BRCA1 and breast cancer: Individuals with BRCA1 or BRCA2 variants have an increased baseline risk of breast cancer, and the additive impact of combined oral contraceptive risks would be magnified.89,90 Current and recent use of estrogen-containing hormonal contraception is thought to increase breast cancer risk through a tumor promoter effect rather than an initiator effect on preexisting cancer cells.91,92 In addition, any increased risk of breast cancer returns to baseline 10 years after cessation of combined oral contraception.93