AIM:To identify a cost-effective strategy of second primary colorectal cancer (CRC) screening for cancer survivors in Korea using a decision-analytic model.METHODS: A Markov model estimated the clinical and economic consequences of a simulated 50-year-old male cancer survivors’ cohort, and we compared the results of eight screening strategies: no screening, fecal occult blood test (FOBT) annually, FOBT every 2 years, sigmoidoscopy every 5 years, double contrast barium enema every 5 years, and colonoscopy every 10 years (COL10), every 5 years (COL5), and every 3 years (COL3). We included only direct medical costs, and our main outcome measures were discounted lifetime costs, life expectancy, and incremental cost-effectiveness ratio (ICER).RESULTS: In the base-case analysis, the non-dominated strategies in cancer survivors were COL5, and COL3. The ICER for COL3 in cancer survivors was $5593/life-year saved (LYS), and did not exceed $10000/LYS in one-way sensitivity analyses. If the risk of CRC in can- cer survivors is at least two times higher than that in the general population, COL5 had an ICER of less than $10500/LYS among both good and poor prognosis of index cancer. If the age of cancer survivors starting CRC screening was decreased to 40 years, the ICER of COL5 was less than $7400/LYS regardless of screening compliance.CONCLUSION: Our study suggests that more strict and frequent recommendations for colonoscopy such as COL5 and COL3 could be considered as economically reasonable second primary CRC screening strategies for Korean male cancer survivors. AIM: To identify a cost-effective strategy of second primary colorectal cancer (CRC) screening for cancer survivors in Korea using a decision-analytic model. METHODS: A Markov model estimated the clinical and economic consequences of a simulated 50-year-old male cancer survivors’ cohort, and we compared the results of eight screening strategies: no screening, fecal occult blood test (FOBT) annually, FOBT every 2 years, sigmoidoscopy every 5 years, double contrast barium enema every 5 years, and colonoscopy every 10 years (COL10), every 5 years (COL5), and every 3 years (COL3). We included only direct medical costs, and our main outcomes measures were discounted lifetime costs, life expectancy, and incremental cost-effectiveness ratios (ICER) .RESULTS The ICER for COL3 in cancer survivors was $ 5593 / life-year saved (LYS), and did not exceed $ 10000 / LYS in one- way sensitivity analyses. If the risk of CRC in can-cer survivors is at least two times higher than that in the general population, COL5 had an ICER of less than $ 10500 / LYS among both good and poor prognosis of index cancer. If the age of cancer survivors starting CRC screening was decreased to 40 years, the ICER of COL5 was less than $ 7400 / LYS regardless of screening compliance. CONCLUSION: Our study suggests that more strict and frequent recommendations for colonoscopy such as COL5 and COL3 could be considered as economically reasonable second primary CRC screening strategies for Korean male cancer survivors.