Hormone Therapy May Increase Cancer Risk
Published April 2008
Hot flashes, mood swings and fatigue are some menopause symptoms that may be alleviated by hormone therapy.
But a study from the Women’s Health Initiative (WHI) reveals estrogen plus progestin therapy may also increase a women’s chances of something she doesn’t want—cancer.
Researchers across the country, including Margery Gass, MD, professor of obstetrics and gynecology at UC, followed up on the risks and benefits of hormone replacement therapy experienced by 15,730 of the 16,608 women who participated in the WHI.
The follow-up study found that while risks linked with estrogen-progestin pills, such as heart disease and blood clots, seem to diminish after women stopped taking them, the overall risk of cancer actually increases.
The rate of cancer for the hormone user group was 1.56 percent per year (281 women) versus 1.26 percent per year (218 women) for the non-users.
The findings are detailed in the March 5, 2008, issue of the Journal of the American Medical Association.
“The increased risk is small but when you multiple that by the millions of women who use estrogen plus progestin pills, it needs to be considered,” says Gass.
“There was a time when doctors thought that having postmenopausal women take hormone therapy long-term actually helped keep them healthy,” says Gass. “That’s why the WHI study was developed—to see if this concept was grounded in science.”
The largest study of its kind, the WHI began in 1991 and was designed to study the effects of hormone therapy on postmenopausal women’s health.
Researchers halted the study in 2002 after finding an increased risk of breast cancer and no benefit for heart disease among women taking estrogen plus progestin therapy.
Gass says most women should feel comfortable using hormone therapy but that they should consider using it short-term.
“Women who use hormones need to do routine cancer screenings including mammograms,” says Gass. “There are risks associated with many medications—but we want the benefits to outweigh the risks.”