[Immunohistochemical expression of p53 protein in squamous epithelial carcinomas and normal and dysplastic epithelium of the mouth cavity].

Routinely formalin-fixed and paraffin-embedded material of 123 squamous cell carcinomas of the floor of the mouth and tongue bordered by non-tumorous mucosa were immunohistochemically investigated for the expression of p53 protein using a panel of four anti-p53 antibodies (CM1, PAb 1801, DO7, PAb240) following wet autoclave antigen retrieval. p53 immunoreactivity was detected in 55-67% of the carcinomas, with the different antibodies used showing a preferential accumulation of the p53-positive tumour cells at the invasive tumour front. In dysplastic and normal epithelium focal or dispersed p53 immunopositivity could be detected in 62-72% and 57-70% of the cases, respectively, regardless of the p53 immunostatus of the carcinomas. No statistically significant correlations between p53 immunophenotype of the tumours and clinico-pathological parameters, or survival of the patients, could be detected statistically. It is concluded that immunohistochemically detectable p53 accumulation in oral cancer might indicate an early stage of carcinogenesis. The immunohistochemical detection of p53 in these tumours, however, is without prognostic significance.