Hormones also raise death risk of cancer
Wednesday, October 20, 2010
Women who take a popular hormone replacement drug after menopause not only increase their chances of getting breast cancer but also seem to face an increased risk of dying from the disease, according to new results of a landmark federal study.
The study of more than 12,000 women who were followed for about 11 years produced powerful evidence that deaths from breast cancer were more common among hormone-users, apparently because their cancers had already started to spread.
For years, doctors recommended that women take hormones to alleviate hot flashes and other symptoms of menopause to protect their hearts and generally remain more youthful. But eight years ago, the federally funded Women's Health Initiative revealed that hormones' benefits were outweighed by risks, including heart disease and breast cancer. Hormone use plummeted by more than half, although millions of women still take them.
Since then, women dealing with the life-changing effects of menopause have faced confusing information. Most experts recommend that women who need hormones take the lowest dose for the shortest period of time. Some say that it is safe to use hormones for up to five years; others say that remains unclear. Previous research indicated that the tumors in women who took hormones tended to be small and treatable and did not put them at greater risk of dying from the cancer.
The new analysis by the Women's Health Initiative, published in Wednesday's issue of the Journal of the American Medical Association, found that women who took the combination of estrogen and progestin - sold as Prempro - were more likely to have tumors that appeared to be larger, were often hard to treat and were more likely to have spread to their lymph nodes. But most important, their risk of death appeared elevated.
Coupled with research published last year that found that women who took hormones were about 70 percent more likely to die from lung cancer, the new findings underscore the risks posed by the therapy.
"Women taking estrogen plus progestin are at greater risk from dying from the two leading causes of cancer death in women," said Rowan T. Chlebowski of the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, who led the analysis.
The new breast cancer findings surprised even some experts who have remained more supportive of hormone use.
"This really is a paradigm shift," said Hugh S. Taylor, chief of reproductive endocrinology at Yale University. "There was a whole group of people, including myself, who had been thinking hormone use was associated with an increased detection of breast cancer but not necessarily an increase risk of death from breast cancer. But this really nails it."
Although the study found that hormone use appeared to double the relative risk of dying from breast cancer, several experts stressed that the absolute risk was very low. In the new study, 25 women among those taking the hormones died from breast cancer, compared with 12 among those who took a placebo. The increased risk translates into 2.6 vs. 1.3 deaths from breast cancer each year for every 10,000 women taking hormones, or about 1.3 additional deaths, the study found.
"Let's not throw the baby out with the bath water," Taylor said. "Hormonal symptoms can really be life-changing for many women - changing their ability to concentrate, their mood, their personality. It can be really horrendous. Just because there is a very small risk associated with a therapy doesn't necessarily mean we completely abandon it."
In 2002, more than 110 million prescriptions for hormones were filled; by 2009, the number had dropped to about 40 million, according to IMS Health, which tracks prescription drug sales.