Effect of c-Met expression on survival in head and neck squamous cell carcinoma

The proto-oncogene c-Met has been suggested to be associated with progression of squamous cell carcinoma of the head and neck. The aims of the present study were to assess the prevalence of c-Met expression in oral squamous cell carcinoma (OSCC) and to verify whether c-Met can be considered a marker of prognosis in these patients. In a retrospective study, a cohort of 84 OSCC patients was investigated for c-Met expression and its cellular localization by immunohistochemistry. After grouping for c-Met expression, OSCC patients were statistically analyzed for the variables age, gender, histological grading, tumor node metastasis, staging and overall survival rate. Univariate and multivariate statistics were used for data analysis. Sixty-nine cases (82.2%) of OSCC showed immunopositivity, with a mainly membranous expression and scattered areas also showing a cytoplasmic localization, whereas 15 cases (17.8%) did not show c-Met. No statistical association was found between c-Met expression and any variables considered at baseline, apart from the higher number of c-Met positivity in females (p = 0.026). Among positive tumors, well-differentiated areas showed low or absent cytoplasmic expression, while low-differentiated areas showed both membranous and cytoplasmic positivity. In terms of prognostic significance, c-Met expression was found to have an independent association with a poorer overall survival rate (p = 0.036). On the basis of these results, it is possible to suggest c-Met as an early marker of poor prognosis, a hallmark of aggressive biological behavior in OSCC, suggested to be useful in identifying cases of OSCC before the relapse.