Expression of c-Met Is Different along the Location and Associated with Lymph Node Metastasis of Head and Neck Carcinoma

BACKGROUND: Activation of the c-Met pathway is involved in cancer progression and the prognosis. We aimed to identify any association of c-Met protein expression with a number of clinicopathologic variables including infection of human papillomavirus and Epstein-Barr virus (EBV) in head and neck carcinomas (HNCa). METHODS: Eighty-two cases were enrolled in this study. Expression of c-Met and p16 was investigated immunohistochemically. EBV was detected by in situ hybridization and amplification of the c-Met gene by fluorescence in situ hybridization. RESULTS: The c-Met protein was expressed in 41.5% (34/82), and gene amplification was found in 1.4% (1/71). High expression of c-Met was associated with the primary location of the tumor; the hypopharynx showed the highest expression, followed by the oral cavity, larynx, and nasal cavity. Squamous cell carcinoma expressed c-Met more frequently than undifferentiated carcinoma. Also, p16 immunoreactivity or EBV infection was associated with the tumor location and well-differentiated histologic type, but were not linked to c-Met expression. The patients with positive c-Met expression showed frequent lymph node metastasis. CONCLUSIONS: Activation of the c-Met pathway might be involved in a subset of HNCa. Cases showing positive c-Met expression should be carefully monitored because of the high probability of lymph node metastasis.