Does Exercise Improve Outcomes in Patients With Metastatic Colorectal Cancer?
Patients with metastatic colorectal cancer who engaged in moderate exercise while undergoing chemotherapy tended to have delayed progression of their disease and fewer severe side effects from treatment, according to the results of a new study published by Guercio et al in the Journal of Clinical Oncology.
Even low-intensity exercise, such as walking 4 or more hours a week, was associated with a nearly 20% reduction in cancer progression or death over the course of the 6-year study. The analysis hinted at a possible lengthening of survival in patients who reported greater physical activity, but the data were not statistically significant.
“What we found was that people who engaged in some type of physical activity had a statistically significant improvement in progression-free survival,” said senior study author Jeffrey A. Meyerhardt, MD, MPH. “While there may also be an impact on overall survival, it was not statistically significant—and should be studied further.”
“Physically active patients in our study also appeared to tolerate chemotherapy better,” said first study author Brendan Guercio, MD. “Total physical activity equivalent to 30 or more minutes of moderate daily activity was associated with a 27% reduction in severe treatment-related toxicities.”
Methods
Previous studies have found that regular exercise can reduce the risk of disease recurrence and death from colon cancer that has not metastasized. Researchers say this is the first study to examine associations of physical activity with survival in advanced, metastatic colorectal cancer.
Patients participated in a phase III study of chemotherapy for advanced colorectal cancer conducted by the Alliance for Clinical Trials in Oncology and sponsored by the National Cancer Institute. Within 1 month after beginning treatment, patients were invited to complete a questionnaire about their average physical activity over the previous 2 months. The final number of participants included 1,218 patients. While the data are significant, further research with a randomized prospective trial will help validate the results, the researchers said.
Based on the patients’ descriptions, researchers quantified their physical activity in terms of metabolic equivalent task (MET)-hours per week, a standard measure used in research studies of exercise. Vigorous activity was defined as any activity requiring six or more METs, such as running, biking, tennis, skiing, or lap swimming. Nonvigorous activities included walking, climbing stairs, or yoga.
Results
Analysis of the data revealed a statistically significant difference in progression-free survival. The difference in progression-free survival was almost 20% in favor of those who exercised more.
“The findings help justify encouraging patients to exercise and referring patients to physical therapists or programs like the YMCA Livestrong program that does small-group training for patients with cancer,” said Dr. Meyerhardt.
The analysis also found that patients who engaged in 18 or more MET-hours per week of activity had a 15% improvement in overall survival compared with patients who engaged in less than 3 MET-hours per week of activity. However, that difference was not statistically significant.
The authors concluded, “Among patients with metastatic colorectal cancer in Cancer and Leukemia Group B (Alliance)/SWOG 80405, association of physical activity with overall survival was not statistically significant. Greater physical activity was associated with longer [progression-free survival] and lower adjusted risk for first grade 3 or greater treatment-related adverse events.”
Disclosure: Funding for this study was provided by the National Institutes of Health, the Stand Up to Cancer Colorectal Dream Team Grant, Bristol-Myers Squibb, Genentech, Eli Lilly and Company, Pfizer, and Sanofi. For full disclosures of the study authors, visit jco.ascopubs.org.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
