Abstract
Cancer of the oesophagus is the ninth most common cancer in the world, but in developing countries, it is ranked fifth. The epidemiolOgical behaviour of oesophageal cancer is marked by large differences in incidence within small geographical areas and sharp changes in incidence over time which suggest an important role for environmental factors. There is considerable epidemiological evidence indicating that alcohol, tobacco, poor nutrition and thermal injury are responsible for the great majority of oesophageal cancers in the Americas, Europe, parts of Africa and Asia and, therefore, control of these factors would lead to a great reduction in the incidence of the disease. Smoking and chewing of opium pyrolysates may be the main cause in high-risk areas of Iran, but the determinants of high risk in China and other populations of the Asian belt remain largely unidentified.