HPV Mediated Head and Neck Cancer

The epidemiology of head and neck squamous cell carcinomas (HNSCC), primarily those of the oropharynx, has changed dramatically over the last two decades. Specifically, HNSCC appears to be a distinct entity that is related to infection by human papilloma virus (HPV)(Vokes et al., 2015) (Fakhry et al., 2008). Moreover, the incidence of HPV-associated oropharyngeal (OP) cancers is rising, likely as a consequence of changing life styles and sexual behaviors. These tumors appear to be biologically and clinically distinct from other HNSCC tumors affecting predominantly middle-aged white men having no or only a brief history of tobacco consumption. The cell cycle regulatory protein, p16, is usually over expressed in HPV-OPSCC, and its detection using immunohistochemistry and in situ hybridization is a reliable surrogate marker for the disease (Ang et al., 2012). When compared to traditional head and neck cancer that is associated with the repeated insult of tobacco use, HPV-related OPSCC has a favorable natural history and is more responsive to treatment. As a result, patients with this cancer have improved long-term survival and consequently are more likely to experience chronic therapy-induced morbidity (Ang et al., 2012). The purpose of this thesis is to provide a comprehensive review of the molecular mechanisms that underlie HPV-mediated OPSCC, and the licensed prophylactic HPV vaccinations available, and to discuss the current thoughts on whether to deescalate potentially damaging treatments in these patients