Patients with metastatic colon cancer who exercise may live longer, according to an analysis of the CALGB/SWOG 80405 trial presented at the 2017 Gastrointestinal Cancers Symposium.1 According to the authors, this is the first study to demonstrate an association between physical activity and survival in metastatic colorectal cancer.
In the CALGB (formerly the Cancer and Leukemia Group B and now Alliance)/SWOG 80405 study, cetuximab (Erbitux) and bevacizumab (Avastin) conferred similar benefits as first-line treatment with chemotherapy for KRAS wild-type metastatic colorectal cancer.2 Additional prospective analyses of this cohort now show that increased physical activity was associated with longer overall and progression-free survival.
While exercise is by no means a substitute for chemotherapy, patients may experience a wide range of benefits from as little as 30 minutes of exercise a day.— Brendan J. Guercio, MD
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Patients who engaged in at least 5 hours of nonvigorous physical activity per week had a 25% reduction in the hazard for death from any cause. Similarly, walking 4 or more hours per week was associated with a 20% improvement in the hazard for death from any cause, according to Brendan J. Guercio, MD, of Brigham and Women’s Hospital and Dana-Farber Cancer Institute in Boston.
“In this prospective cohort study of metastatic colorectal cancer patients, increasing total physical activity was associated with improved progression-free survival and overall survival,” said Dr. Guercio. “Greater walking duration—but not walking pace—and nonvigorous activity were also associated with improved overall survival. These associations remained statistically significant after adjusting for other potential predictors of patient outcome.”
Moderator of a press briefing on this study, Nancy Baxter, MD, PhD, of the University of Toronto and St. Michael’s Hospital, said that the level of activity was reasonable. “This study shows that even a small amount of exercise may make a big difference,” she commented. “It’s important to help our patients find ways to incorporate moderate exercise into their daily lives, regardless of the stage of their disease.”
Other studies have also concluded that physical activity can improve survival in patients with nonmetastatic colorectal cancer and that the risk of developing colorectal cancer decreases as physical activity increases. In other tumor types, similar findings have been made, the authors noted.
The current study was a review of data from a prospective cohort study nested within the 1,231-patient CALGB/SWOG 80405 randomized trial. Patients completed a baseline activity questionnaire that covered nine leisure-time activities and the study participant’s average walking pace. The primary outcome of both the main trial and the cohort study was overall survival.
Dr. Guercio emphasized that the benefits accrued even with nonvigorous activity, such as walking or yoga. The results remained significant after investigators controlled for confounders, including comorbidities, weight change over the previous 6 months, performance status, body mass index, chemotherapy regimen, tumor KRAS status, patient sex, and patient age. “We wanted to see whether physical activity helped make people healthier or our findings merely indicated that sicker individuals exercised less,” he explained.
“These findings suggest that it doesn’t take a lot of physical activity to improve outcomes,” said Dr. Guercio. “While exercise is by no means a substitute for chemotherapy, patients may experience a wide range of benefits from as little as 30 minutes of exercise a day.” ■
Disclosure: Dr. Guercio reported no potential conflicts of interest.
1. Guercio BJ, et al: Associations of physical activity with survival and progression in metastatic colorectal cancer. 2017 Gastrointestinal Cancers Symposium. Abstract 659. Presented January 21, 2017.
2. Venook AP, et al: CALGB/SWOG 80405. 2014 ASCO Annual Meeting. Abstract LBA3.