Background: The recognition of tumor infection by human papilloma virus (HPV) in oropharyngeal squamous-cell carcinoma (OSCC) is emerging as a valid biomarker to more accurate selection of patients for specific treatment, surveillance and tumor staging. To this aim, the HPV detection strategy in OSCC must dissect between HPV that is acting as a driver of malignant transformation, and transcriptionally silent virus involved in productive infection. The aim of this study is to define the better method for the accurate identification of HPV status among OSCC.

Patients and Methods: Thirty-six patients were selected for HPV status assessment combining different methods, such as immunohistochemistry (IHC) for p16, in-situ hybridization (ISH) for high risk (HR)-HPV DNA and HR-HPV E6/E7 mRNA along with real-time PCR of HPV16 E6/E7 mRNA. All these cases were originally classified as HPV negative by DNA-based ISH but p16 positive by the IHC.

Results: Twenty-six cases showed concordance between methods; whereas, nine cases resulted negative for HPV E6/E7 mRNA RT-PCR but positive for HPV E6/E7 mRNA ISH.

Conclusion: By considering that the bright field HPV E6/E7 mRNA ISH could be more sensitive than mRNA-based real-time RT-PCR, and that it provides the precise identification of transcriptionally active HPV infected cells, a randomized analysis to validate the robustness of this preliminary assay will be undertaken.