Study finds hormone treatments in some do more harm than good

Keith Kinkade provided a cool shower for Tiger Jack at a temporary pen near Perryville, Mo., Tuesday afternoon. By Susan Okie ~ The Washington Post

WASHINGTON -- A landmark scientific study has found that giving hormones to healthy menopausal women does more harm than good, a finding that overturns doctors' long-held beliefs about the treatment's benefits and creates new uncertainty for millions of women.

The stunning findings from the federally funded Women's Health Initiative (WHI), released Tuesday, appear to dash the longstanding hope that taking the hormones estrogen and progestin after menopause would help women live healthier lives. A study of the two-hormone combination was stopped three years early when it was found to increase the risk for breast cancer. In addition, women on the treatment suffered more heart attacks, more strokes and more life-threatening blood clots than those given a placebo.

Although the hormones did have some benefits -- reducing the frequency of hip fractures and of colon cancer -- the WHI's study of more than 16,000 women found that those pluses were outweighed by the treatment's negative effects on breast cancer, heart disease and circulatory disorders.

"Considering that millions of American women might consider taking estrogen plus progestin ... that could translate into tens of thousands of cases of breast cancer or cardiovascular disease over several years," said Jacques Rossouw, acting director of the WHI.

Of approximately 50 million postmenopausal women in the United States, about 14 million are taking some form of hormone treatment, either to relieve common menopausal symptoms or in the hope of preventing osteoporosis or other chronic diseases. A number of recent studies have cast doubt on the value of long-term hormone therapy, but the long-awaited WHI study is the first large clinical trial to measure the treatment's impact on healthy women.

Experts said women who are taking the hormones should not panic, but should consult with their doctors about whether to continue. Several said women who take the two hormones to relieve hot flashes and other symptoms of menopause should use the treatment for as brief a period as possible, and those wishing to prevent osteoporosis should probably choose alternatives to hormones.

The study found that breast cancer risk did not rise significantly until the fourth year of treatment, but that women's risk of heart attacks and blood clots increased as soon as they began taking hormones.

"There's really no safe period," Rossouw said.

The WHI study that was stopped had been testing a combination of estrogen and progestin. About 6 million U.S. women currently take the two hormones, according to WHI researchers. Another 8 million U.S. women who have had hysterectomies take estrogen alone.

For women taking estrogen alone, the balance of risks and benefits remains uncertain. Researchers said that so far, no increase in breast cancer risk has been seen in a WHI study evaluating the use of estrogen alone, and they currently plan to continue that study until 2005.

Women in the study, who were between 50 and 79 years old, were randomly prescribed the hormone combination or a placebo and their health was monitored for an average of 5.2 years. Neither they nor their doctors were told which treatment they were taking.

There was no difference in death rates between the two groups. However, women on the hormone treatment had a 26 percent higher incidence of breast cancer, a 29 percent higher incidence of heart attacks, a 41 percent higher incidence of strokes and twice as many blood clots in the lungs and leg veins as those taking the placebo. In contrast, the hormone-treated women had 37 percent fewer hip fractures and a 34 percent lower rate of colon cancer.

The study found that the frequency of these effects in hormone users did not differ by age, ethnic group or prior health status.

For an individual woman, the risk of suffering a serious adverse effect of hormone treatment is low, researchers said. For instance, among 10,000 women taking the two hormones for one year, there would be seven more heart attacks, eight more strokes, eight more lung blood clots, eight more breast cancers, six fewer colon cancers and five fewer hip fractures than among a comparable group not on the treatment.