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

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.

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.

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).

KRAS may be a potential prognostic marker for OSCC and may play a role in its progression.