Risk for breast and ovarian cancer modified by the use of oral contraceptives in BRCA1/2 mutation carriers
Huber D.1, Seitz S.1, Kast K.2, Emons G.3, Ortmann O.1
1University Medical Center Regensburg, Department of Gynecology and Obstetrics, Regensburg, Deutschland, 2Medical Faculty and University Hospital Carl Gustav Carus, TU Dresden, Department of Gynecology and Obstetrics, Dresden, Deutschland, 3Georg August University Göttingen, Department of Gynecology and Obstetrics, Göttingen, Deutschland

Purpose: Oral contraception (OC) is known to increase breast cancer and reduce ovarian cancer risk in the general population. BRCA mutation carriers have an increased risk for breast or ovarian cancer. We analysed the published data on the safety of OC in BRCA mutation carriers.
Methods: All relevant articles published in English from 1995 to 2018 were revised. Literature was identified through a search on Pubmed and Cochrane Library.
Results: Four metaanalyses, one review, one case-control-study, two case-only studies, one prospective and one retrospective cohort study on the association between OC use and breast cancer in BRCA mutation carriers were identified. Some studies report a risk elevation, while others did not find an association. Other studies report an association limited to early-onset breast cancer and/or associated with young age at first start of OC. We also found four metaanalyses, one review, one case-control and one retrospective cohort study on OC and ovarian cancer risk in BRCA mutation carriers. All report a risk reduction for ever OC users, and several describe an inverse correlation with duration of use.
Conclusion: OC leads to a risk reduction of ovarian cancer also in BRCA mutation carriers. However, an increase in breast cancer risk due to OC cannot be excluded. Therefore, women with BRCA mutation who consider OC use must be informed about possible increases in breast cancer risk and alternative contraceptive methods. OC should not be used for the prevention of ovarian cancer in this population due to the possibly increased breast cancer risk.