Head and neck pathology: poster#181 p16 expression in subsets of head and neck squamous cell carcinoma reported in Kenyatta national hospital Nairobi, Kenya

Abstract

Background: Human papilloma virus associated HNSCC differ from the non HPV-associated HNSCC in that HPV-HNSCC affects younger patients and has better prognosis. These subgroups cannot be readily differentiated on H/E; however, P16 immunohistochemistry can be used to separate these tumours. Data on HPV associated HNSCC from our region is lacking.

Objective: To determine p16 expression and prevalence of HPV associated tumours in subsets of HNSCC at Kenyatta National Hospital (KNH).

Methods: A hundred and three HNSCC cases diagnosed from 2008 to 2013 were analyzed for P16 expression by IHC on FFPE blocks.

Results: Of the 103 cases, males were 73.8% while females 26.2%. Mean age was 57.4 years. Most tumours were well differentiated (63.1%), then moderately differentiated (28.2%), while 8% were poorly differentiated. Immunohistochemistry was done, of which 14.6% were positive for P16. Oral cavity had the highest (46.67%), then larynx (26.67%) and pharynx (26.67%). The majority of p16 positive HNSCC were found amongst males 66.7%. Poorly differentiated tumours had increased risk of being HPV associated (OR 2.1, 95% C.I 0.4-11.9).

Conclusion: HNSCC were more common in males, the majority being from the oral cavity. The overall HPV prevalence was 14.6% with poorly differentiated tumours having an increased risk of HPV association.