Prevalence of p-16 Positive Laryngeal and Pharyngeal Tumors in Nepalese Population: A Hospital based Cross-sectional Study.

Introduction: P16 overexpression is considered as a good prognostic marker for oropharyngeal squamous cell carcinoma. However, there are very few literatures on the prevalence and outcomes of p16 overexpression in non-oropharyngeal squamous cell carcinoma and benign head and neck tumors. The aim of our study was to estimate the hospital based prevalence of p16 positive laryngeal and pharyngeal tumors and to compare it with the prevalence of p16 expression in the non tumor tissue (tonsils).

Methods: This was a descriptive cross-sectional study. Cases of all genders >15 years presenting with malignant or benign tumors of larynx and all the subsites of pharynx were included in the study for evaluation of p16 expression by immunohistochemistry. Tonsillar tissue of cases undergoing tonsillectomy for recurrent acute tonsillitis were taken as non-tumorous tissue to evaluate for p16 expression.

Results: A total of 48 cases were included in our study with 24 cases having different tumors of head and neck region and 24 cases having recurrent acute tonsillitis who were kept under non-tumor group. Eight cases (33.3%) in the tumor group showed positive stain for p16 in IHC. In non tumor group, 7 cases (29.1%) showed positive IHC staining for p16.

Conclusions: P16 expression can be present in both benign and malignant tumors of various subsites of head and neck region and also in tonsillar tissue affected by inflammation.