Recent investigations have revealed that growth factors may influence the invasive activity of tumor cells. Expression of laminin-5 γ2 chain (LN-5 γ2) and epidermal growth factor receptor (EGFR) in squamous cell carcinomas of the tongue in 104 patients with stage II, III, and IVA, B (excluding the cases with distant metastasis) was examined immunohistochemically to determine the correlation between the two molecules and the associations with the clinicopathological features of each tumor. LN-5 γ2 expression was clearly demonstrated in the cytoplasm and EGFR in the cell membranes of cancer cells. A significant increase in positivity for LN-5 γ2 was observed in tumors showing poor differentiation (p < 0.001), infiltrative growth (p < 0.001), and deep invasion (p = 0.038). In a multivariate analysis, increased positivity for LN-5 γ2 was an independent predictor of an unfavorable outcome (p < 0.001). A significant increase in positivity for EGFR was observed in tumors showing infiltrative growth (p = 0.032) and poor prognosis (p = 0.008). The LN-5 γ2 expression was correlated significantly with EGFR expression (p < 0.001). Patients with tumor positivity for both molecules showed the worst prognosis (p < 0.001). LN-5 γ2 overexpression and EGFR overexpression is evident in tumors showing infiltrative growth, suggesting that EGFR may influence the invasive activity of tumor cells through overexpression of LN-5 γ2.

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