Study Finds Estrogen Alone Is Risky, Too:
Feds Halt Trial, Citing No Heart Disease Benefit

Saundra Young and Christy Feig

March 2, 2004; Washington, D.C. ( CNN) -- A large government study was stopped after no heart protection was found in women using the hormone estrogen. The federal government is halting a large study looking at the use of estrogen because the hormone replacement appears to have no impact on heart disease and may even cause adverse health effects, the Food and Drug Administration said Tuesday. The FDA said in a statement that the data show that along with no benefit to the heart, the hormone also increases the risk of stroke. However, the study did find that the therapy cut the risk of hip fracture. "The increased risk of stroke with estrogen alone outweighs any benefits found in the study," the FDA said in a statement about the trial, which was carried out by the National Institutes of Health.

In July 2002, the NIH halted prematurely another major clinical trial -- this one of more than 16,000 healthy menopausal women -- that looked at combined estrogen and progestin. NIH scientists said the early data showed the study was too risky to continue. Researchers found an increased risk of invasive breast cancer, heart disease and stroke in study participants compared with women who took placebo. The study had been scheduled to run until 2005. Those results led many women to stop taking combined hormone replacement therapy. And women taking estrogen alone began asking whether they, too, were at increased risk. Early data from the newest NIH study -- which included 11,000 healthy post-menopausal women who had undergone a hysterectomy -- found no increased risk of breast cancer, unlike the previous research. It did discover that women taking estrogen alone had about the same stroke risk as those taking estrogen plus progestin -- eight more strokes per year for every 10,000 women compared to the same number taking dummy pills.

The American Society for Reproductive Medicine, an organization of experts on reproductive hormones, said that treatment choice should be made on a case-by-case basis. "Hormone therapy for short-term treatment of menopausal symptoms remains an appropriate use," the group said in a statement. "However, any use of hormone therapy, including its use for prevention of hip fracture, must be undertaken only after careful evaluation of the risks and benefits for every individual patient." The agency advises women who are using estrogen-containing products for post-menopausal symptoms such as hot flashes to use the medication only when their symptoms are moderate to severe and recommends doctors use the lowest dose possible for the shortest time possible.

Since July 2002, the FDA has been working to update labeling on hormone replacement products. In the past, hormone therapy has been linked in studies with an increased risk for an array of conditions from dementia to asthma.