Menopausal Hormone Therapy and the Breast: A Review of Clinical Studies

Background: Women in the peri- or postmenopause can experience symptoms related to the gradual degradation of ovarian function. Hormone replacement therapy (HRT) is the most effective therapy to treat common menopausal symptoms such as hot flashes and vaginal discomfort. However, safety concerns have been raised revolving, among others also, around the risk of breast cancer. Methods: This article is based on a selective literature search for relevant studies regarding HRT use and the risk of breast cancer in the general population or BRCA carriers, the risk of breast cancer recurrence, or the risk of breast cancer in situ. Summary: HRT can lead to little or no increase in breast cancer risk. The risk depends on the duration and composition of the HRT and decreases after stopping the treatment. Data assessing the oncological safety of HRT after breast cancer are inconsistent. According to current knowledge, HRT is fundamentally contraindicated after breast cancer but can be individually considered after a risk-benefit assessment and when nonhormonal therapies have failed. The same applies to HRT after DCIS, which should not be routinely offered but nonetheless can be considered in individual cases. HRT can be offered up to the age of natural menopause for BRCA mutation carriers who are undergoing risk-reducing bilateral salpingo-oophorectomy and do not have a personal history of breast cancer, but is contraindicated in BRCA mutation carriers who have already had breast cancer. (c) 2023 S. Karger AG, Basel