|For immediate use
Sept. 11, 2006 -- No. 413
Exercise may increase breast cancer survival for young women
CHAPEL HILL -- Overweight or obese young women who report moderate or vigorous physical activity during the year prior to their breast cancer diagnosis have increased five-year survival, researchers from the University of North Carolina at Chapel Hill have found.
The results show a modest improvement in long-term survival for all women ages 20 to 54 years old who were active just before breast cancer diagnosis. The effects of physical activity were most significant for women with a body mass index greater than 25.
Understanding the link between breast cancer and lifestyle factors such as exercise can help explain variation in survival rates among women, said Dr. Page Abrahamson, who conducted the study as a graduate student in UNC's School of Public Health.
"Disease stage and tumor grade are estimated to only explain about 20 percent of variation in survival. Identifying other factors that affect prognosis will help us identify women at increased risk of death and provide more ways for patients to enhance their survival," said Abrahamson, now a postdoctoral researcher at the Fred Hutchinson Cancer Center in Seattle, Wash.
The study appears in the Oct. 15 issue of the journal Cancer. Funding was provided by the National Cancer Institute and Public Health Service grants from National Institutes of Health. Dr. Marilie Gammon of UNC's Lineberger Comprehensive Cancer Center, a professor of epidemiology in UNC's School of Public Health, served as Abrahamson's thesis advisor and is a study co-author.
To measure the effects of physical activity on breast cancer survival, Abrahamson and her colleagues followed 1,264 women diagnosed with invasive breast cancer between 1990 and 1992 living in metropolitan Atlanta or a five-county region of New Jersey. Interviewers asked participants to report physical activity levels at ages 12 to 13 years old, 20 years old and the year before diagnosis.
Physical activity at the two earlier ages did not confer a survival advantage, the researchers found. In the year before diagnosis, physical activity was not associated with survival among women who were underweight or at ideal weight. The results also did not show a link between reduced mortality and high level of average lifetime physical activity.
Abrahamson said physical activity may influence breast cancer prognosis in the same way it affects the odds of developing breast cancer. These include the possible benefits provided by physical activity such as decreased estrogen exposure, enhanced immune function, lower body fat or reduced insulin resistance.
Study co-authors are from: Emory University, Atlanta, Ga.; Mount Sinai School of Medicine, New York, N.Y.; the federal Centers for Disease Control and Prevention, Atlanta, Ga.; Fred Hutchinson Cancer Research Center, Seattle, Wash.; and the National Cancer Institute, National Institutes of Health, Bethesda, Md.
Notes: Dr. Abrahamson may be reached at (206) 667-5491 or firstname.lastname@example.org
Dr. Gammon may be reached at (919) 966-7421 or email@example.com
UNC Lineberger contact: Dianne Shaw, (919) 966-7834 or firstname.lastname@example.org
Fred Hutchinson contact: Kristen Woodward, (206) 667-5095 or email@example.com
UNC News Services contact: Becky Oskin, (919) 962-8596 or firstname.lastname@example.org