Cancer of the Oesophagus in Africa, Population Susceptibility, and Preventive Intervention: A Literature Review

Squamous cancer of the oesophagus has been, for almost a century, a major cause of morbidity and mortality in East and Southern Africa, and has been referred to as endemic in many high-incidence regions. Uncertainty about aetiology has inhibited effective preventive initiatives. The aims of this study are to assess why some African regions and countries have a very high incidence of oesophageal cancer; to assess evidence-based associations and risk factors for population susceptibility and for individual susceptibility; to identify which of these are amenable to change; to put forward possible strategies to achieve change. A literature review identified the well-evidenced associations with high incidences of squamous oesophageal cancer to be maize, maize meal, and tobacco. A predominantly maize-based diet, and high use of maize meal are associated with population susceptibility. Tobacco is associated with individual susceptibility within a susceptible population. Alcohol, polycyclic aromatic hydrocarbons and wild vegetables are possible risk factors; other proposed risk factors are improbable. Possible actions are discussed for countries where there is a very high incidence of squamous cancer of the oesophagus. Measures to reduce population susceptibility include regulation of commercially produced maize meal to reduce content of free fatty acids at the time of consumption and supplementation of the diet with omega-3 fatty acid. Fortification of maize meal with zinc and selenium, and health education about production and consumption of fruit and vegetables may be helpful. Legislation to reduce tobacco consumption will reduce individual susceptibility.