Menopausal women taking hormone replacement therapy faced a small increased risk for cancer for more than two years after they stopped, but heart problems linked with the pills seemed to disappear after they stopped taking them, researchers said on Tuesday.
The study of more than 15,000 women who took the hormones for more than five years found that the chance of developing cancer remained elevated well after they quit, which many did after an earlier stage of the study showed that the risks outweighed the benefits.
A previous study by the Women's Health Initiative of U.S. found women taking ombination therapy of estrogen and progestin doubled their risk of blood clots, and raised their risks of stroke and heart attack. Progestin is used to offset the heightened risk of uterine cancer from taking estrogen.
After the women stopped therapy, their heightened risk of breast cancer remained roughly the same. But their risks of heart attack, blood clots and stroke receded quickly back to levels among women who had not taken hormone therapy.
The ancillary benefits of combination hormone therapy -- lower risks of colon cancer and bone fractures -- also disappeared after therapy was stopped.
"The hormones' effects on breast cancer appear to linger," said Dr. Leslie Ford of the Division of Cancer Prevention at the NIH's National Cancer Institute. "These findings reinforce the importance of women getting regular breast exams and mammograms, even after they stop hormone therapy."
The findings underscore the now-standard recommendation that women who take hormones to relieve hot flashes and other effects of menopause should use the lowest possible dose for the shortest time, said Marcia Stefanick of Stanford University, who chairs the steering committee for the federally funded Women's Health Initiative.
And the millions of women who have taken the hormones should be monitored closely for cancer, especially breast cancer, she said.
(Xinhua/Agencies March 5, 2008)