The millions of women who abandoned hormone replacement six years ago when research showed it increased the risk of serious illness are more likely to develop breast cancer than women who didn't take the hormones, research published today suggests.
But the increased risk of heart disease associated with hormone therapy seems to dissipate, according to a long-anticipated follow-up study published in the Journal of the American Medical Association.
Benefits of the pills, including decreased risk of hip fractures and colorectal cancer, also disappeared when women stopped the medications.
Women who took the hormones over the long term should not necessarily be worried today, but they should watch their health carefully, said Dr. Gerardo Heiss, an epidemiologist at the University of North Carolina School of Public Health and one of the study's authors.
"There's a reason to be vigilant," Heiss said. "There's no reason for alarm."
After the original, critical study of the Women's Health Initiative appeared in 2002, prescriptions for hormone replacement therapy drugs dropped sharply.
The Food and Drug Administration and groups such as the American College of Obstetricians and Gynecologists began recommending that hormones be given only to women actively experiencing symptoms of menopause - and then only at the smallest possible dose for the shortest period of time.
Today's report in JAMA reaffirms what researchers learned in 2002, supporting the decision to halt the original trial.
"This is further confirmation about the danger of long-term combination hormone therapy," said Dr. Michael Lauer, prevention chief at the National Heart, Lung and Blood Institute of the National Institutes of Health, which sponsored the study. "Even after stopping therapy, the harms do not just plain disappear."
For a half-century, hormone replacement therapy was pitched to women as a path to staying young, beautiful and healthy. Women took HRT for many years, believing it helped protect against the ills of aging - particularly cardiovascular disease.
They were often given estrogen in combination with a synthetic form of progesterone - two female sex hormones the body no longer produced.
Animal experiments with estrogen backed up the theories; observational studies showed that women who took estrogen and progestin were healthier than those who did not.
