ABSTRACT
Head and neck cancer is a heterogeneous group of tumours when considering histopathology, prognosis, and different incidence rates worldwide. They are most often squamous cell carcinomas (more than 95%) and can arise from multiple anatomic subsites in the head and neck region. The region where the tumours arise is characteristically small. This means that the growing tumour mass itself can negatively affect important tissues and structures in the region, which are responsible for important physiologic functions, such as respiration, eating, and speaking. Severe debilitating consequences may also result from locoregional treatment as executed by surgery and radiotherapy because of the small distances between important structures and the difficulties of avoiding these from being affected by treatment. The risk factors for development of cancers in the oral cavity, oropharynx, hypopharynx, and larynx include the major causes of tobacco use and alcohol. However, a changing panorama with respect to pathogenesis and incidence has occurred over the last decades. Human papillomavirus (HPV)-related tumours are now seen increasingly, mostly in the oropharynx. These tumours display a different molecular phenotype, respond better to radiotherapy or cytostatic therapy, have a better prognosis, and have dramatically changed research directions in academic institutions. Traditional treatment modalities are currently being modified; however, new ones (such as immunotherapy in the form of vaccination) are also being developed.
