COST-EFFECTIVENESS ANALYSIS FOR VARIOUS COLORECTAL CANCER SCREENING STRATEGIES IN TAIWAN

Purpose: To evaluate colorectal cancer (CRC) screening strategies for the Taiwanese population compared with the current policy of biennial fecal occult blood testing (FOBT) for ages 50-69 without post-polypectomy surveillance.

Method: We developed a Monte Carlo microsimulation model to track the incidence, size and location of adenomas and their potential progression to CRC, for a hypothetical cohort of 50-year-old Taiwanese at average risk for CRC. We evaluated screening strategies that extend the age range for screening (50-69 to 50-75), decrease the screening interval (biennial to annual), add post-polypectomy surveillance, and evaluate different screening modalities (colonoscopy, sigmoidoscopy) at recommended intervals. We assumed 60% adherence with FOBT and 40% adherence with endoscopy. The cost-effectiveness analysis was conducted from a third-party payer perspective. Sensitivity analyses were performed to test the robustness of the finding when varying adherence and test performance.

Result: The current Taiwanese policy reduced CRC incidence by 23% and CRC mortality by 28%. Adding post-polypectomy surveillance to the current policy further reduced both incidence and mortality by an absolute 2%, while extending the age range along with the surveillance contributed to additional 6% increase in the effect compared with the current policy. Annual FOBT from age 50 to 75 along with surveillance reduced CRC incidence by 46% and CRC mortality by 52%, and was consistently cost saving compared to the current policy in both base-case and sensitivity analyses. Ten-yearly colonoscopy was more effective than the current policy, but it was also more costly in the base-case analysis and under the optimal adherence scenario, whereas it was cost saving when we used lower test performance estimates for FOBT. Extending the age range with surveillance was consistently more effective and less costly than adding surveillance alone relative to the current policy in sensitivity analyses. 

Conclusion: The costs associated with expanding the current Taiwanese CRC screening program to include annual FOBT with surveillance for individuals aged 50-75 would be offset by the cancer treatment costs averted, and would reduce the burden of CRC in Taiwan.