Assessment and clinicopathological correlation of p16 expression in head and neck squamous cell carcinoma

Oral squamous cell carcinoma is a major cause of death throughout the developed world. It is associated with smoking and alcohol consumption. Human papillomavirus (HPV) type 16 has also been suggested to play a role in etiology of head and neck squamous cell carcinoma (HNSCC). p16 expression is now being used as a surrogate marker of HPV infection in squamous cell carcinoma and provides important prognostic information and future therapy planning.

In this prospective study, total of 75 cases of HNSCC were taken. Tumor grade was determined according to World Health Organization (WHO) criteria. p16 expression was determined by immunohistochemical staining. The obtained results were analyzed and evaluated using Chi-square test (Statistical Package for Social Sciences (SPSS) version 20), value of P <0.05 was taken significant.

Out of 75 cases, 78.7% cases were positive for p16 (inclusive of all grades), while 21.3% cases were negative. Expression of p16 was higher in nonsmokers and nonalcohol consumers and significantly associated with paan chewing habit. No significant correlation was seen with history of abnormal sexual habits, but p16 expression was significantly correlated in cases with multiple sexual partners (P = 0.003), with increasing histological grade (P = 0.045) and in cases with lymph node metastasis (P = 0.03).

As HPV integration with transcription of viral oncoprotein induces overexpression of p16, immunohistochemical expression of p16 can be used as a surrogate marker of HPV. This approach can be implemented in diagnostic laboratories and can provide support for vaccination program in high risk group.