"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 5 1/2 years of follow-up. There were 20 cases in women who
took hormones and 12 in those on dummy pills.
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.
