ABSTRACT
Background: An increase in oral squamous cell carcinoma (OSCC) cases was observed despite the reduction inexposure to classic risk factors. Although the exact cause of this trend remains unknown, epigenetic factors couldbe contributing to an increased occurrence of these tumors. This study aims to assess the influence of PMS2 pro-tein immunoexpression on the prognosis of patients with OSCC.Material and Methods: This study comprised 76 cases of OSCC treated between 2011 and 2016. Immunohisto-chemical staining for PMS2 was performed. For evaluation, 10 fields per histological section were photographed ata 400x magnification and positively-stained cells were counted with Image J. Mann-Whitney and Kruskal-Wallistests were used to compare the immunolabeling pattern with the clinical-pathological and prognostic characteris-tics. Survival analysis was performed with Chi-square, Long-Rank Mantel-Cox and Cox regression tests (p<0.05).Results: An overexpression of PMS2 was observed in N0/1 tumors and in oral cancers found in unusual locations.In patients ≤60 years of age, high levels of PMS2 (>60%; p=0.041) were associated with low survival (p=0.029).In multivariate analysis, surgery combined with chemotherapy (p=0.030) and high PMS2 immunoexpression(p=0.042) significantly increased the risk of death for ≤60 years old patients Conclusions: The findings of this study indicate that PMS2 can be a potential prognostic protein marker in OSCCpatients 60 years of age and younger.(AU)