When saliva meets acid: chemical warfare at the oesophagogastric junction

In the Western world at least, most upper gastrointestinal cancers now arise from the mucosa near to the oesophagogastric junction. Research into the mechanism of the development of adenocarcinoma at the oesophagogasiric junction has mainly focused on the noxious effects of acid and bile. There is however an alternative concept for explaining the location of adenocarcinomas: the cancers are occurring at the anatomical site where saliva encounters acidic gastric juice and their interaction generates reactive nitrogen species which are potentially mutagenic and carcinogenic. At present, it is unclear whether the active nitrite chemistry is exerting detrimental effects on the surrounding tissue but it is important to investigate this possibility as it could reveal new ways of preventing and treating the high prevalence of disease occurring at this anatomical site.