completed childbearing.