Head and neck cancer: a global perspective on epidemiology and prognosis.

Head and neck cancers (ICD-9 categories 140-149 and 161) are common in several regions of the world where tobacco use and alcohol consumption is high. The age standardized incidence rate of head and neck cancer (around 1990) in males exceeds 30/100, 000 in regions of France, Hong Kong, the Indian sub-continent, Central and Eastern Europe, Spain, Italy, Brazil, and among US blacks. High rates (> 10/100,000) in females are found in the Indian sub-continent, Hong Kong and Philippines. The highest incidence rate reported in males is 63.58 (France, Bas-Rhin) and in females 15.97 (India, Madras). The variation in incidence of cancers by subsite of head and neck is mostly related to the relative distribution of major risk factors such as tobacco or betel quid chewing, cigarette or bidi smoking, and alcohol consumption. Some degree of misclassification by subsites is a clear possibility in view of the close proximity of the anatomical subsites. While mouth and tongue cancers are more common in the Indian sub-continent, nasopharyngeal cancer is more common in Hong Kong; pharyngeal and/or laryngeal cancers are more common in other populations. While the overall incidence rates show a declining trend in both sexes in India, Hong Kong, Brazil and US whites, an increasing trend is observed in most other populations, particularly in Central and Eastern Europe, Scandinavia, Canada, Japan and Australia. The overall trends are a reflection of underlying trends in cancers of major subsites which seem to be related to the changing prevalence of risk factors. The five year relative survival varies from 20-90% depending upon the subsite of origin and the clinical extent of disease. While primary prevention is the potential strategy for long term disease control, early detection and treatment may have limited potential to improve mortality in the short term.