Author: Amy Orciari Herman
Edited by William E. Chavey, MD, MS
All types of menopausal hormone therapy (HT), except vaginal estrogen, are associated with increased breast cancer risk, according to a large meta-analysis in the Lancet.
Researchers examined prospective data on over 100,000 postmenopausal women who developed breast cancer. Among the other findings:
- Excess risk for breast cancer was greater for estrogen-progestogen combinations than for estrogen-only formulations.
- Breast cancer risk increased with duration of HT use, but among current users, risk was elevated even during the first 4 years of use (for example, 1–4 years of estrogen-progestogen was associated with a 60% increased risk relative to nonuse).
- Increased breast cancer risk persisted more than 10 years after stopping HT.