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. Weve 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
Contact: Barbara Kerr
Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center (LA BioMed)