The CHALLENGE study was an international, phase III randomised controlled trial evaluating a 3-year structured exercise program (SEP) compared to health education materials (HEM) in survivors of early-stage colon cancer who had completed adjuvant chemotherapy 2-6 months previously. The primary endpoint was disease-free survival (DFS).
The study ran from 2009 to 2024, with 889 patients randomised from 55 centres. SEP participants had significantly greater DFS than the HEM group (HR 0.72; 95%CI 0.55 to 0.094; p=0.02) at a median follow up of 8 years. Overall survival was 90% vs 83%, equating to a 37% risk reduction. Physical activity, fitness, quality of life physical functioning subscale were all significantly better in the exercise group. Musculoskeletal adverse events were higher in the exercise group (18.5% vs 11.5%).
While the study was successful and defines exercise as an adjuvant therapy within standard of care for colon cancer survivors, it was not without difficulties in its 17 year lifespan. Discussion will cover the challenges of running a multi-centre international trial, including funding, recruitment issues, and unique
challenges with lifestyle interventions. Difficulties in applying the results of a lifestyle study, despite the strong survival benefit, will also be discussed.