For women with BRCA1 or BRCA2 gene mutations, use of hormone replacement therapy after preventive removal of the ovaries and fallopian tubes does not appear to increase the risk of breast cancer. These results were presented at the 2011 annual meeting of the American Society of Clinical Oncology.
Inherited mutations in two genes—BRCA1 and BRCA2—have been found to greatly increase the lifetime risk of developing breast and ovarian cancer. Mutations in these genes can be passed down through either the mother’s or the father’s side of the family.
Options to manage this increased cancer risk include regular cancer screening, chemoprevention (use of medications to reduce risk), or preventive surgery (surgery to remove the breasts and/or ovaries before cancer is diagnosed).
When performed by the time a woman is in her mid-30s or early 40s, preventive removal of the ovaries can substantially reduce the risk of both ovarian cancer and breast cancer. This reduction in cancer risk, however, comes at the cost of an early menopause and symptoms such as hot flashes, sleep disturbances, and vaginal dryness.
Hormone replacement therapy (HRT) can effectively manage these symptoms, but it’s been uncertain whether this is safe for women with BRCA1/BRCA2 mutations. Studies in women without these mutations have indicated the combined (estrogen plus progestin) hormone therapy increases the risk of breast cancer.
To evaluate the risk of breast cancer among BRCA1/BRCA2 carriers who have undergone preventive removal of their ovaries and fallopian tubes, researchers collected information from 795 women with a BRCA1 mutation and 504 women with a BRCA2 mutation.
After ovary removal, breast cancer was diagnosed in 14% of the women who took HRT and 12% of the women who did not take HRT. This difference between groups was not statistically significant, suggesting that it could have occurred by chance alone. By comparison, risk of breast cancer was 22% among women who did not have their ovaries removed and did not take HRT.
These results suggest that short-term use of HRT to manage menopausal symptoms may be an option for BRCA1/BRCA2 carriers who have had their ovaries removed. HRT did not significantly increase the risk of breast cancer in this population.
Reference: Domchek SM, Friebl T, Neuhausen SL et al. Is hormone replacement therapy (HRT) following risk-reducing salpingo-oophorectomy (RRSO) in BRCA1 (B1) and BRCA2 (B2)-mutation carriers associated with an increased risk of breast cancer? Paper presented at: 2011 Annual Meeting of the American Society of Clinical Oncology; June 3-7, 2011; Chicago, IL. Abstract 1501.