A Cost-Effectiveness Analysis of Early Colorectal Cancer Screening Using Multi-target Stool DNA and Optical Colonoscopy in African Americans

Abstract

Introduction: Despite population-level improvements in colorectal cancer (CRC) mortality, disturbing disparities persist. African-Americans (AA) have lower utilization of existing screening modalities compared to other racial groups. As such, we sought to explore the cost-effectiveness of early CRC screening using a less invasive screening test, multi-target stool DNA (MTS-DNA), compared to optical colonoscopy (OC). Methods: We performed an economic evaluation of various colorectal cancer screening strategies using an agent-based population microsimulation model that was contextualized to AA and validated with independent data. Screening strategies included 1) OC every 10 years from age 50 (as recommended by the United States Preventive Services Task Force); 2) OC every 10 years from age 45 as recommended by the American College of Gastroenterology; strategies 3 to 5 involved screening with MTS-DNA alone every 3 years, with a follow-up OC if indicated, from ages 40, 45, and 50 years, respectively, accounting for 5 strategies in all. Primary outcomes of interest were quality-adjusted life-years (QALYs) gained after turning 40, average costs per patient and incremental cost effectiveness ratios (ICERs). Results: In the base-case analysis, preliminary results suggest that the most cost-effective strategy is OC from age 50. This strategy has an ICER of over $8,000/QALY gained, comparable to ICERs estimated for the same screening strategy in similar studies. MTS-DNA from age 50 was the next best strategy. Other strategies were dominated by OC from age 50 (i.e. cost more and yielded fewer benefits). Preliminary results from probabilistic sensitivity analyses suggest that initiating CRC screening using OC from age 50 is the preferred strategy in at least 60% of iterations at a $50,000 willingness-to-pay threshold. Two-way sensitivity analyses suggest that the model may be sensitive to assumptions of MTS-DNA costs, and also to utilization rates for MTS-DNA and OC in this high-risk population. Conclusion: Our preliminary results suggest that earlier CRC screening in AA before age 50 may not be cost-effective. Increasing the uptake of existing screening modalities may have more benefits from a population perspective, in reducing the burden of colorectal cancer.