June 1, 2025

expert reaction to randomised trial on physical exercise and reduced risk of recurrence of colon cancer

A randomised trial published in The New England Journal of Medicine and a conference abstract presented at the American Society of Clinical Oncology meeting 2025 (ASCO) looks at physical exercise and colon cancer recurrence. 

Professor David Sebag-Montefiore, Audrey and Stanley Burton Professor of Clinical Oncology and Health Research, University of Leeds, said:

“The results of the CHALLENGE trial provide high quality evidence that a structured moderate intensity exercise programme after surgery and chemotherapy reduces the chances of bowel cancer returning.

“This is excellent news for future patients with bowel cancer and is likely to bring additional health benefits.

“Having worked in bowel cancer research for 30 years, this is an exciting breakthrough in the step-wise improvement in cure rates that has been achieved through cutting edge research in surgery, pathology, radiotherapy and chemotherapy.

“The great appeal of a structured moderate intensity exercise is that is offers the benefits without the downside of the well-known side effects of our other treatments.”

Dr Marco Gerlinger, Professor of Gastrointestinal Cancer Medicine and Consultant Medical Oncologist, Barts Cancer Institute, Queen Mary University of London, said:

“This is a really important study. It’s the first randomised trial showing that physical exercise can reduce the risk of recurrences, new cancer diagnoses and death in patients who had surgery followed by chemotherapy for an early-stage colon cancer. Major confounders such as baseline physical activity, tumour stage, comorbidities or age did not differ between the groups in this randomised trial. I could not find information on the exact N stage of patients in the two groups which is a slight limitation. The paper shows that the same proportion of patients in the two groups had stage 3 disease which tumours where local lymph nodes were involved. But it does not show if the proportion of patients with N1 (up to 3 nodes positive), N2a (4-6) and N2b (7 and more) was similar. The recurrence risk of N2 is quite a bit higher than N1, and imbalance may hence lead to a difference. Maybe this data is somewhere in the supplements but that was not available to me. All patients had chemotherapy after their surgery and an exercise program that added activities such as jogging for 30 minutes three times a week or brisk walking for an hour three times per week led to a 30% further reduction in the risk of cancer recurrence and death. This indicates that exercise has a similarly strong effect as previously shown for chemotherapy, which is really quite impressive. One of the commonest questions from patients is what they can do to reduce the risk that their cancer comes back. Oncologists can now make a very clear evidence based recommendation for patients who just completed their chemotherapy for bowel cancer and are fit enough for such an exercise program. I think that support from their doctor and a physiotherapist or trainer will almost certainly be necessary to make this effective for the majority of patients.”

Professor Amy Berrington, Team Leader in Clinical Cancer Epidemiology at The Institute of Cancer Research, London, said:

“There have been several observational studies that suggested that exercise after colorectal diagnosis could reduce the risk of colorectal cancer mortality by about 25 per cent for 10 MET/hours per week.

“The findings from this large well-conducted trial are quite consistent with those previous observational studies – the trial found a 28 per cent reduction in disease-free survival with an exercise programme designed to increase exercise by 10 MET/hours per week.

“The two treatment groups were well balanced with respect to potential confounders through the randomisation. The programme was quite intensive, and adherence decreased over the three years, but the amount of exercise remained higher in the structured exercise programme group.

“It would be important to know how expensive these types of behaviour support programs are to evaluate the cost-effectiveness.  Also, the recruitment was very slow, suggesting that it was difficult to find patients willing to commit to this long programme, but hopefully these very positive results will help convince more patients to try what looks like a very promising safe and effective ‘treatment’.”      

The abstract ‘A randomized phase III trial of the impact of a structured exercise program on disease–free survival (DFS) in stage 3 or high-risk stage 2 colon cancer: Canadian Cancer Trials Group (CCTG) CO.21 (CHALLENGE)’ was presented at the American Society of Clinical Oncology meeting 2025, and the paper ‘Structured Exercise after Adjuvant Chemotherapy for Colon Cancer’ by Kerry S. Courneya et al. was published in The New England Journal of Medicine at 13:00 UK time Sunday 1 June 2025. 

DOI: 10.1056/NEJMoa2502760

Declared interests

No reply to our request for DOIs was received.