title: Pathogenesis and management of serrated polyps: current status and future directions.
abstract: Hyperplastic or serrated polyps were once believed to have little to no clinical significance. A subset of these polyps are now considered to be precursors to colorectal cancers (CRC) in the serrated pathway that may account for at least 15% of all tumors. The serrated pathway is distinct from the two other CRC pathways and involves an epigenetic hypermethylation mechanism of CpG islands within promoter regions of tumor suppressor genes. This process results in the formation of CpG island methylator phenotype tumors. Serrated polyps are divided into hyperplastic polyps, sessile serrated adenomas/polyps (SSA/Ps), and traditional serrated adenomas (TSAs). The SSA/P and the TSA have the potential for dysplasia and subsequent malignant transformation. The SSA/Ps are more common and are more likely to be flat than TSAs. Their flat morphology may make them difficult to detect and thus explain the variation in detection rates among endoscopists. Challenges for endoscopists also include the difficulty in pathological interpretation as well surveillance of these lesions. Furthermore, serrated polyps may be inadequately resected by endoscopists. Thus, it is not surprising that the serrated pathway has been linked with interval cancers. This review will provide the physician or clinician with the knowledge to manage patients with serrated polyps.
authors.affiliation: Department of Veterans Affairs Medical Center, White River Junction, VT, and The Geisel School of Medicine at Dartmouth Medical, Hanover, NH, USA.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Anderson
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D018256:Adenomatous Polyps / Q000235:genetics / Q000378:metabolism / Q000601:surgery*; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000601:surgery*; D019175:DNA Methylation; D006801:Humans; D044483:Intestinal Polyposis / Q000235:genetics / Q000378:metabolism / Q000601:surgery*; D007417:Intestinal Polyps / Q000235:genetics / Q000378:metabolism / Q000601:surgery*; D000070957:MutL Protein Homolog 1; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C117307:KRAS protein, human; C501486:MLH1 protein, human; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D000070957:MutL Protein Homolog 1; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins
keywords: Hypermethylation; Hyperplastic; Serrated; Serrated polyposis syndrome; Sessile serrated adenoma/polyp