The unveiled reality of human papillomavirus as risk factor for oral cavity squamous cell carcinoma

The prognostic impact of human papillomavirus (HPV) in oropharyngeal cancer is generally acknowledged, and HPV‐status is assessed routinely in clinical practice. Paradoxically, while the oral cavity seems the predilection site for productive HPV‐infections, figures on HPV‐attribution in oral cavity squamous cell carcinoma (OCSCC) differ widely, and prognostic impact is uncertain. Major obstacles are the lack of reproducible assays to detect HPV in nonoropharyngeal cancers, the relatively small cohorts studied and consequently the shortfall of convincing data. In our study, we used a validated, nucleic acid‐based workflow to assess HPV‐prevalence in a consecutive cohort of 1016 OCSCCs, and investigated its prognostic impact. In parallel, we analyzed p16‐immunohistochemistry (p16‐IHC) as surrogate marker for transforming HPV‐infection and independent prognosticator. All OCSCC‐patients diagnosed between 2008 and 2014 at two Dutch university medical centers were included (N = 1069). Formalin‐fixed, paraffin‐embedded (FFPE)‐samples of 1016 OCSCCs could be retrieved. Punch biopsies were taken from the tumor area in the FFPE‐blocks and tested for HPV. P16‐IHC was performed on 580 OCSCCs, including all HPV‐positive tumors. From 940 samples (92.5%), nucleic acids were of sufficient quality for HPV‐testing. In total, 21 (2.2%) OCSCCs were HPV DNA‐positive. All HPV DNA‐positive tumors were E6 mRNA‐positive and considered as true HPV‐positive. There was no difference in survival between HPV‐positive and HPV‐negative OCSCCs. In total, 46 of 580 (7.9%) OCSCCs were p16‐immunopositive, including all HPV‐positive tumors. Survival was comparable in p16‐positive and p16‐negative OCSCCs. To conclude, HPV‐prevalence is very low in OCSCC and neither HPV‐status nor p16‐status affects outcome. Based on these data, determining HPV‐status in OCSCC seems irrelevant for clinical management.
What's new? While human papillomavirus (HPV)‐infection is prognostic for oropharyngeal squamous cell carcinoma (OCSCC), its role and prognostic impact in OCSCC remain uncertain. In the present study, nucleic acid‐based HPV‐testing of a cohort of 1016 tumor samples collected from OCSCC patients diagnosed between 2008 and 2014 reveals very low HPV‐prevalence in OCSCC. In addition, no difference was found in survival between HPV‐positive and HPV‐negative tumors. The findings indicate that HPV is uncommon in OCSCC and, when present, has no impact on survival, providing new and important insight into the ongoing debate regarding the role of HPV in OCSCC.