The incidence of head and neck cancer (HNC) has been gradually increasing over the last 3 decades. Although certain subsets of HNC (such as larynx cancer) have decreased in incidence in parallel with the reduction in smoking, rates of oral cavity tumors (including tongue and tonsil) have risen among young (<45 years old) men and women. In addition to the classic risk factors of tobacco and alcohol use (that used to be responsible for the majority of HNC) recent data have linked infection with a virus to cases of HNC especially from the oral cavity and related sites. The virus strains responsible belong to the human papillomavirus family (HPV). HPV is the main cause for cervix cancers in women, and the HPV subtypes associated with HNC are rather similar with those causing cervical cancer. Subtype HPV16 accounts for the majority of HPV-positive cases (> 65% of oral tumors, >80% of oropharynx cancers, and 70% of laryngeal cases), with HPV18 having a far second place (around 5-8% of HPV-positive cases). Epidemiological data seem to suggest that sexual transmission is important but other transmission routes are under investigation.
