HRT Increases Risk of Breast Cancer, Large British Study Finds
Women who take hormone replacement therapy are more at risk of developing breast cancer than women who do not, according to a study of more than one million British women to be published in the Lancet, the Washington Post reports (Stein, Washington Post, 8/8). The Million Women Study, "by far the largest" to assess the effects of hormones on breast cancer, was funded by the British government and the not-for-profit Cancer Research UK, the New York Times reports. About half of the women were taking HRT, and the other half were not. Women who took hormones from the beginning of the study showed a 66% increased risk of getting breast cancer and a 22% greater chance of dying from the disease by 2002 compared with those not taking hormones (Altman, New York Times, 8/8). The researchers found that women who took any combination of hormones -- either estrogen alone or combined with progestin -- and in any form, including pills, patches or gels, were "significantly more likely" to develop breast cancer and that the risk increased the longer women continued the treatment, the Post reports. Women who took estrogen alone were 30% more likely to get breast cancer than non-users, and the risk was nearly double for women taking combination estrogen-progestin therapy compared with non-users (Washington Post, 8/8). Five years after they stopped taking HRT, women were no more at risk for developing the disease than those who had never taken hormones, the Times reports. The researchers estimated that 20,000 of the women in the study developed HRT-related breast cancer; 15,000 cases were linked to combination therapy (New York Times, 8/8). The researchers also calculated that over a decade, HRT would result in an extra 10,000 cases of breast cancer among women 50 to 64 in Britain and an extra 100,000 in the United States (Washington Post, 8/8).
Dr. Marcia Stefanick, an associate professor of medicine at Stanford University, said the results showed that the longer a woman continues HRT, the "worse off" she is. However, Dr. Leslie Ford, associate director for clinical research in the National Cancer Institute's Division of Cancer Prevention, said it is "comforting" that the risk for breast cancer decreased gradually for those who stopped the therapy. An accompanying editorial in the Lancet said long-term users of combination hormone therapy should stop the treatments as soon as possible but advised physicians to "convey that message in a supportive way" to avoid panic among patients (New York Times, 8/8).This is part of the California Healthline Daily Edition, a summary of health policy coverage from major news organizations. Sign up for an email subscription.