Effect of p63 Expression on Survival in Oral Squamous Cell Carcinoma.

Background: P63 is the protein codified by p63 gene, a p53 gene homolog, known for its pivotal role in cell cycle regulation, and involved in the tumor differentiation. Aims of the present study were to assess the frequency and pattern of p63 protein expression in oral squamous cell carcinoma (OSCC) in relation to the main tumour characteristics and to verify whether p63 can be considered a marker of prognosis in patients with OSCC. Material and Methods: In a retrospective study, a cohort of 64 OSCC patients was investigated for p63 protein expression and its cellular localization by immunohistochemistry (monoclonal mouse anti-human p63 protein-clone 4A4). After grouping by p63 expression, OSCCs were statistically analyzed for the variables age, gender, histological grading (G), TNM, staging, recurrence, and overall survival rate. Results: The overall frequency of p63 overexpressed was of 57.8 percent. Various p63 staining patterns were observed according to G score, with a significant correlation between p63 overexpression and the lowest G score (P < 0.0001). No statistically significant difference was found between p63 pattern expression and age, sex, staging. OSCC patients with p63 overexpressed were found to have a poorer survival rate with respect to OSCCs with a normal pattern of expression (P = 0.024). Conclusions: On the basis of these results, it is possible to suggest p63 pattern expression as a reliable indicator of histological grading and an early marker of poor prognosis.