Epidemiology and Aetiology of Head and Neck Cancers

Abstract

Malignant neoplasms of the head and neck are among the most common in the world and constitute a major public health problem in most countries. Over 90 % of these are squamous cell carcinomas arising in the mucous membranes of the upper aerodigestive tract (UADT). Their epidemiology and aetiology are considered in detail. We separate nasopharyngeal cancer, because it has a specific aetiology related to Epstein–Barr virus (EBV) infection and dietary carcinogens. We then add those sites with the common major risk factors of alcohol, tobacco (including betel quid/areca nut habits), poor dentition and diets poor in antioxidants and vitamins and an increasingly recognised role for human papillomavirus (HPV). By simplistically adding age-standardised rates together, collectively these UADT sites of the oral cavity (including the tongue), nasopharynx, other pharynx and larynx have a male incidence/mortality of 14.3/7.9 and for females of 4.4/2.3 cases per 100,000 pa. This ranks UADT cancer as the sixth most common site for men and eighth for women across the world. If the oesophagus were to be included as another alcohol- and tobacco-related cancer, the rates add to 23.3/15.6 and 7.5/5.0, respectively. These cancers—which might be termed cancers of the mouth, pharynx, throat and gullet—then rank second only to lung cancer in men, and fourth after breast, uterine cervix and large bowel in females, worldwide. Detailed data are presented on geographical, ethnic, gender and time differences. The highest rates in the world are found in Melanesia, South Asia, parts of France and much of Eastern Europe and the former Soviet republics. Whilst the rates are now trending downwards for the “traditional” alcohol- and tobacco-related cancers in much of the developed world, the numbers remain high and constitute a considerable personal and public health burden. Many areas are showing rising trends, particularly for oropharyngeal cancer, with a shift to involvement of younger individuals. This, and the fact that survival rates have improved little, except for the most sophisticated multidisciplinary treatment centres, emphasises the need for effective primary and secondary prevention strategies—and for improved public policy to implement these.