Human papillomavirus detection in oropharyngeal squamous cell carcinoma using p16 immunohistochemistry

Introduction: Oral cancer ranks third among all cancers in the Indian population with approximately 45% of call cancer cases in India being diagnosed as oral cancer, among which 20%-50% of the cases are observed to be associated with human papillomavirus (HPV) infection. Aim: This study aims to detect and evaluate the presence of p16 in oropharyngeal squamous cell carcinoma (OPSCC) patients using immunohistochemistry (IHC). Materials and Methods: This study was based on samples collected from 21 patients with primary OPSCC who were diagnosed and treated during the period of December 2017-March 2018. Inclusion criteria were complete clinicopathologic data, adequate clinical follow-up, and availability of sufficient paraffin-embedded tumor material. HPV immunoreactivity was further investigated by means of IHC using p16 as a marker. Results: IHC results revealed p16 positivity in six OPSCC cases. There was no statistically significant association of the p16 positivity of HPV with the age, gender, or site. Conclusion: Our results suggest that IHC-based detection of p16 provides a suboptimal prognostic information if not combined with detection of HPV DNA. Although p16 expression and HPV DNA infection are correlated with HPV-associated OPSCCs, neither of the tests alone is the optimal method for HPV status detection.