Low prevalence of human papillomavirus infection in the healthy oral mucosa of a Northern Italian population.

Oral cancer is the sixth most common malignancy in developed countries, representing almost 3% of malignant tumors. Tobacco use and alcohol consumption are well-established risk factors. However, the observation that most patients with oral cancer have not been exposed to these risk factors suggests that additional causes may promote oral carcinogenesis. A link has been suggested between human papillomavirus (HPV) and oral cavity cancer but the significance of HPV contribution to oral carcinogenesis as well as the prevalence of HPV infection in normal oral cavity mucosa remains debated. Methods:  In this study, the prevalence of oral HPV infection was evaluated in 81 randomly selected Northern Italian subjects with clinically normal oral mucosa using a nested PCR on DNA extracted by oral smears. Results and conclusions:  No HPV-related lesions were detectable in any of the smears analyzed by cytological approach. nPCR identified HPV DNA in only one (1.2%) of the specimens obtained from clinically healthy oral mucosa and subsequent characterization assigned the positive case to HPV type 90. These data suggest that the incidence of HPV infection in the healthy population might be very low and that other risk factors are likely responsible to promote oral carcinogenesis.