Osteopontin as biomarker in early invasion by squamous cell carcinoma in tongue

BACKGROUND: Osteopontin (OPN) expression in squamous cell carcinoma (SCC) of the tongue has not been clearly elucidated. METHODS: We selected 46 cases of tongue SCC and investigated the expression of OPN by immunohistochemical staining. The immunopositive reaction and score for each case were semiquantitatively evaluated. RESULTS: Scores were significantly higher in carcinoma nests than in neighboring normal epithelium or epithelial dysplasia. The OPN was expressed clearly in the cytoplasm of carcinoma cells. In cases of early invasive carcinoma, in particular, expression of OPN showed a remarkable increase at the invasion front compared with the non-invaded regions. However, there was no significant correlation between expression of OPN in the primary tumor nest and lymphatic metastasis, recurrence, or survival rate. CONCLUSION: This suggests that OPN is a useful biomarker of early invasion by SCC in tongue.