Microsatellite Instability in Greek Colorectal Carcinoma Patients: Clinicopathological and Molecular Correlations

Background/Aim: In the present retrospective study, we assessed the molecular profile and clinicopathological correlations of Greek colorectal carcinoma (CRC) patients. Patients and Methods: Data from 157 CRC patients were collected. High Resolution Melting Analysis and Pyrosequencing/Sanger sequencing were applied to identify KRAS, BRAF, NRAS mutations and microsatellite instability (MSI) status. Immunohistochemistry was performed to characterize the associated Mismatch Repair Protein loss. Statistical calculations were performed using the statistical package SPSS v21.0. Results: KRAS mutations were detected in 39.3% of cases, BRAF in 10.9% and NRAS in 4.9%. MSI status was recognized in 11.5% of CRC patients and was associated with right colon tumors. MSI phenotype was inversely correlated with stage, N status and KRAS mutations and positively correlated with BRAF mutations. Conclusion: MSI positive CRCs in the Greek population are more often right-sided, free of metastasis, KRAS wild type and BRAF mutated. Providing more detailed clinicopathological and molecular data for specific populations will enable better clinical management and individualized therapy in the future.