Movement as medicine: Strengthening colon cancer outcomes through physical activity
Research evidence shows that staying active is a vital tool for colon cancer recovery and long-term health.

For many patients with Stage 2 or 3 colon cancer, completing adjuvant chemotherapy is a major milestone—but it is often a finish line that leads to a daunting new start. While medical advancements have significantly improved initial treatment success, the risk of recurrence remains a persistent shadow for survivors.

This transition point is where Dr. Kerry Courneya from the University of Alberta and Dr. Christopher Booth from Queen’s University helped co-lead an international clinical trial conducted by the Canadian Cancer Trials Group (CCTG). Through the CO.21 CHALLENGE trial, they demonstrated that movement is far more than a way to improve quality of life—it is a life-saving intervention.

The CHALLENGE trial followed survivors over a 17-year period. Participants were enrolled shortly after completing chemotherapy and split into two groups: one received standard health education, while the other engaged in a three-year structured exercise program.

The results were groundbreaking. Patients in the exercise group saw a 28% reduction in the risk of cancer recurrence or a new cancer and a 37% lower risk of death compared to the control group. Interestingly, the data suggested that women might gain even more benefit, partly because the exercise also reduced the risk of developing a new primary breast cancer.

One of the most significant contributions of this research is a better understanding of the barriers to movement. "Patients experience a lot of fatigue after chemo and it feels like rest should be the best approach," Dr. Courneya explained. "Exercise is counterintuitive as a management strategy for fatigue."

To address this barrier, the program was designed for flexibility and long-term maintenance:

• Aerobic exercise: While patients could choose their activity, walking was the most popular.
• Scalability: Patients chose their own frequency and duration to ensure the habit stuck for the full three years.
• Professional support: Ongoing contact with exercise specialists helped survivors navigate the return to work and other life responsibilities.

For Linda van Delden, post-chemo reality was a heavy sense of lethargy, but she was determined to feel like herself again. Working with an exercise specialist was her turning point. "I was tired of feeling sick," Linda recalls. She had to accept that her body had changed while also managing new knee pain and realizing she might not return to her former "running shape."

The accountability of the study and her structured exercise plan kept her consistent even when life got busy. "I can still hear the exercise specialist in my head saying slow down, straighten those shoulders, and don’t extend too far." For Linda, the realization was simple but profound—on days when she felt too tired for a full workout, even ten minutes of gardening or playing with her grandkids provided the spark she needed.

While the 28% reduction in recurrence or new cancer is a massive clinical win, the qualitative transformation in patients is equally profound. For many survivors, everything about the cancer journey feels "abnormal." Exercise provides a psychological bridge back to their former selves.

By improving body image and self-esteem while reducing anxiety and depression, physical activity gives survivors a sense of control. It makes them feel like their body is no longer a site of illness, but a source of strength.

This global breakthrough was decades in the making. Dr. Courneya’s ability to co-lead a trial of this magnitude was built on early and sustained research investment from the Canadian Institutes of Health Research (CIHR), among other funders. CIHR investments, from an Investigator Award early in his career to a 2018 Foundation Grant titled Physical activity and cancer outcomes: Generating practice-changing evidence, provided the infrastructure and protected research time needed to advance promising pilot studies toward the large-scale international phase 3 trial that ultimately transformed the standard of care. The Canadian Cancer Society was one of the key funders of the trial.

Today, organizations like ESMO are already updating clinical practice guidelines to include exercise for Stage 2 and 3 colon cancer. For survivors, these findings offer more than just a lower risk percentage—they offer a clear roadmap to a healthier, more active, and empowered future.

At a glance

Issue

While completing chemotherapy is a milestone for Stage 2 and 3 colon cancer survivors, the risk of recurrence remains a significant threat. Post-treatment, many patients struggle with chronic fatigue and a lack of clear guidance on lifestyle interventions that can actively prevent the cancer from returning or improve their long-term survival.

Research

Dr. Kerry Courneya and Dr. Christopher Booth co-led the international CO.21 CHALLENGE trial through the Canadian Cancer Trials Group. This 17-year study proved that a structured exercise program reduces the risk of cancer recurrence or new cancer by 28% and the risk of death by 37%, establishing movement as a life-saving clinical intervention.