p53 in biopsies of oral squamous cell carcinoma. A comparative study with a malignancy grading system

The relationship between the histological grading of malignancy and p53 protein expression was studied in 40 biopsies of oral squamous cell carcinomas. An immunohistochemical analysis was carried out using the steptavidin method preceded by a treatment with citric acid in a microwave oven. All cases were classified according to the histological malignancy grading system proposed by Anneroth et al. (Scandinavian Journal of Dental Research 1987, 95, 229–249). The expression of p53 was found in 62.5% of the carcinomas studied. Positivity of p53 staining showed a correlation with the histological grade of malignancy and with the degree of keratinisation, nuclear polymorphism and number of mitoses.