Immunohistochemical detection of p53 oncoprotein in human oral squamous cell carcinomas and leukoplakias: comparison with proliferating cell nuclear antigen staining and correlation with clinicopathological findings.

Forty oral squamous cell carcinomas and 20 leukoplakias were examined for expression of p53 oncoprotein using an immunohistochemical technique with BP53-12 monoclonal antibody. Positive staining was found in 21/40 (52%) of the carcinomas and 2/20 (10%) of the leukoplakias. Furthermore, comparison of p53 expression with binding of PC10 monoclonal antibody to proliferating cell nuclear antigen (PCNA) and degree of histological malignancy in terms of invasion and histological differentiation of carcinomas demonstrated a positive correlation in both cases.