CHALLENGE (CCTG CO.21)
The first randomised trial to show that a coached exercise programme after cancer treatment reduces recurrence and death, in colon cancer.
889 patients across Canada, Australia, UK, Israel and the US were randomised within 2-6 months of completing adjuvant chemotherapy to a structured exercise programme delivered by physical activity consultants (behavioural support sessions and supervised exercise, tapering over three years, targeting an increase of 10 MET-hours/week) or to health-education materials. Median follow-up 7.9 years. Disease-free survival at 5 years 80.3% vs 73.9% (HR 0.72, 95% CI 0.55-0.94); overall survival at 8 years 90.3% vs 83.2% (HR 0.63, 95% CI 0.43-0.94). Physical functioning and VO2 improved in the exercise arm; musculoskeletal adverse events were more common (18.5% vs 11.5%). The effect size is comparable with adding oxaliplatin to fluoropyrimidine adjuvant therapy. Limitations: one disease, open-label, participants were relatively fit volunteers, and the intervention required a trained workforce.
- 80.3 vs 73.9 out of 100 alive without the cancer coming back at 5 years with Structured exercise compared with Health education; 6.4 more per 100.
- Roughly one extra person helped for every 16 treated. That is a rough figure taken from the two percentages, not a guarantee for any one person.
- Put another way, the treated group had about 28 percent lower chance of the event at any given time (hazard ratio 0.72, likely range 0.55 to 0.94).
- This is a surrogate endpoint: it measures the cancer being controlled or absent on scans and tests, which often, but not always, translates into living longer.
- 90.3 vs 83.2 out of 100 alive at 8 years with Structured exercise compared with Health education; 7.1 more per 100.
- Roughly one extra person helped for every 14 treated. That is a rough figure taken from the two percentages, not a guarantee for any one person.
- Put another way, the treated group had about 37 percent lower chance of the event at any given time (hazard ratio 0.63, likely range 0.43 to 0.94).
- Overall survival counts deaths from any cause, so it is the most direct measure of whether a treatment helps people live longer.
- These results apply to the people the trial enrolled: Resected stage III or high-risk stage II colon cancer after adjuvant chemotherapy: 3-year structured exercise programme vs health-education materials. People in a different situation may not see the same effect.
Numbers are from the trial as recorded here; see the source links in the table below. This is orientation, not medical advice: ask your team how closely the trial population matches you.
889 participants enrolled.
| Endpoint | Arm | n | Value | HR (95% CI) | p | Source |
|---|---|---|---|---|---|---|
| Disease-free survival at 5 yearsprimary | Structured exercise | 445 | 80.3% | 0.72 (0.55–0.94) | 0.02 | link |
| Health education | 444 | 73.9% | ||||
| Overall survival at 8 years | Structured exercise | — | 90.3% | 0.63 (0.43–0.94) | — | link |
| Health education | — | 83.2% |