P16 detection in benign, precursor epithelial lesions and carcinomas of head and neck

Human papillomavirus (HPV) had recently been implicated in the pathogenesis of Head and Neck SCCs. The biological role of HPV in benign and pre-cancerous lesions is far less studied. p16 is a widely accepted marker to detect immonohistochemically the presence of HPV.

We evaluated, immunohistochemically, expression of p16 in 212 specimens: glottis, supraglottis, oropharynx, nasal/paranasal, with various diagnoses: hyperplasia, polyp/nodule, keratosis, papilloma, inverted papilloma, dysplasia, cancer (SCC). Analysis was completed according to location and disease.

Hyperplasias/polyps were all negative for p16. A small percentage of papillomas was p16+ regardless of their location (12.5 %), the majority of inverted papillomas were p16+ (78.6 %) and statistically significant (p < 0.04). In carcinomas, 18/59 were p16+ (30.5 %): nasal/paranasal SCCs had a significantly higher percentage of p16+ cancer cells compared to glottis (p = 0.009), while tumours of the supraglottis/oropharynx had an intermediate score for p16+ cells (p = 0.07). Dysplasias were p16+ in 9/64 (14 %) regardless of grading (p = 0.03 compared to carcinomas).

p16 was highly detected in inverted papillomas and in certain anatomic sites; however, it failed to be traced in benign lesions and only rarely encountered in dysplasias.