- First study to examine the association of physical activity with patient survival in advanced, metastatic colorectal cancer
- Even low-intensity exercise was associated with a reduction in progression free survival
BOSTON - 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.
Even low-intensity exercise, such as walking four or more hours a week, was associated with a nearly 20 percent reduction in cancer progression or death over the course of the six-year study, said researchers from Dana-Farber Cancer Institute and Brigham and Women's Hospital, reporting in the Journal of Clinical Oncology. 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 (PFS)," said Jeffrey A. Meyerhardt, MD, MPH, of Dana-Farber, senior author of the study. "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 Brendan Guercio, MD, first author of the study which was conducted while he was working as a hospitalist at Brigham and Women's. "Total physical activity equivalent to 30 or more minutes of moderate daily activity was associated with a 27 percent reduction in severe treatment-related toxicities."
Previous studies have found that regular exercise can reduce the risk of disease recurrence and death from colon cancer that has not metastasized to other parts of the body. 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 3 study of chemotherapy for advanced colorectal cancer conducted by the Alliance for Clinical Trials in Oncology and sponsored by the National Cancer Institute. Within a month after beginning treatment, patients were invited to complete a questionnaire about their average physical activity over the previous two 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. Non-vigorous activities included walking, climbing stairs, or yoga.
Analysis of the data revealed a statistically significant difference in PFS - the length of time after the patient completed the questionnaire before the cancer progressed or the person died. The difference in PFS was almost 20 percent in favor of those who exercised more.
Meyerhardt added that 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."
The analysis also found that patients who engaged in 18 or more MET-hours per week of activity had a 15 percent improvement in overall survival (death from any cause) than patients who engaged in less than three MET-hours per week of activity. However, that difference was not statistically significant, meaning it could have resulted from chance.
The study authors noted that all patients in the study were being treated with chemotherapy and the study results do not suggest that exercise should be substituted for chemotherapy or any other standard therapy.
Funding for this study was provided by: the National Institutes of Health under Award Numbers U10CA180821 (Alliance Chairman's Grant to the Alliance for Clinical Trials in Oncology) and U10CA180882 (Alliance Statistics and Data Center Grant to the Alliance for Clinical Trials in Oncology), U10CA180791, U10CA180795, U10CA180826, U10CA180836, U10CA180838, U10CA180850, U10CA180867, UG1CA189858, UG1CA189869; U10CA180820 (ECOG-ACRIN); U10CA180888 and U10CA180830 (SWOG); R01CA149222, R01CA169141, R01CA118553, K07CA197077, R01CA205406, and CA180820; and the Stand-Up-to-Cancer Colorectal Dream Team Grant. Also supported in part by funds from Bristol-Myers Squibb, Genentech, Eli Lily and Company, Pfizer, and Sanofi. Meyerhardt is supported by the Douglas Gray Woodruff Chair in Colorectal Cancer Research Fund, the Guo Shu Shi Fund, Anonymous Family Fund for Innovations in Colorectal Cancer, and the George Stone Family Foundation.
Dana-Farber Cancer Institute is one of the world's leading centers of cancer research and treatment. It is the only center ranked in the top 4 of U.S. News and World Report's Best Hospitals for both adult and pediatric cancer care.
Dana-Farber's mission is to reduce the burden of cancer through scientific inquiry, clinical care, education, community engagement, and advocacy. We provide the latest in cancer for adults through Dana-Farber/Brigham and Women's Cancer Care and for children through Dana-Farber/Boston Children's Cancer and Blood Disorders Center.
Dana-Farber is dedicated to a unique and equal balance between cancer research and care, translating the results of discovery into new treatments for patients locally and around the world.
About the Alliance for Clinical Trials in Oncology
The Alliance for Clinical Trials in Oncology develops and conducts clinical trials with promising new cancer therapies and utilizes the best science to develop optimal treatment and prevention strategies for cancer, and research methods to alleviate side effects of cancer and cancer treatments. The Alliance is part of the National Clinical Trials Network (NCTN) sponsored by the National Cancer Institute (NCI) and serves as a research base for the NCI Community Research Oncology Program (NCORP). The Alliance comprises nearly 10,000 cancer specialists at hospitals, medical centers, and community clinics across the United States and Canada. To learn more about the Alliance, visit http://www.