Tonsillar Cancer

Abstract

Tonsillar cancer is the most common site of oropharyngeal squamous cell carcinoma (OSCC) and is associated with oncogenic human papillomavirus (HPV) infection in about ≧50% of the cases. The most common high-risk type is HPV16. Increased incidence of tonsillar and base of the tongue cancer has been observed over the past decade in opposition to a decreasing incidence of other head and neck cancers. Sexual behaviors seem to be associated with HPV-related OSCC and most of these individuals lack the classical risk factors smoking and alcohol abuse. The natural history of oral HPV infection is still under investigation. PCR and/or in situ hybridization in combination with p16 immunohistochemistry can be used to detect HPV in tumor tissue to distinguish HPV-related and HPV-unrelated OSCC. However, until now no standard procedure is in clinical use. The biology of HPV-positive OSCC is distinct. This can be demonstrated by differences in clinical presentation, cancer stage, histopathology, expression of cell cycle-related proteins, prognostic biomarkers and genetic changes. The distinct biological behavior leads to differences in outcome and HPV-related OSCCs have a significant favorable prognosis. This might be in part the result of a better response to chemotherapy and irradiation. Clinical trials have to stratify for HPV status, which is now the most promising biomarker for treatment decisions in OSCC.