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 cancer. We aimed to assess the potential of tubal ligation in reducing the risk 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 USA, and the UK who had undergone genetic testing and who carried a pathogenic mutation in BRCA1 or BRCA2. Cases were 232 women with a history of invasive ovarian cancer, and controls were 232 women without ovarian cancer, and who had both ovaries intact. Cases and controls were matched for year of birth, country of residence, and mutation (BRCA1 or BRCA2). The odds ratio for developing ovarian cancer was estimated for tubal ligation, adjusting for oral contraceptive use, parity, history of breast cancer, and ethnic group.


RESULTS
In an unadjusted analysis among BRCA1 carriers, significantly fewer 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 group, the odds ratio was 0.39 (p=0.002). Combination of tubal ligation and past 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.


CONCLUSIONS
Tubal ligation is a feasible option to reduce the risk of ovarian cancer in women with BRCA1 mutations who have completed childbearing.
Narod
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SA
Centre for Research on Women's Health, University of Toronto, 790 Bay Street, Room 750, M5G 1N8, Ontario, Canada. steven.narod@swchsc.on.ca
Sun
P
P
Ghadirian
P
P
Lynch
H
H
Isaacs
C
C
Garber
J
J
Weber
B
B
Karlan
B
B
Fishman
D
D
Rosen
B
B
Tung
N
N
Neuhausen
S L
SL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019313:BRCA1 Protein / Q000235:genetics*; D024682:BRCA2 Protein; D001943:Breast Neoplasms / Q000235:genetics / Q000517:prevention & control; D005260:Female; D006580:Genetic Carrier Screening; D006801:Humans; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D009363:Neoplasm Proteins / Q000235:genetics*; D016017:Odds Ratio; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000517:prevention & control; D012307:Risk Factors; D013246:Sterilization, Tubal; D014157:Transcription Factors / Q000235:genetics*
D019313:BRCA1 Protein; D024682:BRCA2 Protein; D009363:Neoplasm Proteins; D014157:Transcription Factors