Immunohistochemical analysis of expression of tumor suppressor gene p53 protein in oral squamous cell carcinoma. Correlation with histological malignancy.

In a variety of human carcinomas, mutations of tumor suppressor gene p53 protein occur frequently and may lead to overexpression of a longlived mutant form of p53 protein. Using specific monoclonal antibodies, a total of 53 oral squamous cell carcinomas (SCC) were examined immunohistochemically for the expression of p53 protein. The results were as follows:1) Expression of p53 protein was detected in 29 of 53 cases (54.7%) of oral SCC.2) In oral SCC, there was no correlation between p53 protein expression and the degree of histological differentiation or the mode of invasion.3) Expression of p53 protein correlated with the grade of malignancy.4) These results suggest that alteration of the p53 gene occurs frequently in oral SCC and that immunohistochemical studies of p53 protein are valuable in the assessment of early recurrence, prognosis, proliferative activity, and malignancy of oral SCC.