Human papillomavirus DNA in oral squamous cell carcinomas and normal oral mucosa

To elucidate the putative etiologic role of human papillomaviruses (HPV) in oral carcinogenesis, a comparative study was carried out on 62 tissue specimens of oral squamous cell carcinoma (OSCC) and on 62 specimens of histologically normal oral mucosa obtained from the individuals who matched the subjects with OSCC in age, gender, localization of obtained tissue specimens, drinking and smoking habits. Internal control amplification showed that amplifiable DNA was recovered from 59/62 and 61/62 tissue samples of OSCC and normal oral mucosa, respectively. The amplification with two different HPV L1 and one HPV E6 consensus primer sets showed the presence of the HPV DNA genotypes 16, 33, 58 in 5/59 (8.4%) OSCC specimens and HPV genotypes 11, 16, 31, 68 in 4/61 (6.6%) tissue samples of normal oral mucosa tested. In the study in which a comparative examination of the presence of HPV DNA was for the first time performed on the tissue samples of the patients with OSCC and the age- and gender-matched control subjects there was no significant difference in the prevalence of HPV DNA among both study groups. Our results suggest that occasional findings of HPV DNA in OSCC tissue specimens may be the result of an incidental HPV colonization of oral mucosa, rather than of viral infection, and that HPVs play a limited role in the etiopathogenesis of the majority of OSCC.