Review article: is there a common principle in the development of gastrointestinal cancers? Stem cells in the origin of cancer

Background Accumulating evidence, outlined in this review, at last provides some elucidation of the orgin of gastrointestinal epithelial tumours. Methods New techniques, such as following the process of crypt or gastric gland purification following mutation in genes encoded by the mitochondrial genome, have shown that mutations spead within the proliferative unit, either gastric gland or intestinal crypt, by clonal purification or monoclonal conversion. Spreading otside the crypt or gland then takes place by fission. Results Future research should focus on the mecanisim by which mutated stem cells colonize crypts, and on the mechanisms of crypt fission itself.