Torrance, Calif. (April 11, 2002) – Surprising results from a new study may quell concerns about the safety of using tamoxifen to reduce breast cancer risk in elderly women, suggesting that both tamoxifen and estrogen have similar effects on the brain. The study was conducted at Harbor-UCLA Research & Education Institute (REI) in Torrance, California by research collaborators Rowan Chlebowski, M.D., Ph.D. and Thomas Ernst, Ph.D. and Linda Chang, M.D., of Brookhaven National Laboratory in New York. The findings will be published in the April 17 issue of the Journal of the National Cancer Institute and promise to advance breast cancer risk reduction as an achievable medical objective in the near future.
“Based on the increase in hot flashes that are associated with tamoxifen, it has been suggested that the drug blocks the potentially favorable effects of estrogen on the brain. We’ve found just the opposite,” said Dr. Chlebowski. “ We were surprised to find similarities between the two groups in that women who have been treated with tamoxifen had lower levels of myo-inositol, a chemical that increases in response to brain injury. Women who took estrogen also had lower levels of the chemical,” he added.
This study is unique in that it uses Proton Magnetic Resonance Spectroscopy (MRS), a non-radioactive brain imaging technique to measure levels of cerebral metabolites – in this case myo-inositol – to predict the effects of tamoxifen. The study compared levels of myo-inositol in 16 breast cancer survivors who had been treated with tamoxifen for at least two years, 27 healthy women who had been treated with preventive estrogen replacement therapy for at least two years, and 33 healthy women who had not received any treatment.
Study participants were between the ages of 65 and 80 who did not have any neurologic diseases. Dr. Chlebowski and his collaborators concluded that both tamoxifen and estrogen may be neuroprotective and may have favorable modulatory effects on aging. Dr. Chlebowski noted, however, that future studies would be necessary to observe the long-term effects of such therapies on cognitive function.
Dr. Chlebowski is board certified in internal medicine and medical oncology. He is Chief, Division of Medical Oncology and Hematology at Harbor-UCLA Medical Center and a recognized authority on breast cancer. He has published in the New England Journal of Medicine and Annual Review of Medicine.
A graduate of Case Western Reserve University, School of Medicine, Cleveland, OH, he served his residence at Cleveland Metropolitan General Hospital, Cleveland, OH followed by a fellowship in medical oncology at University of Southern California, Los Angeles, CA. Dr. Chlebowski received his Ph.D. from Case Western Reserve University School of Medicine, Department of Reproductive Biology. In addition to his role at REI as principal investigator, Dr. Chlebowski serves on the steering committee, Schering-Plough Research Institute, Executive Committee of the Board of Directors, REI and steering committee, Women’s Health Initiative. He also serves as Co-Chair, Executive Committee, National Cancer Institute Women’s Intervention Nutrition Study and has served on the AIDS Clinical Trial Group, National Institutes of Health, 1995 to 1999.
Harbor-UCLA Research & Education Institute, located on the campus of Harbor-UCLA Medical Center in Torrance, California, is a leading independent, not-for-profit biomedical research institute with an international reputation for scientific discovery, the training of physician-scientists and the provision of community service programs. It is an affiliate of both the UCLA School of Medicine and the Harbor-UCLA Medical Center and has an annual budget of $58 million. The Institute traces its roots back to 1952, when researchers and physicians joined forces with the UCLA School of Medicine on the campus of what was then known as Harbor General Hospital to conduct a handful of research studies. Today, more than 1,000 research projects and clinical trials are being conducted at REI, advancing scientific understanding in order to improve medical outcomes and promote innovation in such areas as autoimmune disorders, cancer, cardiovascular disease, developmental disorders and other pediatric health problems, diabetes, infectious disease, inherited disorders, male contraception, vaccine evaluation and research, and various aspects of women’s health.
Harbor-UCLA REI Contact:
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