Estrogen-progestin pills do not reduce the risk of ovarian cancer and might even increase it, according to a study that raises more red flags about a once widely accepted treatment for women going through menopause.
“It's more bad news” for hormones, said American Cancer Society epidemiologist Dr. Carmen Rodriguez.
The findings came from the federally funded Women’s Health Initiative study, part of which was abruptly halted in 2002 because of evidence that estrogen-progestin pills raise the risk of breast cancer, heart attacks and strokes.
Previous findings on hormone pills and ovarian cancer have been inconsistent. Some studies, especially those involving estrogen-only pills, showed an increased risk. But some doctors have theorized that combination pills would reduce the risk because they contain hormones similar to those in birth control pills, which have been shown to lower the odds.
The new analysis found that 32 of the 16,608 participants developed ovarian cancer during about 5½ years of follow-up. There were 20 cases in women who took hormones and 12 in those on dummy pills.
A worrisome trend
The difference is not statistically significant because the cancer was so rare, but the trend is worrisome, said lead author Garnet Anderson, of the Fred Hutchinson Cancer Research Center in Seattle. The analysis appears in Wednesday’s Journal of the American Medical Association.
“If women have no menopausal symptoms, they should not be taking” hormone pills, Anderson said.
The analysis is “probably the best we have so far,” said Rodriguez, though questions remain because so few women developed the rare cancer.
Wyeth Pharmaceuticals, which makes the Prempro pills used in the study, downplayed the results. “It does not prove that there’s any kind of causal relationship,” Wyeth’s Dr. Victoria Kusiak said.
Women’s Health Initiative data also have linked hormones with an increased risk of dementia, adding to confounding evidence that the pills might contribute to the very ailments they once were thought to prevent.
Hormone pills are approved for relieving hot flashes, night sweats and other temporary problems of menopause, as well as for preventing bone-thinning osteoporosis.
Wyeth has been saying since the first Women’s Health Initiative results were published in 2002 that hormones remain an effective treatment for menopausal symptoms, and Kusiak reiterated that women seeking relief should take the lowest possible dose for the shortest possible duration.
The company estimates that 1 million women were still taking Prempro pills as of June, down from 3.4 million before the study was halted.
An arm of the government study involving estrogen-only pills is continuing.