New Warnings for Women Taking HRT.
Estrogen-Only Hormone Therapy Linked to Ovarian Cancer
But the health officials did not stop the part of the study evaluating estrogen alone in 11,000 women without uteruses because these women did not appear to have the same increased risks for breast cancer as those on combined therapy. The 11,000 women have been sent letters stating this, but the issue of ovarian cancer has not been addressed.
Marcia Stefanick, MD, who leads the Women's Health Initiative steering committee, says no definitive conclusions on ovarian cancer risk can be made from the NCI study because of its design. Stefanick is an associate professor of medicine at Stanford University.
"Observational studies like this one give us great insight into what hypotheses we should test, but they don't answer the questions," she tells WebMD. "For that you need randomized, clinical trials."
Stefanick says the overall balance of risks vs. benefits is not clear for women taking estrogen alone. She hopes women taking part in the estrogen-only arm of the Women's Health Initiative trial will stay on the study, scheduled to continue until 2005.
"The risks that led us to stop the combined treatment arm of the trial were relatively small, and we have not seen those risks in women taking estrogen alone," she says. "We are committed to the safety of our study participants. We hope that women will continue on the trial so that we can get definitive answers to these questions."
Margery Gass, MD, who is president elect of the National American Menopause Society, says women taking either estrogen alone or combined therapy for relief of menopause symptoms should be reassured that short-term use appears safe.
"Both patients and physicians alike have tried to make decisions regarding hormone therapy with the information they have had at the time," she says. "Now we finally have some definable risks, and women can apply those risks to their lives and their decisions."