New study sounds warning on hormone replacement therapy
An analysis by a federal task force finds that hormone replacement therapy’s risks may outweigh the benefits for women who are past menopause and healthy but hoping to ward off dementia, bone fractures or heart disease.
The latest recommendation, published Monday in the Annals of Internal Medicine, comes from an organization accustomed to controversy. In recent months, the task force has recommended against routine breast cancer screenings for most women younger than 50. It has also urged abandonment of the prostate-specific antigen, or PSA, test that has become a standard part of older men’s yearly physicals.
Its latest recommendation could be a bit less controversial but is likely to have detractors among physicians who believe that the dangers of hormone replacement therapy for menopausal women have been overblown.
The recommendation is largely based on revised analyses of the landmark Women’s Health Initiative, a 15-year study involving more than 160,000 women. It comes a decade after the study first linked hormone replacement therapy with higher rates of invasive breast cancer. Those initial findings prompted droves of women to abandon or avoid hormone therapy.
But a decade of subsequent research tempered much of the fear, and preliminary but conflicting studies had suggested that some postmenopausal women taking hormones might benefit from lower rates of bone fractures, dementia and heart disease.
The task force found limited evidence that hormones protect against bone fractures, and no evidence that they reduce the most probable threat — heart disease. It also found that for most menopausal women using hormone therapy, the risk of developing dementia later in life actually rose a bit.
Against such sparse benefits, the panel weighed relatively new evidence of the risks, including a significantly higher rate of life-threatening blood clots in the legs and lungs, a greater probability of gallbladder disease and increased risk of urinary incontinence that persisted in studies for at least three years.
Dr. Kirsten Bibbins-Domingo, chairwoman of the panel, said members took pains to put the possible benefits of hormone replacement therapy in context. One form of the therapy — estrogen alone — did appear to slightly reduce the incidence of breast cancer. Invasive breast cancer looms large as a concern to many women but affects just 11% of them after menopause.
That possible protective effect became less consequential when weighed against hormone therapy’s effects on far more likely risks to women’s health, said Bibbins-Domingo, professor of medicine and of epidemiology and biostatistics at UC San Francisco: It fails to reduce the risk of heart disease, which will affect 30% of women who live past menopause.
It slightly increased the likelihood of dementia, which will affect 22% of all postmenopausal women. It was linked to a higher likelihood of stroke, affecting 21% of these women. And although it slightly reduced the rate of hip fractures, which affect 15% of women past menopause, other medications can do that more effectively.
Today, 1 in 5 postmenopausal American women uses hormone replacement therapy, mostly to treat symptoms such as hot flashes, night sweats and vaginal dryness. That is about half the rate in 2002, when 40% took hormones. But as revisions to the Women’s Health Initiative have relaxed widespread reticence about the medications among women and their physicians, hormone use appears to be creeping back up.
“You would think there wasn’t much room for concern,” said Dr. Rowan Chlebowski, the principal investigator for the Women’s Health Initiative and a professor of medicine at UCLA‘s Harbor campus. “That’s not exactly correct.”
In the last year, the North American Menopause Society, healthcare professionals active in promoting the health of women as they make the transition out of childbearing years, has issued guidance on hormone therapy that has reopened the door to its widespread use, Chlebowski said.
“This [Preventive Services Task Force] recommendation kind of says, ‘Not so fast.’ … It’s a pretty sophisticated argument to make,” Chlebowski said.
The task force said its decision to recommend against hormone therapy for prevention of chronic diseases was based on “at least fair” evidence that the harm outweighed the benefits, or that its use was ineffective. But Bibbins-Domingo, lead author of the report, said the panel struggled with two slightly different mixes of potential harm and benefits: those linked to standard hormone therapy, which includes estrogen and progestin and is used by most women; and those linked to estrogen alone, which is prescribed for women who have undergone uterus removal.
Estrogen alone appears to offer some benefits that estrogen-progestin does not. The task force found that for women past menopause, estrogen offers a small measure of protection against breast cancer, for reasons that are not yet well understood. Only women who have had hysterectomies can take estrogen alone because it has been linked to uterine cancer.