Cost-effectiveness of blood-based colorectal cancer screening: A simulation model incorporating real-world longitudinal adherence.

93 Background: Colorectal cancer (CRC) is a predominant cause of cancer-related mortality worldwide. Regular screening improves outcomes. However, despite there being many U.S. Preventive Services Task Force (USPSTF) recommended CRC screening options, many people elect not to use any of them. Most cost-effectiveness models assume perfect (100%) adherence initially and over time (longitudinally), which is implausible as approximately one-third of eligible individuals are not up to date with CRC screening. Our study evaluates the cost-effectiveness of Shield, an FDA-approved blood-based CRC test, while incorporating real-world adherence. Methods: The CAN-SCREEN (Colorectal cANcer SCReening Economics and adherENce) model is a validated, discrete-event simulation model designed to evaluate the clinical and economic outcomes of CRC screening strategies under real-world adherence scenarios. We simulated individual lifetime outcomes for a cohort of 10,000 people beginning screening at age 45, running 4,000 trials per cohort. We conducted a cost-effectiveness analysis using the CAN-SCREEN model, and compared the Shield blood-based test administered every three years to no screening. Costs were calculated from a healthcare perspective and adjusted to 2023 US dollars. Shield was considered cost-effective if the incremental cost-effectiveness ratio (ICER) was below $100,000 per quality-adjusted life-year (QALY) gained. The analysis also assessed the maximum price Shield could maintain while remaining cost-effective. Results: Compared to no screening, Shield increased the number of QALYs by 154 per 1,000 individuals and raised costs by $7.5 million per 1,000 individuals at its commercial test cost. With an incremental cost of $48,662 per QALY gained, Shield was found to be cost-effective relative to no screening at $100,000 cost per QALY willingness-to-pay threshold. Furthermore, the unit cost of Shield can be as high as $3,241 and $4,942 to be considered cost-effective at $100,000 and $150,000 per QALY gained, respectively. Conclusions: This study used the CAN-SCREEN model to compare Shield, an FDA-approved blood-based CRC screening test, against no screening, finding that Shield is cost-effective. With about one-third of the U.S. population not up to date on CRC screening, Shield's noninvasive approach offers a promising, cost-effective solution to increase adherence and reduce CRC mortality. Economic outcomes of Shield against no screening using CAN-SCREEN model. Intervention Test Unit Cost QALYs/Person Cost ($)/Person Cost ($)/QALY Gained vs No screening No Intervention - 15.269 $6,312.18 - Shield $1,495 15.423 $13,786.72 $48,662 Shield $3,241 15.423 $21,672.34 $100,000.00 Shield $4,942 15.423 $29,352.42 $150,000.00