Press Releases: Northwest
April 14, 2004
National study shows estrogen-alone has both risks and benefits
276 local women involved in study at Kaiser Permanente Center for Health Research
PORTLAND, Ore. – The latest findings from the Women's Health Initiative (WHI) show that estrogen-alone hormone therapy increased postmenopausal women's risk of stroke and blood clots, decreased their risk of hip and other fractures, and had no effect on their risk of heart disease, breast cancer, and colon cancer. These findings appear in the April 14 issue of The Journal of the American Medicine Association.
The WHI estrogen-alone study, conducted at 40 clinical centers across the U.S., involved 10,739 generally healthy postmenopausal women ages 50-79 who did not have a uterus. Half of the women received 0.625 mg/day of conjugated equine estrogens (Premarin™), and half received a placebo. This study was stopped early in February 2004, because early findings showed the hormone increased the risk of stroke and did not reduce the risk of heart disease, a key question of the study. In July 2002, a separate WHI study of estrogen plus progestin among postmenopausal women with a uterus was also stopped early because of increased risks of breast cancer, heart disease, stroke and blood clots, which outweighed the benefits of a reduced risk of hip fracture and colon cancer.
"These new findings are not great news for women," says Cheryl Ritenbaugh, PhD, principal investigator for WHI at Kaiser Permanente's Center for Health Research, "but they are certainly better for some women than the estrogen plus progestin findings two years ago. Women in their 50's with hysterectomies who are taking estrogen-alone for relief of menopausal symptoms may feel heartened to hear that there is no increased risk of breast cancer from estrogen-alone. Certainly estrogen does not prevent most chronic diseases, but the safety concerns raised by the estrogen alone are much smaller than those raised by the estrogen plus progestin results."
National guidelines for estrogen plus progestin and estrogen-alone are that women should not take these hormones for preventing diseases, especially heart disease. The recommendation is that hormone therapy should only be used to treat menopausal symptoms and used at the smallest effective dose for the shortest possible time.
Kaiser Permanente's Center for Health Research, founded in 1964, is a not-for-profit research institute whose mission is advancing knowledge to improve health.
Kaiser Permanente is a group practice health care organization serving the health needs of 8.2 million people in nine states and the District of Columbia, including 440,000 people in Oregon and Southwest Washington.
