Immunohistochemical Study of Expression of Tumor Suppressor Gene p53 Protein in Oral Squamous Cell Carcinoma

In a variety of human carcinoma, mutations of the tumor suppressor gene p53 protein occur frequntly and may lead to overexpression of a long-lived mutant form of p53 protein. Using specific monoclonal antibodies, a total of 53 oral squamous cell carcinoma (SCC) were examined immunohistochemically for the expression of p53 protein. The results were as follows : 1) Expression of p53 protein was detected in 29 cases out of 53 cases (54.7%) of oral SCC. 2) In primary site, expression of p53 protein was frequently seen in tongue cancer (70.6%). 3) In oral SCC, there was no significant correlation between the expression of p53 protein and the stage of the disease, the TNM status. However, the incidence of p53 protein expression correlated significantly with lymph node metastasis. 4) In oral SCC, no correlation was seen between p53 protein expression and the histological differentiation, the mode of invasion. 5) Expression of p53 protein correlated with the grade of malignancy. 6) These results suggest that alteration of p53 gene appears common in oral SCC, and the p53 protein detection by immunohistochemically method was valuable for assessment of the early recurrence, prognosis of patients, and proliferative activity and more aggressiveness with oral SCC.