CHICAGO, June 4, 2007 -- Women on tamoxifen therapy who reported having hot flashes were less likely to develop recurrent breast cancer than those who did not report hot flashes, according to a study from the Moores Cancer Center at the University of California, San Diego (UCSD). Moreover, hot flashes were a stronger predictor of outcome than age, hormone receptor status or even how advanced the breast cancer was at diagnosis.
The study results were presented at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago today.
"Hot flashes are a very common and disruptive problem in breast cancer survivors," said the study's first author Joanne Mortimer, M.D., medical director of the Moores Cancer Center and professor of medicine with the UCSD School of Medicine. "About two-thirds of women with breast cancer say hot flashes compromise their quality of life. The most common request for additional treatment we get is for relief from these symptoms."
The study was based upon data from the comparison group of the Women's Healthy Eating and Living (WHEL) study – a multi-site randomized trial of the impact of a diet high in vegetables, fruits and fiber, and low in fat on the recurrence of breast cancer. The WHEL participating institutions are University of California, San Diego and Davis, Stanford University, Kaiser Permanente in Oakland and Portland, University of Arizona at Tucson, and the University of Texas MD Anderson Cancer Center in Houston.
Of the 1,551 women with early-stage breast cancer who were randomized to the comparison group of the WHEL study, more than half (864, or 56 percent) were taking tamoxifen, and more than three-quarters of those (674, or 78 percent) reported hot flashes.
Cancer recurrence among women who reported hot flashes was about 12.9 percent, compared with 21 percent for women not reporting hot flashes. These data were consistent across all years of follow-up, regardless of age or menopausal status.
"This study provides the first evidence that hot flashes may be an indicator of a better prognosis in women with early stage breast cancer," said the study's senior author, John P. Pierce, Ph.D, director of the Cancer Prevention and Control Program at the Moores UCSD Cancer Center. "Our data support the possibility of a significant association between hot flashes and disease outcome."
As a next step, the researchers plan to further study the relationship between hot flashes and breast cancer progression by measuring the tamoxifen metabolites in breast cancer survivors.
Besides Mortimer and Pierce, authors on the paper are Shirley W. Flatt, M.S., Barbara A. Parker, M.D., Linda Wasserman, M.D., Ph.D., and Loki Natarajan, Ph.D., of the Cancer Prevention and Control Program, Moores UCSD Cancer Center; and Ellen B. Gold of the Department of Public Health Sciences at University of California, Davis. This work was supported by the Walton Family Foundation and a National Cancer Institute grant.
Founded in 1979, the Moores UCSD Cancer Center is one of just 40 centers in the United States to hold a National Cancer Institute (NCI) designation as a Comprehensive Cancer Center. As such, it ranks among the top centers in the nation conducting basic, translational and clinical cancer research, providing advanced patient care and serving the community through innovative outreach and education programs.