Cost-effectiveness analysis of aspirin and structured exercise as adjuvant therapy in localized colorectal cancer.

3650 Background: The ALASCCA trial demonstrated that 160 mg of aspirin daily for 3 years reduced the risk of localized colorectal cancer recurrence in patients with PIK3CA exons 9/20 (group A) or PIK3R1/PTEN/other PIK3CA alterations (group B). The CHALLENGE trial demonstrated that increasing recreational aerobic activity above baseline through a 3-year structured exercise program reduces the risk of colon cancer recurrence. These interventions have not been adopted into Canadian clinical practice (CCP), and we evaluated the cost-effectiveness of strategies to implement them as adjuvant therapy for localized, operable colorectal cancer from the Canadian public healthcare perspective. Methods: We developed a decision model to project clinical and economic consequences of six strategies: (1) “CCP,” defined as no exercise or aspirin interventions; (2) “Aspirin for group A PI3K alterations,” defined as testing for group A PI3K alterations and treating positive patients with aspirin; (3) “Aspirin for group A/B PI3K alterations,” defined as testing for group A/B PI3K alterations and treating positive patients with aspirin; (4) “Aspirin for all,” defined as treating all patients with aspirin regardless of PI3K status; (5) “Structured exercise alone,” defined as initiating all patients on a structured exercise program with no aspirin intervention; and (6) “Aspirin for group A/B PI3K alterations and structured exercise,” defined as testing for group A/B PI3K alterations, treating positive patients with aspirin, and initiating all patients on a structured exercise program. The model was parameterized using survival data from the ALASCCA and CHALLENGE trials, and cost and utility data from Alberta, Canada, and Canadian sources. Costs are presented in 2025 Canadian dollars. Future costs and benefits were discounted at 1.5%. Results: Compared with the CCP, all interventional strategies were associated with greater QALY gains and lower per-person costs, resulting in overall cost savings (Table). The “aspirin for group A/B PI3K alterations and structured exercise” strategy emerged as the dominant intervention, yielding the highest QALYs gained and greatest cost savings per person. Implementing this strategy into CCP would avert disease recurrence in 940 patients per year, generate 2,625 total QALYs annually, and produce total budget savings of $399 million per year. Conclusions: The integration of PI3K group A/B–guided aspirin therapy with structured exercise as adjuvant treatment for localized colorectal cancer should be adopted into CCP, given its considerable societal benefit. Strategy Inc. QALY gained/pers. Cost saving/pers. CP Ref Ref Aspirin for group A PI3K alterations 0.05 9,400 Aspirin for group A/B PI3K alterations 0.12 20,200 Aspirin for all 0.07 14,700 Structured exercise alone 0.13 23,700 Aspirin for group A/B PI3K alterations and structured exercise 0.22 33,700