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 white women. Published early online 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 US Department of Health and Human Services, as well as the American Cancer Society, recommends that adults engage in at least 150 minutes of moderate-intensity physical activity or 75 minutes of vigorous-intensity physical activity (or an equivalent combination thereof) each week for general health benefits and for chronic disease prevention and management.
Because it’s important to understand whether there is capacity for improvement in the physical activity levels of women with breast cancer, Brionna Hair, a doctoral candidate in epidemiology at the University of North Carolina at Chapel Hill, 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 aged 20 to 74 years who were diagnosed with invasive breast cancer between 2008 and 2011 in 44 counties of North Carolina.
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). Ms. Hair noted that it’s important to realize that African-American women experience higher mortality from breast cancer than 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,” said Ms. Hair.
Data for this research was provided by the latest phase of the Carolina Breast Cancer Study, the largest-ever population-based study of breast cancer in North Carolina and one of the largest studies of African American women in the world. Launched in 1993, CBCS aims to improve understanding of breast cancer, including why the disease’s fatality rate is higher in African-American women. Phase III focuses specifically on how treatment decisions, access to care, and financial or geographic barriers impact breast cancer outcomes and whether these outcomes are predictable or altered by genetic breast cancer subtypes. CBCS is led by faculty within the UNC Lineberger Comprehensive Cancer Center, UNC Gillings School of Global Public Health and UNC School of Medicine with funding from the University Cancer Research Fund, the National Cancer Institute, UNC Breast SPORE and Susan G. Komen for the Cure®.