Reassessing Benefits and Risks of Hormone Therapy

Recent randomized clinical trials of postmenopausal hormone therapy have informed clinical decision making and provided insights that help identify appropriate candidates for treatment. A decline in the use of hormone therapy began precipitously in 2002 with publication of data from the Women's Health Initiative. This review examines the scientific literature surrounding this major change in practice and comments on the equilibrating process now taking place. Notably, the incidence of most of the medical conditions adversely affected by hormone therapy increases with age. As a result, recently menopausal women—those most interested in using hormone therapy—are at lower absolute risk of adverse events than older women. A critical mass of data now suggests that age and time since menopause may also modify relative risks of selected outcomes with use of hormone therapy, but this warrants further study. Duration of hormone therapy use also appears to influence risk, with the occurrence of certain outcomes (such as venous thrombosis) being highest in the first 1 or 2 years of hormone therapy use and others (such as breast cancer) increasing with longer duration of hormone therapy use. The conflicting results for some outcomes from the estrogen arm and the estrogen-progestin arm of the Women's Health Initiative suggest that progestins influence risk of several diseases, particularly breast cancer. Quantifying the benefits and risks of estrogen and estrogen-progestin by age group makes it possible to discuss pros and cons of hormone therapy in a more clinically relevant manner with patients. Hormone therapy remains a viable short-term option for the management of moderate to severe vasomotor symptoms in recently menopausal women who are in generally good health. However, due to known risks, it should not be initiated or continued for the express purpose of preventing cardiovascular disease or other chronic diseases.