Participation and Yield in Multiple Rounds of Colorectal Cancer Screening based on Fecal Immunochemical Test: A Systematic Review and Meta-Analysis

Background and aims: The evidence on the cumulative participation and yield in multiple rounds of colorectal cancer (CRC) screening based on fecal immunochemical test is sparse. We aimed to assess the trends in participation and detection for advanced colorectal neoplasm under different screening intervals in multi-round FIT-based CRC screening by synthesizing the current available evidence. Methods: PubMed, Embase, and Cochrane were retrieved from January 1, 2002 to April 16, 2024 for potential eligible studies and then we synthesized participation and advanced colorectal neoplasm detection rates for each screening round, along with their respective 95% confidence intervals. Results: 19 studies involving a total of 2,296,071 individuals were included. As screening rounds increased, participation exhibited a gradual consistent increase, reaching 78.45% and 74.97% for annual and biennial screening strategies. For annual screening, the cumulative detection rates for 3 rounds were 1.38% (95% CI: 1.18–1.63%), 1.95% (95% CI: 1.72–2.21%), and 2.50% (95% CI: 2.29–2.72%), respectively. For biennial screening, the cumulative detection rates for 4 rounds were 2.22% (95% CI: 1.22–3.22%), 3.44% (95% CI: 2.06–4.82%), 4.26% (95% CI: 2.70–5.83%), and 5.10% (95% CI: 3.28–7.29%), respectively. Notably, the per-round detection rate of advanced colorectal neoplasms declined yet as the screening progressed. Conclusion: In population-based CRC screening programs, the participation exhibited a slow upward trend for both screening strategies, but the incremental benefits in CRC detection gradually diminished. Tailored strategies, such as extending intervals for individuals with multiple negative FIT results, might optimize effectiveness and cost-efficiency in population-based CRC screening.