Stratification of Stage II Colon Cancer Using Recurrence Prediction Value: A Multi-institutional International Retrospective Study.

OBJECTIVE: To create a recurrence prediction value (RPV) of high-risk factor and identify the patients with high risk of cancer recurrence. SUMMARY BACKGROUND DATA: There are several high-risk factors known to lead to poor outcomes. Weighting each high-risk factor based on their association with increased risk of cancer recurrence can provide a more precise understanding of risk of recurrence. METHODS: We performed a multi-institutional international retrospective analysis of patients with Stage II colon cancer patients who underwent surgery from 2010 to 2020. Patient data from a multi-institutional database were used as the Training data, and data from a completely separate international database from two countries were used as the Validation data. The primary endpoint was recurrence-free survival (RFS). RESULTS: A total of 739 patients were included from Training data. To validate the feasibility of RPV, 467 patients were included from Validation data. Training data patients were divided into RPV low (n = 564) and RPV high (n = 175). Multivariate analysis revealed that risk of recurrence was significantly higher in the RPV high than the RPV low (Hazard ratio (HR) 2.628; 95% confidence interval (CI) 1.887-3.660; P < 0.001). Validation data patients were divided into two groups (RPV low, n = 420) and RPV high (n = 47). Multivariate analysis revealed that risk of recurrence was significantly higher in the RPV high than the RPV low (HR 3.053; 95% CI 1.962-4.750; P < 0.001). CONCLUSIONS: RPV can identify Stage II colon cancer patients with high risk of cancer recurrence world-wide.