Another study links hormones with breast cancer
CHICAGO (AP) — A new study adds to the growing body of evidence that recent, long-term use of hormone supplements after menopause may increase the risk of breast cancer.
Women who had taken estrogen alone or estrogen plus progestin for at least five of the preceding six years were about 70 percent more likely than nonusers to develop breast cancer, the study found.
The increased risk was about 50 percent for developing ductal cancer — which occurs in the milk ducts — and about threefold for developing lobular tumors, which form in the milk-producing glands and account for about 10 percent of all breast cancer cases.
The study further complicates the complex question of whether to take hormones after menopause.
Estrogen supplements are taken by millions of women to ease hot flashes, brittle bones and other symptoms of menopause.
For years, doctors also thought the hormones ward off heart attacks, but more recent studies have challenged that belief. Another recent study questioned whether they are effective in improving a woman’s mood and energy level.
The latest study is in line with recent research linking long-term hormone use with breast cancer. However, it lacked information on participants’ habits that could influence breast cancer risk — including alcohol use, physical activity and breast-feeding.
The study was published in Wednesday’s Journal of the American Medical Association and was led by researchers from the Fred Hutchinson Cancer Research Center in Seattle.
It included 705 women ages 50 to 74 who were diagnosed with breast cancer between 1990 and 1995. They were compared with a control group of 692 women.
The findings suggest that nonusers of hormones have an annual incidence of ductal cancer of about 230 per 100,000 women, compared with 349 ductal cases per 100,000 women with recent hormone use of five years or more.
Lobular cancer would develop among nonusers in 23 per 100,000 women a year and in 70 per 100,000 women who have had five or more years of recent hormone use.
Only 91 of the 705 study participants with breast cancer developed the lobular kind, and just 17 of the lobular group were long-term recent users of hormone supplements.
Eugenia Calle, the American Cancer Society’s director of analytic epidemiology, said the latest findings are consistent with other research suggesting little increased risk of breast cancer for hormone use of under five years or long-term use in the distant past.
Most women who take hormones do so for less than five years, said Dr. Eric Bieber, chairman of obstetrics and gynecology at Geisinger Health Systems in Danville, Pa.
Bieber questioned the study results based on the scant data.
“I don’t think it’s a settled issue,” he said.