Cost-effectiveness of targeted vs. multi-cancer blood tests for colorectal cancer.

Abstract

e15526 Background: Recent research suggested that current blood tests are not cost-effective for colorectal cancer (CRC) screening in patients declining other options, i.e., compared to not screening those patients.(1) The findings were from a new decision-analytic model evaluating a multi-cancer detection (MCD) test. Relative to this MCD test, emerging “targeted” CRC blood tests have higher suggested sensitivity for CRC precursors and lower specificity for subjects without any adenomas or CRC. We examine the cost-effectiveness of these emerging tests. Methods: An established CISNET model was replicated, validated, and then used to evaluate blood testing from age 45 to age 75 years, at 1, 2 or 3-year intervals. An MCD test (Galleri®) with 99.5% specificity, 0.5% advanced adenoma (AA) sensitivity, and 82.0% CRC sensitivity (99.5%, 0.5%, 82%) was compared to two hypothetical targeted CRC tests: a low-sensitivity blood test (lsBT) just meeting U.S. national coverage criteria (90%, 10%, 74%), and a high-sensitivity blood test (hsBT) with performance assumptions based on published data (90%, 20%, 90%). Galleri costs $949 per test; lsBT and hsBT costs were varied ($100-$1500). Outcomes included the estimated mortality reduction, and the discounted quality-adjusted life-years (QALY) gained, costs of screening, follow-up colonoscopy and treatment, and costs/QALY gained vs. no screening. Results: Estimated lifetime CRC incidence and mortality without screening were 85.9 and 32.9 per 1000, respectively. Triennial screening with Galleri reduced estimated CRC mortality by 15.6%, yielded 26.9 QALYs gained per 1000, and cost $191,135/QALY gained. Annual screening increased benefit to 28.9% mortality reduction and 46.6 QALYs gained, at $300,254/QALY gained. In contrast, at $1000 per test, lsBT every 1-3 years reduced mortality by 50.2-76.4%, yielded 71.0-109.5 QALYs gained, and cost $51,330-$67,420/QALY gained. hsBT testing further improved outcomes to 60.8-80.9% mortality reduction, 88.1-119.6 QALY gained, and $35,519-$58,125/QALY gained. Costs per QALY gained were lower for lsBT and hsBT vs. Galleri irrespective of the assumed unit costs, and never exceeded $82,902 for triennial testing. Conclusions: Emerging targeted blood tests for CRC can be cost-effective for screening and could be important in reaching underserved populations, once available. Targeted tests and MCD tests differ meaningfully in their accuracy, clinical interpretation, and use, and should not be treated as a similar type of screening test.