Relevance of human papilloma virus (HPV) infection to carcinogenesis of oral tongue cancer

Human papilloma virus (HPV) infection is controversial as a causative factor in oral tongue cancer. This study aimed to clarify whether HPV directly affects the carcinogenesis and biological behaviour of oral tongue cancer by analyzing HPV prevalence, the physical status of the virus and clinicopathological parameters. Archival tissue was obtained from 36 patients diagnosed with T1 and T2 oral tongue cancer and 25 normal controls. HPV genotyping chip and real-time polymerase chain reaction were used to determine the prevalence, phenotype and physical status of HPV to clarify whether HPV directly affects oncogenesis. The results were also compared with clinicopathological parameters. HPV was detected in 36% (13/36) of oral tongue cancer patients, compared with 4% (1/25) of the control. In the HPV-positive group of oral tongue cancers, HPV-16 was the most common type and its prevalence rate was 85% (11/13). Of the HPV-16 infected oral tongue cancers, the integration rate of HPV-16 was 55% (6/11). The HPV-16 positive group showed shallower stromal invasion than the HPV-16 negative group (p = 0.045). HPV-16 may be one of the causative factors in early squamous cell oral tongue carcinoma and be associated with its depth of invasion.