Reproductive risk factors for ovarian cancer in carriers of BRCA1 or BRCA2 mutations: A case-control study Journal Article


Authors: McLaughlin, J. R.; Risch, H. A.; Lubinski, J.; Möller, P.; Ghadirian, P.; Lynch, H.; Karlan, B.; Fishman, D.; Rosen, B.; Neuhausen, S. L.; Offit, K.; Kauff, N.; Domchek, S.; Tung, N.; Friedman, E.; Foulkes, W.; Sun, P.; Narod, S. A.
Article Title: Reproductive risk factors for ovarian cancer in carriers of BRCA1 or BRCA2 mutations: A case-control study
Abstract: Background: Several of the known risk factors for ovarian cancer are thought to act through their effects on ovulation and the menstrual cycle, such as parity, breastfeeding, and use of oral contraceptives. We aimed to assess the effect of these three risk factors, and of tubal ligation, on the risk of ovarian cancer in women who carry a mutation in the BRCA1 or BRCA2 genes. Methods: We did a matched case-control study in women who were found to carry a pathogenetic mutation in BRCA1 or BRCA2. Participants were derived from a population-based study of ovarian cancer in Ontario, Canada, and from an international registry of mutation carriers based in Toronto, ON, Canada. All participants completed a written questionnaire that detailed their reproductive history. Women with invasive ovarian cancer and controls were matched on year of birth, country of residence, mutation (BRCA1 or BRCA2), and history of breast cancer. The odds ratios and 95% CI for ovarian cancer were estimated with respect to use of oral contraceptives, parity, breastfeeding, and tubal ligation. Findings: Questionnaires were completed by 799 women with a history of invasive ovarian cancer (670 with BRCA1 mutations, 128 with BRCA2 mutations, and one with a mutation in both genes), and controls were 2424 women without ovarian cancer (2043 with BRCA1 mutations, 380 with BRCA2 mutations, and one with a mutation in both genes). Use of oral contraceptives reduced the risk of ovarian cancer in carriers of BRCA1 mutations (odds ratio 0·56 [95% CI 0·45-0·71]; p<0·0001) and carriers of BRCA2 mutations (0·39 [0·23-0·66]; p=0·0004). Parity was associated with a reduced risk for carriers of BRCA1 mutations (0·67 [0·46-0·96]; p=0·03), but with an increased risk for those with BRCA2 mutations (2·74 [1·18-6·41]; p=0·02). Breastfeeding was associated with a reduced risk for carriers of BRCA1 mutations (0·74 [0·56-0·97]; p=0·03). An effect of similar magnitude was seen for carriers of BRCA2 mutations (0·72 [0·41-1·29]; p=0·27), but this was not statistically significant. The association with tubal ligation was not significant for carriers of BRCA1 mutations (0·80 [0·59-1·08]; p=0·15), or for carriers of BRCA2 mutations (0·63 [0·34-1·15]; p=0·13). Interpretation: Oral contraceptives could be used as a means to prevent ovarian cancer in carriers of BRCA1 and BRCA2 mutations. The possible adverse effect of parity on ovarian-cancer risk in women with a BRCA2 mutation needs further study. © 2007 Elsevier Ltd. All rights reserved.
Keywords: adult; controlled study; aged; aged, 80 and over; middle aged; major clinical study; mutation; case-control studies; anamnesis; cancer risk; ovarian neoplasms; ovary cancer; risk factors; mutational analysis; breast neoplasms; brca1 protein; brca2 protein; heterozygote; time factors; risk assessment; carcinogenesis; cancer invasion; confidence interval; questionnaire; statistical significance; risk reduction; age of onset; canada; oral contraceptive agent; oral contraception; matched-pair analysis; population based case control study; parity; breast feeding; uterine tube ligation; contraceptives, oral, hormonal
Journal Title: Lancet Oncology
Volume: 8
Issue: 1
ISSN: 1470-2045
Publisher: Elsevier Science, Inc.  
Date Published: 2007-01-01
Start Page: 26
End Page: 34
Language: English
DOI: 10.1016/s1470-2045(06)70983-4
PUBMED: 17196508
PROVIDER: scopus
DOI/URL:
Notes: --- - "Cited By (since 1996): 66" - "Export Date: 17 November 2011" - "CODEN: LOANB" - "Source: Scopus"
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  1. Kenneth Offit
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  2. Noah Kauff
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