Abstract
Purpose of Review
The present review critically assesses contemporary evidence characterizing the association between hormonal contraception (HC) and/or menopausal hormone replacement therapy (MHT) and breast cancer risk in patients considered “high risk.”
Recent Findings
Prospective studies of hormonal contraception methods for BRCA 1 mutation carriers do not demonstrate an association between combined oral contraceptives (COC) and hormone receptor-positive breast cancer, findings consistent with those seen from systematic reviews evaluating this risk in patients with a family history of breast cancer. The Centers for Disease Control and Prevention (CDC) assigns progesterone-only and combined contraception a medical eligibility criteria (MEC) rating of 1, denoting no restrictions on use for those with benign breast disease and a family history of breast cancer. These guidelines include the etonogestrel implant, injected medroxyprogesterone acetate, levonorgestrel intrauterine device, combined oral contraceptive pill, patch, and intravaginal ring, and the recommendation highlights their overall safety in this population. However, the intravaginal ring, which contains the lowest systemic dose of ethinyl estradiol, as well as the locally-acting progestin intrauterine device systems can be considered for those concerned about hormonal exposure. The small potential breast cancer risk increase observed with progesterone-based birth control methods in few studies should be evaluated in the context of other risk factors such as lower parity in those using long-acting reversible contraception (LARC) methods. A large meta-analysis did not find an increased risk of breast cancer in BRCA ½ mutation carriers receiving estrogen-alone menopausal hormone replacement therapy, although progestin-containing regimens may warrant further study in high-risk populations.
Summary
Most of the existing literature analyzing the risk of breast cancer associated with the use of HC and MHT is comprised of observational data and, therefore, vulnerable to selection and information bias.