Comparative benefits, burdens, and harms of emerging blood-based tests for colorectal cancer screening

Emerging blood tests may improve colorectal cancer (CRC) screening uptake and outcomes but are less sensitive for advanced precancerous lesions than some currently recommended tests. We examine whether these tests meet expectations for the US Preventive Services Task Force (USPSTF) recommendation.

A decision-analytic model that informed USPSTF was replicated and used to estimate the lifetime benefits (averted CRC cases and deaths, life-years gained [LYG]), burdens (required screening tests and colonoscopies), and harms (colonoscopy-related complications) for annual, biennial, or triennial blood testing through age 45-75 years vs a benchmark of recommended and contemporary stool-based strategies, with colonoscopy screening as the reference. Base-case analyses assumed 100% adherence. Sensitivity analyses evaluated more realistic scenarios.

Among benchmark strategies, colonoscopy screening had the most benefit, with an estimated 30 CRC deaths averted, 356 LYG, 4270 colonoscopies required, and 15 complications per 1000 adults; stool-based strategies resulted in 81% to 88% of LYG for colonoscopy, 6829-19 476 screening tests, 1523-1880 colonoscopies, and 9-10 complications. By comparison, annual blood testing resulted in 85% to 87% of LYG for colonoscopy and an intermediate number of screenings, colonoscopies, and complications. Biennial and triennial blood testing provided 57% to 72% of LYG for colonoscopy but resulted in net population benefit under plausible scenarios for increased utilization vs existing strategies.

The estimated benefits, burdens, and harms of annual blood testing are within the range of current CRC screening strategies. Biennial and triennial testing should also be considered for recommendation given the potential for increased utilization and net population benefit.