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) and diets poor in antioxidants and vitamins, and a minor role for Human Papillomavirus (HPV). Collectively, these UADT sites of oral cavity (including tongue), other pharynx, and larynx have a male incidence/mortality of 15.2/8.1 and for females of 4.6/2.4 cases per 100,000 pa. This ranks UADT cancer as the sixth most common site for men, eighth for women. Adding nasopharynx pushes head and neck cancer higher up the scale. If oesophagus were to be included as another alcohol and tobacco-related cancer, the rates add to 28.6/18.9 and 10.1/6.8 respectively. These cancers – which might be termed cancers of the mouth, 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. Many of these areas are showing rising trends, with a shift to involvement of younger individuals. This, and the fact that survival rates have improved little or not at all in much of the world over several decades, emphasises the need for effective primary and secondary prevention strategies – and for improved public policy to implement these.