A groundbreaking international study reveals that regular exercise after colon cancer treatment reduces recurrence risk by 28%, potentially rivaling or exceeding the benefits of some pharmaceutical interventions.

At a Glance

• The first randomized controlled trial of its kind found structured exercise programs significantly reduced cancer recurrence and improved survival in colon cancer patients
• Participants who exercised had 28% fewer cancers and 37% fewer deaths from any cause after eight years of follow-up
• The exercise program was equivalent to brisk walking for 45 minutes, four days per week
• Researchers now advocate for exercise to be considered a standard treatment for colon cancer patients, not just for quality of life
• The study followed nearly 900 patients across six countries for approximately eight years

A Natural Approach to Cancer Prevention

A landmark Phase 3 randomized controlled trial published in the New England Journal of Medicine has demonstrated that exercise can significantly reduce the risk of cancer recurrence in patients who have completed treatment for Stage 3 or high-risk Stage 2 colon cancer. The study, presented at the American Society of Clinical Oncology (ASCO) annual meeting, followed nearly 900 patients from Canada, Australia, the UK, Israel, and the US for approximately eight years between 2009 and 2024. With an average participant age of 61, about 90% had Stage 3 colon cancer, which typically has a concerning 35% recurrence rate within five years after treatment.

"When we saw the results, we were just astounded," said study co-author Dr. Christopher Booth, a cancer doctor at Kingston Health Sciences Centre in Kingston, Ontario. "What it translated to for most people is going on a brisk walk 45 minutes a day, four days per week."

Impressive Results Challenge Standard Care

The study's design was straightforward yet powerful. Half of the participants were enrolled in a structured exercise program that gradually increased their physical activity over six months, with coaching support available for up to three years. The exercise program aimed for a weekly increase of 10 MET hours, equivalent to about four hours of brisk walking. The control group received only an educational booklet on exercise and diet. The results were remarkable: participants in the exercise group showed a 28% reduction in cancer recurrence, new cancer diagnosis, or death compared to the control group.

The exercise group's survival rates were impressive, with 90% not experiencing cancer recurrence or new diagnoses, compared to 83% in the control group. Additionally, those in the exercise program had 37% fewer deaths from any cause after eight years. This exercise-based approach even showed protective effects against other types of cancer, including breast and colorectal cancers.

From Research to Clinical Practice

The CHALLENGE (CO21) trial, as it was known, marks a significant shift in how cancer treatment could evolve. Funded by academic research groups in Canada, Australia, and the UK, the study provides oncologists with evidence-based recommendations for improving patient outcomes post-treatment. Researchers are now investigating exactly how exercise may prevent cancer, with theories focusing on improved insulin processing or immune system enhancement. The cost of implementing such exercise programs is estimated at several thousand dollars per patient, making it a relatively affordable intervention compared to many pharmaceutical options.

The results are particularly meaningful for patients seeking ways to take control of their health after cancer treatment. However, researchers acknowledge the challenge of integrating exercise into patients' lives, especially without access to coaching support. "It's not as simple as telling people to exercise. We know that for many people, getting an exercise habit is very difficult. We really need [insurers] to cover this," noted Dr. Booth. The study calls for policy changes to include exercise in clinical practice guidelines for cancer care.

A New Standard of Cancer Care

While exercise is viewed as an additional therapy rather than a replacement for standard cancer care, these findings represent a potential paradigm shift in post-treatment protocols. The study builds on previous observational research linking regular exercise to longer survival in colon cancer patients, but provides the highest quality evidence to date. For the millions of cancer survivors worldwide, this research offers both hope and practical guidance for reducing recurrence risk through natural means within their control.