Human papilloma virus status in upper aerodigestive squamous cell carcinoma at Uganda Cancer Institute

Abstract

Introduction: The etiology of Head and Neck Cancers (HNC) was previously largely attributed to tobacco use and alcohol consumption but the role of Human Papilloma Virus (HPV) has gained recent recognition. The HPV related HNC is seen predominantly in the oropharynx, presents at a younger age and has a better prognosis. With a rapidly increasing incidence of these cancers in the developed world, it was important to study HPV in HNC in Uganda. HPV can easily be detected using P16 immunohistochemistry (P16 IHC) as a surrogate marker thus making it suitable for screening. Objective: The study aimed at establishing the frequency and clinical presentation of HPV in upper aerodigestive tract squamous cell carcinoma (UADT SCC) at Uganda Cancer Institute (UCI) using P16 IHC. Methodology: This was a cross sectional study in which all patients with histologically proven squamous cell carcinoma from the oral cavity, oropharynx, larynx and hypopharynx at UCI were recruited. Using a questionnaire, the patients’ demographics and clinical data were collected. Tissue sections from retrieved histology samples were stained by Haematoxylin and Eosin to reconfirm SCC. Subsequently, P16 expression was determined using P16 immunohistochemistry. Data analysis was performed using STATA 13.0. Statistical tests included Fisher’s exact tests. Results: Fifty-nine patients with SCC of the sites of interest were recruited. The majority (59.3%) of the participants were male and over 50 years. Most (59.3%) of the participants were tobacco smokers, 66.1% used alcohol, 52.2% used both while 27.1% used none of the substances mentioned. Only 27.1% of the participants were HIV positive. Most of the tumors were in the larynx (37.3%) and 64.4% were overall TNM stage 4. The overall prevalence of HPV in UADT SCC at UCI was 20.3%, 95% Confidence interval (CI) of 10.9-32.8. The oropharynx had the highest prevalence (30.8%) closely followed by the oral cavity (29.4%). The difference in nodal staging between patients with and without HPV was significant (p value 0.002). The other variables of comparison did not reach statistical significance. Conclusion: The contribution of HPV in UADT SCC at UCI using P16 IHC is significant at 20.3 %. The oropharynx is the most affected site and is closely followed by the oral cavity. Recommendation: Further research with a larger study sample incorporating confirmatory tests for the presence of HPV to validate our study findings is suggested. We should sensitize both medical care providers and the public about the risk factors associated with UADT SCC and HPV.