By LAURAN NEERGAARD, AP Medical Writer
WASHINGTON (AP) - Government scientists abruptly ended the nation's biggest study of a type of hormone replacement therapy, saying long-term use of estrogen and progestin significantly increase women's risk of breast cancer, strokes and heart attacks.
Six million American women use this hormone combination, either for short-term relief of hot flashes and other menopausal symptoms or because of doctors' long-standing assumptions that long-term use would prevent heart disease and brittle bones and generally keep women healthier longer.
In fact, there are serious risks to using the hormones for years, risks that far outweigh the few benefits, the National Institutes of Health announced Tuesday.
The hormones harm, not protect, the heart -- they actually increase previously healthy women's risk of a heart attack by 29 percent and a stroke by a stunning 41 percent. They also increase women's chances of breast cancer by 26 percent.
On the good side, the hormones cut by a third the risk of colon cancer and hip fractures -- but there are other, safer ways to fend off those illnesses, doctors noted.
So the NIH stopped the 16,600-woman study three years early, and is advising other women who use the estrogen-progestin combination to ask their doctors if they, too, should quit.
"We want to get the word out to women and their doctors that long-term use of this therapy could be harmful," said Dr. Jacques Rossouw, acting director of the NIH's Women's Health Initiative, which sponsored the study.
Women may still want to use the hormones for a short period to treat menopause symptoms such as hot flashes, he said. But for how long?
"There is no really safe period," he acknowledged, noting that the heart attack risk hit during women's first year taking the hormones. "As short a period as you can get away with in order to manage the menopausal transition."
Other researchers were even more negative.
"We recommend that clinicians stop prescribing this combination for long-term use," wrote Dr. Suzanne Fletcher of Harvard Medical School in an editorial accompanying the study results posted on the Web site of the Journal of the American Medical Association. "Risks from the drug add up over time."
The study's leaders stressed that women shouldn't panic because personal risk is pretty small.
In one year, for every 10,000 women who take the estrogen-progestin combination there will be eight more breast cancers, eight more strokes and seven more heart attacks -- and six fewer colon cancers and five fewer hip fractures -- compared with 10,000 women who didn't take the pills.
However, because millions take the hormones, those numbers can add up to thousands of illnesses, Rossouw noted.
To use estrogen or not has long been a vexing question for women entering menopause. While the study seems definitive, it doesn't settle all the questions:
Wyeth Pharmaceuticals, which makes Prempro and other estrogen supplements, said the main reason women start hormone therapy is to relieve hot flashes, night sweats or vaginal problems.
"It is important to recognize the critical role" the hormones play for those women, said Wyeth vice president Dr. Victoria Kusiak.
(Copyright 2002 by The Associated Press. All Rights Reserved.)