Still, the findings are likely to revive questions about just how to balance the risks and benefits of estrogen-progestin therapy in early menopause. Partly because cardiovascular risks seem to accrue only in older women on HRT, some experts have suggested that women seeking relief from symptoms in their 50s can take the drugs for up to five years without concern. But often the general advice to limit time on medications hasn't been translated into any specific guidance on when to consider going off HRT, says Rowan T. Chlebowski, M.D., a cancer specialist at Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center and lead investigator of the Women's Health Initiative, who coauthored an editorial accompanying the British study. "Few doctors are saying, 'After a year or two years, let's stop and see if the symptoms return and you still need the treatment.' I think people will just tend to stay on it," he says.
Increased risk of death from breast cancer
Chlebowski and his coauthors published an analysis of Women's Health Initiative data in the Oct. 20 Journal of the American Medical Association addressing another long-standing question about HRT: whether breast cancers associated with the therapy tend to be relatively nonaggressive and treatable.
In fact, the study found, the therapy seemed to raise a woman's likelihood of dying from breast cancer, an outcome also observed among women in the Million Women Study.
"Estrogen plus progesterone increases the frequency of death from lung cancer [a finding published in 2009] and breast cancer, the two most common causes of cancer death in women," says Chlebowski. "That really sounds like something you want to be hesitant about taking."
Katharine Greider lives in New York and writes about health issues.