Correlation between laminin-5 gamma2 chain expression and epidermal growth factor receptor expression and its clinicopathological significance in squamous cell carcinoma of the tongue.

Recent investigations have revealed that growth factors may influence the invasive activity of tumor cells. Expression of laminin-5 gamma2 chain (LN-5 gamma2) 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 gamma2 expression was clearly demonstrated in the cytoplasm and EGFR in the cell membranes of cancer cells. A significant increase in positivity for LN-5 gamma2 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 gamma2 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 gamma2 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 gamma2 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 gamma2.