While several observational studies have demonstrated the anti-cancer benefits of exercise, this first-of-its-kind international trial provides more definitive, high-level evidence that consistent physical activity can keep colorectal cancer from coming back.
“These results now provide us with a clear answer: An exercise program that includes a personal trainer will reduce the risk of recurrent or new cancer, make you feel better, and help you live longer,” Dr. Booth said.
1 in 3 High-Risk Colon Cancer Survivors May Experience Recurrence
After completing surgery and chemotherapy, nearly one-third of people with high-risk colon cancer may eventually experience recurrence of their disease. After recurrence, colon cancer can be harder to treat.
In this study, researchers evaluated how following a structured exercise program might further reduce the risk of recurrent or new cancer compared with just being advised to exercise.
Personalized Exercise Guidance Makes a Difference
This clinical trial involved 889 individuals enrolled between 2009 and 2023, who completed surgery followed by chemotherapy for high-risk stage 2 and stage 3 colon cancer. Participants were 61 years old on average, just over half were female, and 90 percent had stage 3 cancer. Although patients were from around the world, most were from Canada and Australia.
Half the patients were randomly assigned to participate in a three-year structured exercise program involving moderate-intensity aerobic activities like walking, biking, swimming, or exercising on an elliptical machine, while the other half were given the standard care, which involved receiving educational materials promoting physical activity and healthy eating.
As part of the structured exercise program, participants worked with a personal trainer. For the first six months, they met with the trainer twice a month for coaching sessions. After learning the type of aerobic exercise each person enjoyed, the trainer gave each one an “exercise prescription” to hit a specific amount of activity.
After six months, participants met with their trainers once a month, with additional sessions available for extra support if needed. The goal of the program was to sustain the change in physical activity.
While people in both groups improved their physical function over the years of the intervention, results were significantly better for people who worked with a trainer.
At five years, the disease-free survival rate was 80 percent in the structured exercise program group, compared with 74 percent in the standard care group. That meant people in the structured exercise group lowered their risk of new or recurring cancer by 28 percent.
After eight years, overall survival was 90 percent for people in the structured exercise group, compared with 83 percent in the standard care group. That equated to a 37 percent lower risk of death for the people in the structured exercise group.
Having a Solid Plan Made Participants More Likely to Stick With Exercise
“The structured exercise program had a profound impact on cancer survival outcomes, while also improving fundamental physiologic basis and functional capacity, improving measurable quality of life, and thereby impacting overall well-being, with minimal adverse effects,” says Y. Nancy You, MD, a professor of colon and rectal surgery at The University of Texas MD Anderson Cancer Center in Houston, who was not involved in the research.
In the structured exercise group, 19 percent reported side effects that affected their bones, joints, and muscles, such as muscle strains or bone fractures, compared with 12 percent in the standard care group.
John Marshall MD, chief medical consultant of the Colorectal Cancer Alliance and director of the Ruesch Center for the Cure of Gastrointestinal Cancers at Georgetown University in Washington, DC, notes that although the intervention was just three years, the benefits extended far beyond that.
“The findings suggest that if you start a structured exercise program you’re more apt to stick with it on your own. It becomes part of your day-to-day habits,” says Dr. Marshall, who was not a study author.
Exercise May Be Equivalent to Some Chemo Drugs in Benefit
“The study shows that exercise has an impact as large and or even larger than some chemotherapy drugs have had in terms of overall outcome for patients,” he says. “This is a remarkable result. This study justifies our recommendations and quantifies the magnitude of benefit.”
As to why exercise may help fight cancer, the authors suggest that it may have positive effects on metabolism, inflammation, and immune function, although these factors were not examined in this study.
“Now we need to ask insurers to cover our personal trainers,” says Marshall. “They will cover the chemo, but they won’t cover the personal trainer when in fact, the personal trainer may produce better outcomes than the drugs.”