Epidemiology of head and neck cancer.

Epidemiologic considerations which are pertinent to cancer of the head and neck are broad and varied. Cigarette smoking continues to be the major cause of head and neck neoplasms. Occupational and environmental exposures to carcinogens have been well identified. Tumors may develop as a result of medical therapies. Susceptibility on a genetic basis has been shown, and the role of viruses in carcinogenesis has been further documented.