Prevalence of human papillomavirus in oral squamous cell carcinomas in northern Spain.

The aim of this study was to analyze the prevalence of high-risk HPV in oral squamous cell carcinoma (OSCC) in a northern Spanish population, as well as to ascertain the prognostic role of p16 expression. The examination samples were collected from paraffin tissue blocks, from 125 patients surgically treated between 1996 and 2007. All cases were histologically evaluated, and the presence of HPV was assessed by p16 and p53immunohistochemistry followed by DNA detection by in situ hybridization (ISH) and polymerase chain reaction (PCR) amplification using the combination of consensus primers MY11/GP6 + . Fourteen cases (11 %) were p16-immunopositive, and p53 was scored positive in 73 cases (58 %). Five cases (4 %) showed a simultaneous p16-positive and p53-negative immunostaining. ISH was negative in all the cases. Among the p16INK4a-immunopositive cases, PCR amplification failed to reveal HPV DNA in any tumor samples. There were no statistically significant differences in any clinical or pathological characteristics of the patients regarding p16 expression. T classification, neck-node metastasis, and clinical stage showed outcome relevance. However, no significant differences in cause-specific survival based on p16INK4a were observed. We did not find any high-risk HPV types in our patients, thus, are unlikely that HPV has an important role in the etiology of OSCC. p16INK4a protein was neither an accurate marker of HPV infection nor a prognosis marker in OSCC.