How Exercise Increases Cancer Survival

Scientists have known for years that maintaining an active lifestyle and taking time to exercise helps prevent cancer. But whether exercise improves survival rates for people who already have cancer was unclear. Now, a first-of-its kind international clinical trial provides the strongest clinical evidence to date that regular physical activity can help keep cancer at bay and prolong life.

The Colon Health and Life-Long Exercise Change or CHALLENGE trial, led by the Canadian Cancer Trials Group, enrolled 889 colon cancer patients across 55 treatment centers. Patients were randomized to a health education control group or a 3-year exercise intervention.

After nearly eight years of follow-up, the results were striking: patients in the exercise group had an overall 37% reduction in mortality compared to those in the health education control group. The overall survival was 90.3% in the exercise group versus 83.2% in the group that received educational materials alone.

Dr. Melinda Irwin, PhD, MPH, associate dean of research and the Susan Dwight Bliss Professor of Epidemiology (Chronic Diseases) at the Yale School of Public Health and deputy director of the Yale Cancer Center, is a leading authority on exercise, nutrition, and cancer. She recently took a moment to discuss the CHALLENGE trial results and what they mean for patients diagnosed with cancer.

Dr. Melinda Irwin: While dozens of observational studies have reported that physical activity after a colon cancer diagnosis is linked to a lower risk of recurrence and death, there has not been definitive evidence from a large, randomized trial of the impact of exercise on survival among patients with colon cancer. The CHALLENGE trial showed that exercise significantly reduced the risk of recurrence, new cancer diagnoses, and mortality. In sum, this first trial of exercise on disease-free survival in patients with colon cancer provides definitive evidence that exercise offers additional benefits to overall survival beyond surgery and chemotherapy, while also enhancing quality of life. The magnitude of benefit is comparable to that of many approved cancer therapies.

MI: While current oncology guidelines already recommend physical activity before, during, and after treatment, few adults—whether healthy or diagnosed with cancer— meet the recommended 2.5 hours per week of moderate-intensity activity, such as brisk walking. While research on how to identify the best strategies for integrating exercise counseling into oncology care is needed, we should not wait. Clinicians can refer patients to community-based exercise programs and utilize or adapt existing services like cardiac rehabilitation. Trained exercise counselors should be embedded within oncology care teams, with services covered by insurance. As oncology continues to advance, exercise must become a standard part of care.

MI: If they are currently exercising, then keep it up! If they are not exercising, then starting a walking program would be best. Many people have mobile phones with a health app installed on the device. This health app includes information on the number of steps you walk per day. If, for example, you walk around 5000 steps per day, then try to increase that number by 1,000 steps, which is about half a mile. If you can increase the amount by 2,000 steps, or one mile per day, until you get to around 8000-10,000 steps per day, that’s even better.

Also trying to include twice-weekly strength training into your monthly routine is important. There are many apps that provide videos of exercises you can do at home to maintain or increase your strength.

The bottom line is that any amount of physical activity is more beneficial than no physical activity.

The full study appears in the New England Journal of Medicine, along with an editorial written by Dr. Irwin: Extending Cancer Survival with Exercise — Time for Oncology to Act | New England Journal of Medicine.