Structured exercise program following adjuvant chemotherapy for colon cancer: A cost-utility analysis of the CHALLENGE trial

PURPOSE: The phase III CHALLENGE trial (CCTG CO.21) demonstrated that a 3-year structured exercise program (SEP) improved disease-free and overall survival versus health education materials (HEM) in patients with stage III or high-risk stage II colon cancer after surgery and adjuvant chemotherapy. We assessed the cost-effectiveness of the SEP versus HEM. METHODS: This pre-specified economic evaluation used prospectively collected data from all trial participants (n = 889). The base case adopted the Canadian public payer perspective and included direct healthcare costs over a 5-year time horizon with a 1.5% discount rate. 36-Item Short Form (SF-36) outcomes were mapped to Short-Form 6-Dimension (SF-6D) utilities using a validated algorithm. Mean costs (2024 CAD) and effects (life-years (LYs) and quality-adjusted life-years (QALYs)) per participant in each intervention group were used to estimate the incremental costs, incremental LYs/QALYs, incremental cost-effectiveness ratio (ICER, $/life-year gain (LYG)), and incremental cost-utility ratio (ICUR, $/QALY) when applicable. Uncertainty was assessed via bootstrapping (1,000 samples). Notable scenario analyses included a 10-year time horizon and a societal perspective incorporating lost wages due to missed work, measured through the Work Productivity and Activity Impairment questionnaire. RESULTS: In the base case, despite an up-front cost of $2,917 to provide the exercise sessions, the SEP ($31,957) was dominant over HEM ($33,546), being less costly (-$1,589) and more effective (+0.05 LYs; +0.10 QALYs). The SEP was dominant in 53% of bootstrap samples, and 80% fell below a $50,000 per QALY willingness-to-pay threshold. Major cost drivers were cancer recurrence or new malignancy and anticancer therapy. Scenario analyses were consistent with the base case. CONCLUSION: The SEP was less costly and more effective than HEM. This study can inform payers and health-systems with implementation of SEPs in routine care.