June 9, 2014
Physical activity after breast cancer diagnosis has been linked with prolonged survival and improved quality of life, but most participants in a large breast cancer study did not meet national physical activity guidelines after they were diagnosed. Moreover, African-American women were less likely to meet the guidelines than were white women.
Published online June 9 in Cancer, a peer-reviewed journal of the American Cancer Society, the findings indicate that efforts to promote physical activity in breast cancer patients may need to be significantly enhanced.
The study, “Racial differences in physical activity among breast cancer survivors: implications for breast cancer care,” was led by Brionna Hair, epidemiology doctoral student at the UNC Gillings School of Global Public Health.
The U.S. Department of Health and Human Services and the American Cancer Society recommend that adults engage weekly in at least 150 minutes of moderate-intensity physical activity or 75 minutes of vigorous-intensity physical activity (or an equivalent combination thereof) for general health benefits and chronic disease prevention and management.
Because it is important to understand whether there is capacity for improvement in the physical activity levels of women with breast cancer, Hair and her colleagues examined levels of and changes in physical activity following breast cancer diagnosis, overall and by race, in a population-based study of breast cancer patients. The study assessed pre- and post-diagnosis physical activity levels in 1,735 women ages 20 to 74 years who were diagnosed with invasive breast cancer between 2008 and 2011 in 44 North Carolina counties.
The researchers found that only 35 percent of breast cancer survivors met current physical activity guidelines post-diagnosis. A decrease in activity approximately six months after diagnosis was reported by 59 percent of patients, with the average participant reducing activity by 15 metabolic equivalent hours—equivalent to about five hours per week of brisk walking. When compared with white women, African-American women were about 40 percent less likely to meet national physical activity guidelines post-diagnosis, although their reported weekly post-diagnosis physical activity was not significantly different from that of white women (12 vs. 14 metabolic equivalent hours). Hair noted that African-American women experience higher mortality from breast cancer than do other groups in the United States.
“Medical care providers should discuss the role physical activity plays in improving breast cancer outcomes with their patients, and strategies that may be successful in increasing physical activity among breast cancer patients need to be comprehensively evaluated and implemented,” Hair said.
Other Gillings School co-authors include epidemiology applications specialist Chiu-Kit Tse, and Andrew Olshan, PhD, Barbara Sorenson Hulka Distinguished Professor of Cancer Epidemiology and epidemiology department chair. Other co-authors include Mary Beth Bell, project director at the UNC Lineberger Comprehensive Cancer Center (UNC-LCCC), and Sandra Hayes, PhD, associate professor of public health and social work at Queensland University of Technology, in Brisbane, Australia. Olshan also is research professor of otolaryngology/head and neck surgery in the UNC School of Medicine, director of the developmental susceptibility research core at the UNC Center for Environmental Health and Susceptibility, and interim associate director for population sciences at UNC-LCCC.