HEAD AND NECK CANCER
Squamous carcinomas of the head and neck (a grouping which includes tongue and mouth, nasopharynx, and larynx) are associated with cigarette smoking and alcohol ingestion (although the risk factors for different sites may differ). In addition, infection with human papillomavirus (HPV) is associated with cancers of the oropharynx (D’Souza et al. 2007). Specific head and neck cancers may be associated with familial cancer syndromes such as hereditary non-polyposis colon cancer syndrome and Li–Fraumeni syndrome (larynx) and Fanconi anemia (oral cancer). Foulkes et al. (1996) reported a relative risk of 3.7 for developing head and neck cancer in first- degree relatives of an affected case, but the relative risk was almost 8 if the index case had multiple primaries.
Exome resequencing studies of squamous carcinomas of the head and neck revealed that the most frequently mutated genes were TP53, NOTCH1, CDKN2A, PIK3CA, FBXW7, IRF6, PTEN, and HRAS (Agrawal et al. 2011;
Stransky et al. 2011) and that HPV-associated cancers had a lower overall number of mutations per Tumours. TP53 mutations were not detected in HPV- associated Tumours but were present in ~80 % of HPV-negative Tumours (Agrawal et al. 2011). Overall, it was noteworthy that although head and neck squamous carcinomas are clinically categorized by anatomical location, at a molecular level the presence of TP53 inactivation (through somatic mutation or HPV infection) appears to be a common feature (Stransky et al. 2011).