High‐risk human papilloma virus was not detected in a Norwegian cohort of oral squamous cell carcinoma of the mobile tongue

Abstract

Abstract Objectives The presence of and the causative role of high‐risk human papilloma virus (HPV) is a subject of controversy in oral squamous cell carcinoma (OSCC). The disagreement can be related to the misclassification of OSCC as oropharyngeal squamous cell carcinoma and/or lack of standard detection methods. This study aimed to examine the presence of transcriptionally active high‐risk HPV in a homogenous Norwegian cohort of primary and second primary OSCC of the mobile tongue (oral tongue squamous cell carcinoma—OTSCC). Methods Tissue microarrays containing formalin‐fixed and paraffin‐embedded cores of 146 OTSCC from the anterior 2/3 of the tongue (n = 128 primary and n = 18 second primary) from a multicentric Norwegian cohort were examined for the presence of high‐risk HPV by DNA‐ and RNA‐in situ hybridization (ISH) assays and p16 immunohistochemistry. Results Transcriptionally active HPV (E6/E7 mRNA) was not identified in any of the OTSCC specimens. In parallel, no tumors were positive for HPV by DNA ISH. Although, 61 (42%) OTSCC demonstrated p16 positivity with varying staining intensity and subcellular localization, only two cases demonstrated strong and uniform p16‐staining (both cytoplasmic and nuclear) in >70% of cancer cells. The absence of transcriptionally active high‐risk HPV in this cohort of OTSCC indicates that high‐risk HPV is an unlikely causative factor in the present material.

Keywords

• cancer of head and neck
• cancer of the mouth
• human papilloma virus
• immunohistochemistry
• in situ hybridization
• squamous cell carcinoma