Head and neck cancers (HNC) are a heterogeneous group of cancers arising in the epithelial cells of the mucosal linings of the upper aero-digestive region of head and neck. Histologically more than 90% of head and neck cancers are squamous cell carcinoma (HNSCCs). Anatomically HNSCCs are majorly divided into cancers of the oral cavity, oropharynx, hypopharynx, and larynx (Figure 1), which can be further subcategorized into 14 subsites according to...