Clinical Implications of Mismatch Repair Status in Patients With High-risk Stage II Colon Cancer

Background/Aim: This study evaluated the clinical significance of the mismatch repair (MMR) status and prognostic factors in patients with high-risk stage II colon cancer (CC). Materials and Methods: This was a retrospective analysis of 237 patients diagnosed with high-risk stage II CC who had test results for MMR status. Results: Among the 237 patients, 76 (32.1%) were identified as having a microsatellite instability-high (MSI-H) status. No significant differences were identified in disease-free or overall survival according to the MMR status. Moreover, no association was found between the use of adjuvant chemotherapy and survival outcomes of the MSI-H group. In a multivariate survival analysis, the primary tumor location (right-sided versus left-sided, hazard ratio(HR)=0.172, p=0.003) and T-stage (HR=4.764, p=0.005) were identified as independent prognostic factors for disease-free survival. Conclusion: The present study found that the MMR status was neither prognostic nor predictive in patients with high-risk stage II CC.