1996.02.06 : Pepi Study Findings Lead to Changes in Women's Health Initiative

The Women's Health Initiative (WHI), the largest prevention study ever funded by the National Institutes of Health, responded promptly to the findings from the Postmenopausal Estrogen/Progestin Interventions (PEPI) study. In this week's Journal of the American Medical Association, PEPI investigators report that a large proportion of women with a uterus who received estrogen developed adenomatous endometrial hyperplasia. If not treated, a small percentage of adenomatous hyperplasias may progress to cancer. Acting on preliminary data from PEPI, since December 16, 1994, the WHI investigators have not enrolled any WHI participant with a uterus to the estrogen arm of the study. Instead, women with a uterus could enroll in the arm receiving estrogen in combination with progestin or the arm receiving an inactive pill. As confirmed by the PEPI results, the progestin will prevent the development of endometrial hyperplasia. Women with a uterus who had previously been assigned to estrogen alone were switched to the combination therapy in the spring of 1995.