Moderate exercise can improve outcomes for patients with metastatic colorectal cancer, study shows

Patients with metastatic colorectal cancer may be able to lower the risk of the disease worsening, and improve their chances of survival, if they engage in moderate daily exercise, according to new research by investigators at Dana-Farber Cancer Institute.

The results of the research, presented today at the American Society of Clinical Oncology's Gastrointestinal Cancer Symposium, contradict the widespread belief that, because the prognosis for patients with metastatic cancer is often poor, there is little benefit to be gained from exercise, the study authors said.

Research has consistently shown that increased physical activity can improve outcomes for patients with non-metastatic colorectal cancer," said the study's lead author, Brendan Guercio, MD, a medical student studying at Dana-Farber at the time the research was completed and now a medical resident at Brigham and Women's hospital. "This is the first study to indicate that more exercise may benefit patients with metastatic forms of the disease."

In the study, 1,231 patients participating in a clinical trial of chemotherapy for metastatic colorectal cancer completed a questionnaire on how many hours a week they engaged in various leisure-time activities, ranging from gardening, to more strenuous pursuits such as jogging, hiking, and bicycling. Researchers then tracked respondents' health for the next three and a half years.

The investigators found that during that period, patients who engaged in moderate physical activity for thirty minutes a day had a 16 percent lower risk of the disease worsening than did those who didn't exercise or exercised less. The 30 minutes a day group also had a 19 percent lower risk of dying from any cause than did the others.

It isn't clear, from a physiological standpoint, how exercise confers this benefit, Guercio said. Laboratory research has found that insulin may affect the biology of colorectal cancer, suggesting that it may be more aggressive in people with high levels of insulin or insulin resistance. Regular exercise can lead to lower insulin levels.

"Patients consistently ask regarding other things to consider in addition to standard treatments, and this is the first prospective data that I am aware for the role of exercise impacting survival in a metastatic colorectal cancer population," said Jeffrey Meyerhardt, MD, MPH, clinical director of the Gastrointestinal Cancer Center at Dana-Farber and senior author of the study.