Human papilloma virus in head and neck cancer: the need for a standardised assay to assess the full clinical importance.

Recent studies have revealed an important and intriguing role for human papillomavirus (HPV) in head and neck squamous cell carcinoma (HNSCC). There are indications that the prevalence of HPV-positive HNSCC has recently increased, and genetic analyses point to a completely distinct class of HNSCCs. Most studies suggest that patients with this type of tumour have a better prognosis and some argue that an adjusted therapeutic approach is needed. One crucial point in the research of HNSCC-HPV involvement has often been neglected, which is the lack of a standardised assay to detect HPV. This has resulted in a considerable variation in the frequency of HPV-positive tumours between studies reported thus far. Especially for PCR-based tests, the risk exists that the assay is too sensitive and detects virus without implying a causal involvement in HNSCC. A reliable algorithm to detect a clinically relevant HPV infection in formalin-fixed paraffin embedded tissue has recently become available. Here, we address important biological and analytical aspects of HPV involved in the development of HNSCC and it is emphasised that a standardised HPV assay is a prerequisite for assessing the clinical importance of a HPV infection in HNSCC.