Immunohistochemical expression of p16 and p53 in oral and oropharyngeal squamous cell carcinoma

Background Squamous cell carcinoma (SCC) is the most common cancer of the head and neck region with considerable morbidity and mortality. Human papilloma virus (HPV) was identified as a cause of SCC in the head and neck region, especially at oral and oropharyngeal areas. P16 is a tumor-suppressor gene that is used as a surrogate marker for HPV. The p53 gene is the guardian of the genome and the most commonly mutated gene in cancers. The p53 pathway is affected profoundly by HPV protein products. This study aims at exploring the expression of p16 and p53 in oral and oropharyngeal SCC in Egyptian patients and correlating their expression with the relevant clinicopathological parameters. Materials and methods Forty-four paraffin blocks of oral and oropharyngeal SCC were collected with their clinicopathological data and immunostained for p16 and p53. Results p16 was overexpressed in 27/44 cases (61.4%) and was related to a lower tumor grade ( P <0.001), a smaller tumor size ( P =0.001), a negative nodal status ( P <0.001), and an early stage ( P <0.001). p53 was expressed in 19/44 cases (43.2%) and was related to a high grade ( P <0.001), a larger tumor size ( P =0.005), a positive nodal status ( P <0.001), and an advanced tumor stage ( P <0.001). p16 was inversely related to p53 ( P <0.001). Conclusion HPV is related to favorable prognostic factors in oral and oropharyngeal SCC, whereas p53 is related to adverse prognostic parameters. It seems that two major pathways are operable for oral and oropharyngeal SCC genesis, and one of them is HPV related. Further studies are needed to confirm this hypothesis.