Study of hormone therapy shows some risks persist

By Andrew Stern

CHICAGO (Reuters) - A follow-up analysis of women taking hormone replacement therapy found that their heightened risk of breast cancer persisted even after they stopped taking the drug combination, researchers said on Tuesday.

The Women's Health Initiative study was halted prematurely in 2002 because of a 24 percent higher risk of breast cancer associated with the combination therapy of estrogen and progestin. Progestin is used to offset the heightened risk of uterine cancer from taking estrogen.

The original study found women taking the combination of hormones also doubled their risk of blood clots, and raised their risks of stroke and heart attack.

The overriding conclusion from the two Women's Health Initiative trials involving 27,347 post-menopausal women, aged 50 to 79, was that the overall risks of long-term use of hormone therapy outweighed the benefits.

The 2-1/2-year follow-up analysis, led by Gerardo Heiss of the University of North Carolina and published in the Journal of the American Medical Association, assessed through 2005 the health of 15,730 women who took the combination of hormones.

After the women stopped therapy, their heightened risk of breast cancer remained roughly the same. But their risks of heart attack, blood clots and stroke receded quickly back to levels among women who had not taken hormone therapy.

The ancillary benefits of combination hormone therapy -- lower risks of colon cancer and bone fractures -- also disappeared after therapy was stopped.

"The good news is that after women stop taking combination hormone therapy, their risk of heart disease appears to decrease," said Dr. Elizabeth Nabel, director of the National Heart, Lung, and Blood Institute, part of the U.S. National Institutes of Health that sponsored the original WHI study.