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

3507 Background: The phase III CHALLENGE trial (CCTG CO.21) demonstrated improved disease-free and overall survival with a 3-year structured exercise program (SEP) compared with health education materials (HEM) in participants with stage III or high-risk stage II colon cancer that had undergone surgery and adjuvant chemotherapy. This study evaluated the cost-effectiveness of SEP versus HEM. Methods: A pre-specified economic evaluation was conducted using prospectively collected data from all trial participants (n = 889). The base case adopted the Canadian public healthcare payer perspective and included direct healthcare costs (cost categories available in Table 1), a 5-year time horizon, and a 1.5% discount rate. SF-36 trial data were mapped to SF-6D using a validated algorithm to calculate health utilities. Costs (2024 CAD) and effects measured as life-years (LYs) and quality-adjusted life-years (QALYs) were used to estimate an incremental cost-effectiveness ratio (ICER, $/life year gain (LYG)) and incremental cost-utility ratio (ICUR, $/QALY). Uncertainty was assessed via bootstrapping (n = 1,000). Notable scenario analyses included a 10-year horizon and a societal perspective capturing indirect costs from wages lost due to missed work, measured using a Work Productivity and Activity Impairment questionnaire. Results: In the base case, despite the up-front $4327 cost of the SEP intervention, the SEP was dominant over HEM (i.e less costly (−$179) and more effective (+0.06 LYs; +0.10 QALYs)). The SEP was dominant in 49% of bootstrap samples, while 79% met a $50,000 per QALY willingness-to-pay threshold. Major cost drivers in both groups were the costs of recurrence or new malignancy and anticancer therapy. Scenario analysis results were consistent with the base case analysis. The SEP remained dominant with a 10-year time horizon yielding greater cost savings ($-2,528) and more LYG (0.35) than the base case. From a societal perspective, the ICUR was $3,571/QALY, a highly cost-effective strategy. Conclusions: The SEP was less costly and more effective when compared with HEM. These data can inform health systems and payers as they look to implement SEP in routine models of care. Mean per participant costs, effects, and ICER/ ICUR for the base case analysis. SEP(n=445) HEM(n=444) Increment Cost of SEP sessions (including fixed start-up costs) ($) 4,327 0 4,327 Cost of hospitalization (pre- or without recurrence) ($) 3,593 3,092 501 Cost of recurrence or new malignancy (physicians, lab tests, drugs, hospitalizations, surgery, emergency room visits, home care)($) 12,732 15,772 -3,040 Cost of anticancer therapy ($) 12,660 14,582 -1,922 Cost of end-of-life care ($) 54 100 -46 Total cost ($) 33,367 33,546 -179 Total LYs 4.72 4.66 0.06 Total QALYs 3.84 3.75 0.09 ICER ($/LYG) and ICUR ($/QALY) Dominant* *SEP is less costly and more effective than HEM.