The most common malignancy of the oral cavity is the oral squamous cell carcinoma (OSCC). P53 gene is commonly mutated tumor suppressor gene in human tumors.

The aim was to determine the immunohistochemical expression of p53 protein in tissue of OSCC and its correlation with clinicopathological parameters.

This is prospective/retrospective study which included 84 patients with a primary OSCC (2003–2006). Paraffin blocks of tumor tissue were obtained from the Center for Pathology. Semi-quantitative assessment of p53 protein expression included the selection of 10 visual fields with approximately 1000 cells in order to determine the percentage of p53 stained tumor cells. According to the percentage of positive tumor cells, the samples were divided into the groups: score 0–4 (depending on reactivity of tumor cells).

Overexpression of p53 protein, i.e. more than 10% positive nuclei of tumor cells were found in 42 of 84 cases (50%). The greatest width as well as thickness of the tumor was found in patients with the highest expression of p53 protein (score 4). It was found a statistically significant effect of p53 protein expression on tumor length and also there was a trend of larger values of all tumor sizes (width, length and thickness) in patients with expression of p53 protein more than 10%. Prognostic significance of p53 overexpression for the OSCC recurrence and/or metastatic disease has not been determined.

The study of the molecular pathogenesis of OSCC could help in prediction of the clinical behavior of the tumor and therapeutic modality of treatment.

Conflict of interest: None declared.