By now, women know to be wary, very wary, of taking hormones after menopause. The risks of taking the combination of estrogen and progestin—breast cancer, stroke, serious blood clots, dementia, even, as reported last month, brain shrinkage—have been well established, and women no longer take these hormones for a lifetime to prevent heart disease and bone loss. A new study published today in the New England Journal of Medicine, though, puts an even scarier spin on the breast cancer risks women incur from taking hormone therapy to combat troublesome menopause symptoms like hot flashes and mood swings. Turns out, taking hormones for a full five years doubles your annual risk of getting breast cancer; previous studies by the same researchers found a much smaller 27 percent increased risk for those who took hormones over an average of 5½ years.
"This new finding certainly provides some much-needed guidance for those grappling with whether or how long to take the hormones," study leader and medical oncologist Rowan Chlebowski tells me. He says the motto "smallest dose for the shortest amount of time" should be modified to read: Make it a point not to take hormones for more than two or three years, and take them only if you have severe menopausal symptoms that are interfering with the quality of your life.
Still, there's no reason for women to panic or avoid hormones if they've got superbad symptoms. For one thing, even a doubling in your annual risk doesn't amount to all that much. The typical 50-year-old woman has less than a 1 percent likelihood of getting breast cancer in the next year, so even a doubling in that risk would still leave her with pretty good odds. What's more, when women stop taking hormones, the increased breast cancer risk disappears completely within a year, points out study coauthor Marcia Stefanick, an oncologist at the Stanford Prevention Research Center. Third, the doses used in this study are about twice the low-dose therapy that many doctors are now giving to women.
"We have to assume that lower doses mean lower breast cancer risk, though this hasn't yet been verified in studies," Stefanick says. She recommends low-dose formulations that contain 0.325 milligrams per day of estrogen, instead of a 0.625-mg dose, and 1.5 mg of progestin instead of a 2.5-mg dose. After two or three years, try going off the hormones cold turkey to see if menopausal symptoms recur. If you get hit by hot flashes, night sweats, or moodiness, work with your doctor to taper down your dose.
What about those "natural" bioidentical hormones that celebrities like Suzanne Somers are raving about? I ask her. "We don't have any data on whether they're any safer," she says. "I'd stay away from them."
More on hormone replacement therapy and h ealth from USNews.com: