The p53 molecule and its prognostic role in squamous cell carcinomas of the head and neck

Despite intense research, the 5-year survival rate for patients with squamo us cell carcinoma of the head and neck (SCCHN) is still low. Several differ ent factors have been studied in the search for one or more factors that gi ve important prognostic information at the time of diagnosis. Many recent s tudies have focused on the TP53 tumour suppressor gene, analysing its gene status and protein status. When looking at p53 protein expression, using im munohistochemistry, no correlation to patient outcome has been seen for the whole group of SCCHN. However, a significant association between p53 expre ssion and poor patient outcome was found when looking only at patients with laryngeal squamous cell carcinomas. Also, in oral premalignant lesions, ex pression of p53-positive cells in the suprabasal layers of the epithelium h as been seen as an indication of impending malignant development. Concernin g the prognostic significance of mutations in the TP53 gene, results differ . But when restricting analysis to tumours with mutations causing an obviou s change in protein, TP53 mutation was found to be a strong and independent variable for prognosticating survival. This review article gives an up to- date overview of the p53 molecule and evaluates its possible prognostic rol e in SCCHN. Today it is clear that the p53 pathway is very important in SCC HN biology and potentially in its treatment. The function and importance of a few other cell cycle proteins connected to p53 are also discussed.