Cost-effectiveness of surveillance after curative resection (CR) of metastatic colorectal cancer (CRC).

526Background: Surveillance after CR of stage I-III CRC is recommended by most major oncology organizations to detect asymptomatic recurrences. Such recurrences are more likely to benefit from early interventions such as CR of metastases. Only the NCCN recommends a surveillance schedule after CR of metastases that includes CEA testing, imaging and clinical evaluation every 3-6 months for 2 years, and then every 6-12 months in years 3 to 5. Periodic endoscopy is also recommended. It is unclear if there is cost-effective surveillance strategy for metastatic CRC after CR. Methods: A Monte Carlo micro-simulation model was constructed using a 1-month cycle length and 10 year time horizon. Surveillance strategies were compared based on NCCN guidelines, with testing every 3 months (3M) or 6 months (6M), as well as two alternate strategies of testing every 12 months (12M) or no surveillance (None) for 5 years. Recurrence, repeat CR rates, and survival outcomes were modeled from population-based outcomes of 257 pa...