Although the incidence is falling in the UK, the incidence is still high world wide and the environmental factors that predispose are the main reason for this large geographical variation in incidence.
The most important risk factor is smoking, which dramatically increases the risk of head and neck cancer. If smoking is combined with alcohol, the risk increases further.
Various other environmental factors that have been associated with a higher incidence of head and neck cancer are exposure to chromium and nickel dusts and various leather workers and wood workers have rarely been found to have a higher incidence of cancers of the nose or nasal sinuses.
Nasopharynx cancer, which is a slightly unusual subtype of the squamous carcinomas of this region, is related in its incidence to exposure to salty fish in the diet and Epstein-Barr virus infection. It is more common in the Far East.
Squamous head and neck cancer is more common in males.
More recently, cancers of the oropharynx (the tonsil, back of the tongue, and the palate) have been linked to Human Papilloma Virus infection.
Chewing Paan or Beetle Nut, increases the risk of cancer of the tongue, inner cheek and the gums.