WHI Trials Provide New Data on Hormone Therapy for Breast Cancer

After nearly half a century, hormone therapy’s influence on breast cancer incidence and mortality remains controversial, with discordant findings from prospective observational studies and randomized clinical trials. Now, long-term follow-up results from two large Women’s Health Initiative randomized clinical trials in postmenopausal women demonstrate that the use of estrogen alone decreased breast cancer incidence and death while estrogen plus progestin increased breast cancer