p16 status of oropharyngeal and oral cavity squamous cell carcinomas: A single institution experience

Abstract

Introduction/Objective. New World Health Organization Classification of Head and Neck Tumours from 2017 has introduced significant changes, mainly considering tumors in oropharyngeal region. New entities of HPV positive and negative squamous cell carcinomas have been acknowledged, not only based on presence of active viral infection and different tumor markers expression, but also because of their different histopathology, staging assessment and prognosis. A retrospective study has been conducted, in order to determine p16 positivity in squamous cell carcinomas in oropharynx and in oral cavity, and to see whether they differ in gender and age distribution. Methods. Presence of viral infection was verified based on p16 immunochemistry staining, p16 being the surrogate marker for HPV infection. 177 cases of squamous cell carcinomas in oropharynx and oral cavity, found in archives of Histopathology laboratory of Clinic for Otorhinolaryngology and Maxillofacial Surgery, Clinical Centre of Serbia have been revised. Results. Out of 177 cases, 50 (28.2%) were p16 positive. Compared with carcinomas in oral cavity, p16 carcinomas were significantly more common in oropharynx (34.3% in oropharynx, compared to 10.3% in oral cavity). Carcinomas in both regions were mostly associated with male gender (88.1% of all cases were in males), but p16 positivity was more common in females (11 out of 21 cases, 52.4%). The most common location of p16 positive carcinomas were palatine tonsils (41.03% of tonsillar carcinomas were p16 positive). Conclusion. P16 positive squamous cell carcinomas were the most numerous in oropharynx, i.e. palatine tonsils, and were more common in females