Epidemiology and prevention of esophageal cancer

The aim of the study is to analyze incidence and mortality of esophageal cancer (EC) in the world and Russia; conduct a systematic review of literature of eC causes. Material and Methods. GlOBOCAN, Cancer Incidence in Five Continents and the annual Directories of Cancer Incidence and Mortality in Russia (MNIOI P.A. Hertsen) were used; a systematic search of the published papers on EC risk factors was carried out in the PubMed and Cochrane library databases. Results. EC is characterized by pronounced geographic variability in incidence. High incidence is noted in China, Mongolia, Iran. In Russia incidence of EC is low. In some regions, however, incidence is twice as high as in Russia overall. In the world, 85 % of EC cases have the histological structure of squamous cell carcinoma (SCC) and 14 % – adenocarcinoma (AC). SCC is more common in the countries of east, south and Central Asia, AC prevails in countries of north america, Western and northern europe. the incidence of SCC is decreasing, while incidence of aC is increasing. The main risk factors for SCC are smoking, consumption of alcohol, hot tea, opium, exposure to indoor biomass (wood) smoke, and dietary deficiency in vitamins and minerals. The main risk factor for AK is overweight. The risk of AC is increased in people with Gastro–eesophageal Reflux (GER) and Barrettes esophagus (BE). Molecular signatures caused by EC risk factors have been identified, including mutations, associated with tobacco smoking, alcohol consumption and opium use. Mutations caused by enzymes of the APOBEC family have also been discovered. Preventive measures aimed at reducing the prevalence of SCC risk factors, in particular, control of tobacco smoking, consumption of alcohol, diet modification have already led to a decrease in the incidence of EC. However, there remains a need to continue active preventive work, taking into account regional patterns. Prevention of AK, which should include control of excess weight, timely diagnosis and treatment of gastroesophageal reflux GER and BE, is not yet very effective. Conclusion. The described risk factors and associated mutational signatures do not explain the pronounced geographic variability in EC incidence. Further studies are needed to search for unknown carcinogenic factors with a non-mutational, but epigenetic mechanism of action.