Cost-Effectiveness of Noninvasive Colorectal Cancer Screening in Community Clinics

Several noninvasive tests for colorectal cancer screening are available, but their effectiveness in settings with low adherence to screening and follow-up colonoscopy is not well documented.

To assess the cost-effectiveness of and outcomes associated with noninvasive colorectal cancer screening strategies, including new blood-based tests, in a population with low adherence to screening and ongoing surveillance colonoscopy.

The validated microsimulation model used for the decision analytical modeling study projected screening outcomes from 2025 to 2124 for a simulated cohort of 10 million individuals aged 50 years in 2025 and representative of a predominantly Hispanic or Latino patient population served by a Federally Qualified Health Center in Southern California. The simulated population had low adherence to first-step noninvasive testing (45%), second-step follow-up colonoscopy after an abnormal noninvasive test result (40%), and ongoing surveillance colonoscopy among patients with high-risk findings at follow-up colonoscopy (80%).

Colorectal cancer screening strategies included no screening, an annual or biennial fecal immunochemical test, a triennial multitarget stool DNA test, and a triennial blood-based test. Using a blood-based test was assumed to increase first-step adherence by 17.5 percentage points.

Outcomes included colorectal cancer incidence and mortality, life-years gained and quality-adjusted life-years gained relative to no screening, costs, and net monetary benefit assuming a willingness to pay of $100 000 per quality-adjusted life-year gained.

Under realistic adherence assumptions, a program of annual fecal immunochemical testing was the most effective and cost-effective strategy, yielding 121 life-years gained per 1000 screened individuals and a net monetary benefit of $5883 per person. Triennial blood testing was the least effective, yielding 23 life-years gained per 1000, and was not cost-effective, with a negative net monetary benefit. Annual fecal immunochemical testing with 45% first-step adherence and 80% adherence to follow-up and surveillance colonoscopy yielded greater benefit than triennial blood testing with perfect adherence (88 vs 77 life-years gained per 1000).

This study suggests that in a federally qualified health care setting, prioritizing the convenience of blood tests over less costly and more effective existing stool-based tests could result in higher costs and worse population-level outcomes. Novel screening modalities should be carefully evaluated for performance in community settings before widespread adoption.