Estrogen-Only Systemic HT in the Setting of Bilateral Salpingo-Oophorectomy — Safe or Risky?

To clarify the health effects of estrogen-only systemic hormone therapy (HT) in postmenopausal women without a uterus who did or did not undergo bilateral salpingo-oophorectomy (BSO), Women's Health Initiative researchers conducted an 18-year follow-up study involving 9939 women (age range, 50–79) who had been randomized to conjugated equine estrogen (CEE; 0.625 mg daily) or placebo for a median 7.2 years. Endpoints included coronary heart disease, invasive breast cancer, all-cause mortality, and a composite of serious health events (stroke, pulmonary embolism, colorectal cancer, and hip fracture).

Among women aged 50 to 69 without a uterus, systemic estrogen-only HT compared with placebo did not significantly raise risk for serious health e…