Estrogen Causes Breast Cancer
METHODS. To quantify the relation between the use of hormones and the risk of breast cancer in postmenopausal women, we extended our follow-up of the participants in the Nurses Health Study to 1992. The women were asked to complete questionnaires every two years to update information on their menopausal status, use of estrogen and progestin preparations, and any diagnosis of breast cancer. During 725,550 person-years of follow-up, we documented 1935 cases of newly diagnosed invasive breast cancer. RESULTS. The risk of breast cancer was significantly increased among women who were currently using estrogen alone (relative risk, 1.32; 95 percent confidence interval, 1.14 to 1.54) or estrogen plus progestin (relative risk, 1.41; 95 percent confidence interval, 1.15 to 1.74), as compared with postmenopausal women who had never used hormones. Women currently taking hormones who had used such therapy for 5 to 9 years had an adjusted relative risk of breast cancer of 1.46 (95 percent confidence interval, 1.22 to 1.74), as did those currently using hormones who had done so for a total of 10 or more years (relative risk, 1.46; 95 percent confidence interval, 1.20 to 1.76). The increased risk of breast cancer associated with five or more years of postmenopausal hormone therapy was greater among older women (relative risk for women 60 to 64 years old, 1.71; 95 percent confidence interval, 1.34 to 2.18). The relative risk of death due to breast cancer was 1.45 (95 percent confidence interval, 1.01 to 2.09) among women who had taken estrogen for five or more years.
CONCLUSIONS. The addition of progestins to estrogen therapy does not reduce the risk of breast cancer among postmenopausal women. The substantial increase in the risk of breast cancer among older women who take hormones suggests that the trade-offs between risks and benefits should be carefully assessed.
N Engl J Med 1995 Jun 15;332(24):1589-93.
Government Warns Against Hormone Therapy
Oct. 15, 2002(AP) Women should not use estrogen and progestin supplements in hopes of preventing bone loss or other chronic ailments, the government said Tuesday.
Federal scientists broke the news in July that long-term use of the combination hormone therapy significantly increased women's risk of breast cancer, heart attacks and strokes.
The news caused dismay and confusion for millions of American women. Many used the combination not just in hopes of long-term health but to relieve short-term menopausal symptoms such as hot flashes and night sweats, and wondered how long they could safely use hormones for that purpose.
Now the independent panel charged by the U.S. government to set the nation's disease-prevention guidelines has weighed in, with recommendations not likely to settle the confusion.
The clear risks of routine estrogen-and-progestin use outweigh the few long-term benefits, such as bone strength, the U.S. Preventive Services Task Force said Tuesday. But when it comes to menopause symptom relief, the panel urged women to discuss their personal disease risks with their health provider in choosing whether to try hormones.
For example, most discussion of hormone therapy's risks has centered on long-term use, yet the risk of heart attack actually rises in the first year women swallow the pills, said task force co-chairwoman Dr. Janet Allan. A woman with high cholesterol or high blood pressure might make a different decision on using hormones for hot flashes than a healthier woman would.
"This is tough for women," Allan acknowledged.
The task force last examined hormone therapy in 1996, calling the evidence too paltry to decide if women should use it. But doctors' and patients' enthusiasm for hormones overrode that cautionary note, and an estimated 6 million women were taking the estrogen-progestin combination when the National Institutes of Health announced the bad news in July.
Millions more are thought to be taking estrogen alone, something reserved for women who have had their uterus removed. The task force said there's not enough evidence to know yet if estrogen-only therapy is any safer than combination therapy; a study of that question is continuing.
Hormone therapy, breast cancer risk confirmed -NIH (National Institute of Health)
CHICAGO, Nov 29 (Reuters) - A federal study confirmed that women taking hormone replacement therapy are more likely to get breast cancer, though the risk plummets after halting treatment, the National Institutes of Health said on Friday.
"It's not a lifetime of risk they are getting" with this treatment, said Robert Spirtas, a contraception and reproductive health specialist at the NIH and senior author of the study.
Thousands of women taking so-called HRT treatment were advised to stop in July after a separate federal human trial found the most popular form of HRT -- Wyeth's (NYSE:WYE - News) PremPro -- raises the risk of cancer.
Spirtas' NIH study of about 3800 post-menopausal women reported Friday found that women taking PremPro or equivalent drugs -- a mix of the hormones estrogen and progestin -- were 1.54 times more likely to get breast cancer than their counterparts not on the treatment.
Yet the risk begins to drop to normal just six months after stopping combined hormone treatment, according to study results published in the December 2002 issue of the journal Obstetrics & Gynecology.
The NIH studied post-menopausal women on hormone replacement therapy for five years or more.
Some women only take the therapy for several months when they have severe symptoms like hot flashes and vaginal dryness, while others have been on it for 15 to 20 years, Spirtas said.
The U.S. Food and Drug Administration has strengthened warnings on Wyeth's PremPro and Premarin, which uses only estrogen.
Wyeth has said prescriptions for PremPro have fallen 40 percent, and those for Premarin have slumped 15 percent since news of those studies emerged.
Doctors still disagree on whether combined HRT, taken by an estimate 6 million U.S. women, is too risky to be widely prescribed.
(--with reporting by Maggie Fox)