Polymorphisms of Mismatch Repair Pathway Genes Predict Clinical Outcomes in Oral Squamous Cell Carcinoma Patients Receiving Adjuvant Concurrent Chemoradiotherapy

Background: We aimed to investigate the association between single-nucleotide polymorphisms (SNP) in mismatch repair (MMR) pathway genes and survival in patients with oral squamous cell carcinoma (OSCC) who received adjuvant concurrent chemoradiotherapy (CCRT). Methods: Using the Sequenom iPLEX MassARRAY system, five SNPs in four major MMR genes were genotyped in 319 patients with OSCC who received CCRT treatment. Kaplan–Meier survival curves and Cox proportional hazard regression models were used to assess overall survival (OS) and disease-free survival (DFS) among MMR genotypes. Results: The results of Kaplan–Meier survival analysis revealed that the MutS homolog 2 (MSH2) rs3732183 polymorphism showed a borderline significant association with DFS (log-rank p = 0.089). Participants with the MSH2 rs3732183 GG genotype exhibited a relatively low risk of recurrence (hazard ratio (HR) = 0.45; 95% confidence interval (CI) = 0.22–0.96; p = 0.039). In addition, the MutL homolog 1 (MLH1) rs1800734 GG genotype carriers exhibited higher OS (HR = 0.52, 95% CI = 0.27–1.01; p = 0.054) and DFS (HR = 0.49, 95% CI = 0.26–0.92; p = 0.028) rates. Conclusions: Our results indicated that the GG genotypes of MSH2 rs3732183 and MLH1 rs1800734 are associated with relatively high survival in OSCC patients treated using adjuvant CCRT. These polymorphisms may serve as prognosis predictors in OSCC patients.