Present and Future

Journal of the American Medical Association Features UTHSC Scientist

Memphis, Tenn. (April 15, 2011) The research of Karen C. Johnson, MD, MPH, professor and interim chair of the University of Tennessee Health Science Center (UTHSC) Department of Preventive Medicine, is featured in the current issue of the Journal of the American Medical Association (JAMA). Dr. Johnson is the local principal investigator of a national study to assess the effects of estrogen therapy alone without progesterone in postmenopausal women with a prior hysterectomy. Dr. Johnson contributed to the JAMA article titled, "Health Outcomes after Stopping Conjugated Equine Estrogens among Postmenopausal Women with Prior Hysterectomy."

In the Women's Health Initiative Estrogen-Alone Trial, nearly 11,000 women aged 50 to 79 enrolled in the large, multicenter study between 1993 and 1998. Approximately 300 women enrolled in Memphis. The trial was conducted since estrogen-alone treatment appeared effective in smaller studies for decreasing the risk of chronic disease in menopausal women and for relieving the "hot flashes" they endure. Of the enrollees, 78 percent agreed to be followed for 10.7 years. In 2004, the National Institutes of Health, the study funder, asked the women to stop taking their study pills as research findings indicated increased risks for strokes, blood clots and other health problems that outweighed any benefits. The women continue to be followed. Current findings reveal that after treatment stops, the risk for strokes and blood clots diminish. However, a slightly decreased risk for breast cancer remains.

"Taking estrogen-alone treatment, even for a short time, is not recommended for postmenopausal women with a prior hysterectomy since it increases their risks for strokes, dementia and other health problems," said Dr. Johnson. She added, "While estrogen-alone therapy results in a decreased risk for hip fracture after initial intake, the reduced risk doesn't last once a woman stops taking the medication. This short-term benefit does not outweigh the danger of strokes, blood clots, dementia and other health issues estrogen alone can cause."

Findings also indicate that taking estrogen alone for preventing chronic disease produces no difference in the rate of heart disease for women taking this medication versus a placebo, or after a woman stops the treatment. In terms of reducing the risk for breast cancer, findings reveal that taking estrogen-alone for up to six years does not increase the risk for breast cancer and appears to decrease it slightly. However, the long-term risks and benefits of taking estrogen alone for six years or less, and then stopping, differ by age group. Younger women in the study appear to have fewer risks for adverse health effects from estrogen-alone therapy than older women in the trial.

Based on findings from the Women's Health Initiative Estrogen-Alone Trial, experts recommend that women who have had a hysterectomy engage in a thorough discussion of the risks and benefits of estrogen-alone with their primary care provider prior to considering the medicine as a treatment for severe postmenopausal symptoms.

The Journal of the American Medical Association, published continuously since 1883, is an international peer-reviewed medical journal published 48 times per year. JAMA is the most widely circulated medical journal in the world. The journal's objective is to promote the science and art of medicine and the betterment of the public health. JAMA publishes original, important, well-documented, peer-reviewed articles on a diverse range of medical topics and enables physicians to remain informed in multiple areas of medicine, including developments in fields other than their own. Further, JAMA fosters responsible debate and research, and informs readers about nonclinical aspects of medicine and public health, including political, philosophic, ethical, legal, environmental, economic, historical, and cultural factors. For more information about JAMA, visit