San Francisco, CA—Daily moderate physical activity can improve outcomes in patients with metastatic colorectal cancer (CRC).
In a large clinical trial, patients who reported engaging in physical activity equivalent to ≥30 minutes of moderate exercise daily at the time of chemotherapy initiation had a 19% reduction in mortality, and a 16% reduction in disease progression, said lead investigator Brendan Guercio, MD, resident physician, Brigham and Women’s Hospital, Boston, MA, at the 2017 Gastrointestinal Cancers Symposium.
The data are the first evidence of a link between exercise and outcomes in patients with CRC and distant metastases. Previous studies have consistently shown a link between regular exercise and improved outcomes in patients with early-stage CRC without distant metastases.
The findings suggest that “even light activities that many metastatic cancer patients might be able to participate in could be associated with improved outcome,” said Dr Guercio.
Patients who are physically active tend to tolerate chemotherapy better, he noted, adding that patients with CRC often seek more information about lifestyle changes that may improve their outcomes.
The analysis included 1231 patients who were enrolled in the phase 3 CALGB 80405 trial of chemotherapy for metastatic CRC. At the time of chemotherapy initiation, patients completed questionnaires that included self-reports on 9 leisure-time physical activities and their average walking pace. The total metabolic equivalent task-hours per week were determined by the responses.
Compared with the least physically active patients (ie, those who engaged in less than 3 metabolic equivalent task-hours per week of activity), those who engaged in ≥18 metabolic equivalent task-hours per week, equivalent to ≥30 minutes each day of moderate physical activity (ie, walking, cleaning, or gardening), had an adjusted hazard ratio for overall survival of 0.81 (P = .03) and for progression-free survival of 0.84 (P = .03).
In an exploratory analysis, “we also found that individuals walking 4 or more hours per week had a greater than 20% improvement in overall survival. Walking pace, on the other hand, was not associated with the outcomes we assessed in this study [progression-free survival and overall survival],” said Dr Guercio.
In addition, ≥5 hours per week of nonvigorous activity (eg, walking or yoga) was associated with a 25% improvement in overall survival.
When adjusting for confounders, such as comorbidities, weight change over the previous 6 months, performance status, body mass index, type of chemotherapy received, tumor KRAS status, sex, and age, the association between moderate activity and outcomes remained significant, said Dr Guercio.
Randomized controlled trials and more prospective clinical studies are needed to confirm these associations in metastatic CRC, he added. An ongoing randomized clinical trial is comparing survival in patients who exercise during treatment and those who do not.
“Physical activity can be difficult for patients with advanced colorectal cancer, but this study shows that even a small amount of exercise may make a big difference. It’s important to help our patients find ways to incorporate moderate exercise into their daily lives—regardless of the stage of their disease,” added American Society of Clinical Oncology expert Nancy Baxter, MD, PhD, Chief, Department of General Surgery, St. Michael’s Hospital, Toronto.