Use of Exogenous Hormones and Risks of Breast and Ovarian Cancers in BRCA1/2 Mutation Carriers; Methodological and Clinical Considerations

Risks of breast and ovarian cancer among BRCA1/2 mutation carriers are high, even for the young. Recommendations for use of exogenous hormones designed for BRCA1/2 mutation carriers may therefore be appropriate. Here we review studies on the associations between oral contraceptives (OC) and hormone-replacement therapy (HRT) use and the risks of breast or ovarian cancer among BRCA1/2 carriers. Almost all studies had a retrospective design. OC use reduced the risk of ovarian cancer, but high uptake of bilateral prophylactic oophorectomy (BPO) renders this protective association hardly relevant for most BRCA1/2 mutation carriers. As long as a positive association between OC use and breast cancer risk cannot be ruled out, it may be necessary to consider alternative methods of contraception. Evidence on HRT is scarce. Assuming similar associations for BRCA1/2 carriers as for the general population it may be advisable to use HRT for a short period only.