A landmark international clinical trial has provided definitive evidence that structured exercise programs significantly improve survival outcomes for colon cancer patients, marking a potential paradigm shift in cancer treatment protocols. The study, published in the New England Journal of Medicine and presented at the American Society of Clinical Oncology annual conference, represents the first clinical trial specifically designed to determine whether exercise can improve cancer survival.
Groundbreaking Trial Results
The CO.21 Challenge trial, conducted over 17 years from 2009 to 2024, enrolled 889 patients diagnosed with Stage 3 or high-risk Stage 2 colon cancer who had completed surgery and chemotherapy. Participants were randomly assigned to either a structured exercise program with an exercise therapist over three years or standard health education materials about physical activity and nutrition benefits.
The results demonstrated remarkable improvements in patient outcomes. Those assigned to the structured exercise program experienced a 37% lower risk of death and a 28% lower risk of cancer recurrence or developing new primary cancers compared to the control group receiving only educational materials.
Exercise as Cancer Treatment
"Our findings show that exercise is no longer just a quality-of-life intervention for cancer patients that can be offered when and where possible," said study co-chair Dr. Kerry Courneya, a professor of kinesiology at the University of Alberta and Canada Research Chair in Physical Activity and Cancer. "It is a treatment for colon cancer that must be made available to all patients."
The exercise program allowed participants to choose their preferred forms of moderate-intensity exercise, ranging from walking to pickleball, with the goal of adding 2.5 hours of exercise per week to their regular activity schedule. This personalized approach helped ensure sustainability and adherence to the program.
Clinical Impact and Implementation
Dr. Christopher Booth, study co-chair, medical oncologist at Kingston Health Sciences Centre and professor of oncology at Queen's University, emphasized the transformative nature of these findings. "This is the first clinical trial in the world designed to answer whether exercise can improve cancer survival, and the results are clear," he said. "The next step is to put this into practice. That means health systems will need to invest in behaviour support programs as part of standard care."
The researchers noted that the scale of benefit from exercise is, in some cases, superior to what is offered through many standard cancer drug regimens, while providing these benefits in addition to those from surgery and chemotherapy.
Patient Experience
Terri Swain-Collins, a 62-year-old trial participant diagnosed with stage 3 colon cancer in 2021, exemplified the program's success. Working with a physiotherapist to establish and maintain a personalized fitness routine, she emphasized the importance of structured support. "One of the biggest benefits was having a semi-structured routine that works for my lifestyle with someone to hold me accountable," she said. "Simply being told to exercise by a physician wouldn't have been enough to get me to where I am today."
Three years later, Swain-Collins continues her exercise routine, walking three times weekly, and remains cancer-free while maintaining improved fitness levels.
Healthcare System Integration
The researchers are conducting a comprehensive health economic analysis and anticipate the program will be "remarkably cost-effective compared to many new cancer drugs," making it sustainable for health systems. Dr. Booth advocates for a new care model where colon cancer patients who complete surgery and chemotherapy are referred to exercise specialists for structured three-year interventions.
Disease Context
Colorectal cancer represents the second leading cause of cancer death in Canada, with an estimated 25,200 Canadians diagnosed and 9,400 deaths in the previous year. The trial's findings have potential implications for tens of thousands of people affected by colorectal cancer annually.
The international collaboration included researchers from the Canadian Cancer Trials Group, with international co-chairs Dr. Janette Vardy from The University of Sydney and Dr. Victoria Coyle from Queen's University of Belfast, supported by funding from the Canadian Cancer Society, National Health and Medical Research Council, and Cancer Research UK.
