NIH halts estrogen trial, citing risk, minor benefit

Hormone therapy relieves menopause symptoms, doesn't stop heart disease

March 03, 2004|By David Kohn | David Kohn,SUN STAFF

The National Institutes of Health ended its major study of hormone replacement therapy yesterday, concluding that while estrogen is a safe short-term treatment for menopause symptoms, it doesn't prevent heart disease and poses a slightly higher risk of stroke.

NIH ended the study a year early, asking nearly 11,000 subjects to stop taking their pills. The agency decided that because estrogen doesn't lower heart disease rates, the women should not be exposed to increased stroke hazards.

At the same time, scientists and doctors said that estrogen by itself is largely safe for treating menopausal discomfort and said women taking the hormone should continue to do so.

"If women are having hot flashes and other symptoms of menopause, they should certainly consider estrogen," said Dr. Barbara Alving, director of NIH's Women's Health Initiative, which oversees the study.

Dr. Nanette Santoro, director of reproductive endocrinology for the Albert Einstein College of Medicine in New York, agreed: "The benefits to be gained from symptom relief outweigh the risk for most women. The risks are small for most women."

But post-menopausal women who have been taking estrogen for longer than five years might want to reconsider their choice, she said: Over that period, the drug's risks might grow.

Yesterday's results come two years after NIH abruptly halted a related study to see whether menopausal women could lower their risk of heart disease by taking estrogen combined with progestin, another female hormone.

The trial found that this widely used combination raised heart attack risk by 29 percent. It also boosted stroke risk by 41 percent, breast cancer risk by 26 percent and cardiovascular disease risk by 22 percent.

Then, last year, NIH stopped a sub-study of the hormones' effect on memory after the estrogen-progestin combination showed an increased risk of dementia in women 65 and older.

The findings seemed to disprove the widely held theory that female hormones could prevent heart disease and other ailments. As a result, millions of American women stopped taking the combination, worried that the drugs might cause more serious problems than they solved.

Doctors emphasized that the estrogen-only data were much less worrisome. Santoro called the news "reassuring" because estrogen does not appear to increase the chances of getting breast cancer or heart disease.

By itself, estrogen increases the risk of uterine cancer, but doctors frequently prescribe it for post-menopausal women who have had hysterectomies and are not at risk for the uterine disease. An estimated 20 million American women have had hysterectomies.

The study found a mix of positive and negative effects: Taking the hormone marginally raises the risk of stroke, but it decreases the chance of hip fractures. Estrogen might also increase the risk of dementia, but it seems to have no effect on breast cancer rates.

Estrogen takers had about eight more strokes per year for every 10,000 women than those taking the placebo, Alva said - comparable to the increased risk of stroke by women who took estrogen and progestin together.

Responding to the NIH news, the Food and Drug Administration said it would review the data and might adjust its recommendations for estrogen.

The FDA has approved estrogen for relief of menopausal symptoms, and for osteoporosis only when other drugs are inappropriate. Experts said the NIH news should not change this.

"Estrogen should not be given to people to prevent disease," said Dr. Robert Rebar, executive director of the American Society for Reproductive Medicine. But he called the risk of stroke "slight" and said that, for some post-menopausal women, taking the drug for more than five years might be worth any increased hazard.

Because estrogen seems to have different effects from the combination of estrogen and progestin, researchers must now account for the disparity.

"What causes the increased risk in the estrogen-plus-progestin group? We have to do more studies," said Dr. Steven Adashek, a professor of obstetrics and gynecology at the University of Maryland Medical School.

Marcia Stefanick, a professor of medicine at Stanford University and a principal investigator in the NIH study, cautioned against assuming that progestin was the culprit for the increased hazard. She noted that the two studies looked at somewhat disparate populations.

Started seven years ago, the latest study examined healthy post-menopausal women ages 50 to 79 who had had a hysterectomy. Half of the subjects were given estrogen, the other half a placebo.

The data released yesterday are preliminary, Alving said, and final results won't be announced until April.

For that reason, Stefanick cautioned that any conclusions must wait until then. "I don't think people should use this information to make decisions about their own hormone use," she said.

Alving and other researchers expressed hope that yesterday's news would not trigger fear over estrogen therapy hazards. The 2002 announcement set off an "overreaction," Alving said: "I would like to have seen a little less emotion and a little more thought."

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