Prevalence of Human papillomavirus (HPV) and Epstein-Barr virus (EBV) in oral and oropharyngeal squamous cell carcinoma in south-eastern Poland

OBJECTIVE: The aim of this study was to analyze the prevalence of HPV and EBV in oral and oropharyngeal squamous cell carcinoma in south-eastern Poland. The correlation between viral infection, OSCC, alcohol use, tobacco smoking, demographic data (gender, age, place of residence), anatomic location, pre-treatment staging, evidence of metastases to lymph nodes, and grading was also investigated. METHODS: The examination samples were collected from paraffin tissue blocks, from 154 patients. Viral DNA was amplified by the nested-PCR method. RESULTS: HPV DNA was detected in 29.2 % of the tested samples (in 27.4 % of oropharyngeal and in 30.4 % of oral cavity). The HPV type 16 was detected in 15.6 % of all samples, and in 53.3 % of HPV-positive group. In HPV-positive samples from oropharyngeal HPV 16 constitute 76.5 %, and in HPV-positive samples from oral cavity HPV 16 constitute 39.3 %. Mixed infection (more than one type of HPV) was observed in 23.5 and 60.7 %, respectively, and in 46.7 % of all HPV-positive samples, and in 12.3 % of the whole study group. EBV DNA was detected in 27.3 % of the cases and HPV-EBV co-infection in 7.8 % of samples. CONCLUSIONS: In major patients from Southeastern region of Poland with oropharyngeal cancer HPV type 16 was detected but in oral cavity cancer other mixed infections were observed (i.e. 51, 52, 59, 66, 68, 71, 74). HPV 16 was detected more often among patients younger than 50 years of age, whereas the mixed HPV in the group aged 50–59. The pathogenesis of oral squamous cell carcinoma may be connected with EBV infection. Future studies on the mechanisms of HPV/EBV co-infection and/or superinfection and their role in oral squamous cell carcinoma are necessary.