title: [Serrated precursor lesions].
abstract: The so-called serrated pathway has in recent years been well established as a second route of colorectal carcinogenesis. Sessile serrated polyps, especially sessile serrated adenomas (SSA) and traditional serrated adenomas (TSA) were identified as precursor lesions of this pathway. Activating mutations in either the BRAF (in SSAs) or the KRAS oncogene (in TSAs) have been determined as the initiating molecular alterations, followed by epigenetic methylation of CpG islands in promoter regions of genes which are implicated in cell cycle control or DNA repair. These findings have led to a paradigm shift in gastrointestinal pathology as lesions without cytological dysplasia, such as SSAs and certain forms of hyperplastic polyps, are now accepted to be precancerous lesions. In addition, carcinomas that have developed through the serrated pathway of colorectal carcinogenesis show varying biological behavior relevant for the clinical management of these tumors depending on the molecular aberrations.
authors.affiliation: Institut für Pathologie, Universitätsklinikum Carl Gustav Carus, TU Dresden, Fetscherstr. 74, 01307, Dresden, Deutschland. gustavo.baretton@uniklinikum-dresden.de
authors.forename: G B
authors.initials: GB
authors.lastname: Baretton
authors.forename: D E
authors.initials: DE
authors.lastname: Aust
mesh_terms: D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D003111:Colonic Polyps / Q000235:genetics* / Q000473:pathology*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology*; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation / Q000235:genetics; D004252:DNA Mutational Analysis; D044127:Epigenesis, Genetic / Q000235:genetics; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D011230:Precancerous Conditions / Q000235:genetics* / Q000473:pathology*; D011379:Prognosis; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000235:genetics; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins / Q000235:genetics
chemical_list: C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins