Immunohistochemical Expression of N-ras Oncogene is a Late Event in Head and Neck Carcinomas.

This study investigated the expression of the N-ras oncogene in routinely processed tissue sections from 133 patients with squamous cell carcinoma of the head and neck (SCCHN) by immunohistochemistry using anti-N-ras monoclonal antibody. N-ras expression was present in 67 of 133 (49.6%) cases. There was a highly significant correlation between N-ras expression and clinical stage of disease (P=0.003). This study confirmed that overexpression of the N-ras oncogene is common in SCCHN and that it may be an important event in the late stage of disease.