KRAS Protein Expression in Oral Squamous Cell Carcinoma: A Potential Marker for Progression and Prognosis

Background Objective: Emerging evidence suggests that KRAS could play an important role in squamous cell carcinoma; however, its role in oral squamous cell carcinoma (OSCC) is largely unknown. The aim of the current study was to investigate the expression of KRAS, Ki-67, Cyclin D1, and Bcl2 in OSCC and their association with clinicopathological features. Methods: Forty paraffin blocks of retrospective histologically diagnosed cases of OSCC and 20 blocks of oral leukoplakia with epithelial dysplasia were obtained from two hospitals between 2018 and 2021. The paraffin-embedded tissue was analyzed for the expression of KRAS for oral epithelial dysplasia and OSCC, and ki-67, Cyclin D1, and bcl2 were analyzed only for OSCC. The results were correlated with each other and with different clinicopathological features and were statistically analyzed. Results: KRAS expression was significantly associated with histological tumor grade, tumor extent, presence of nodal and distant metastasis, pathological stage, and the presence of lymphovascular invasion (P= 0.001, 0.001, 0.001, 0.009, 0.001, and 0.001, respectively). The KRAS expression was positively correlated with the histological grade, tumor extent, nodal status, and the pathological stage (r=0.712, 0.649, 0.646, and 0.865, respectively). A positive correlation was also found with the expression of Bcl2, Cyclin D1, and Ki-67 (r=0.81, 0.723, and 0.698, respectively). The KRAS expression in oral epithelial dysplasia was significantly lower than that in OSCC (P=0.003).Conclusion: KRAS may be a potential prognostic marker for OSCC and may play a role in its progression.