Epidermal growth factor is a single-chain polypeptide consisting of 53 amino acids and has a potent mitogenic activity that stimulates proliferation of various normal and neoplastic cells through the interaction with its specific receptor (epidermal growth factor receptor, EGFR). This interaction plays a key role in tumor progression including induction of tumor cell proliferation. Increased EGFR copy number have been associated with favorable response to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors therapy. In contrast, K-ras mutation has been shown to predict poor response to such therapy. Hence, the goal of this study is to identify the correlation of clinicopathological factors and the up-regulation of EGFR expression and K-ras mutation in oral squamous cell carcinoma. We studied the immunohistochemical staining of EGFR, K-ras mutation detection with PNA-based real-time PCR clamping in 20 specimens of 20 patients with oral squamous cell carcinoma.

The results were as follows.

• 1.

  In the immunohistochemical study of poor differentiated and invasive oral squamous cell carcinoma, the high level staining of EGFR was observed. And the correlation between immunohistochemical EGFR expression and histologic differentiation, tumor size of specimens was significant (Pearson correlation analysis, significance [ r ] > 0.5, p < 0.05).

• 2.

  In the PNA-based real-time PCR clamping analysis, K-ras mutation was not detected in all specimens.

These findings suggest that up-regulation of the EGFR may play a role in progression and invasion of oral squamous cell carcinoma.

Conflict of interest: None declared.