title: Clinicopathological characteristics of serrated polyps as precursors to colorectal cancer: Current status and management.
abstract: Serrated polyps have long been thought to lack malignant potential in the human colorectum. However, identification of the serrated pathway to colorectal cancer based on molecular biology has improved our understanding of the pathogenesis of colorectal cancers. Accordingly, serrated polyps such as traditional serrated adenoma and sessile serrated adenoma/polyps (SSA/P) are now considered to be precursor lesions of the serrated pathway. Recently, serrated polyps were classified into three subtypes, consisting of hyperplastic polyp, SSA/P, and traditional serrated adenoma, according to the World Health Organization classification. It has been suggested that SSA/P in the proximal colon are a precursor lesion of pathogenesis of colorectal cancer and are characterized by BRAF mutation and a CpG island methylator phenotype with or without microsatellite instability. However, SSA/P is more challenging to detect by colonoscopy and is likely to account for some interval cancers, particularly in the proximal colon because it presents flat or sessile, isochroous appearance, and occasionally has a mucous cap. Furthermore, the possibility has been raised that pathologists misclassify SSA/P as hyperplastic polyp. It is important for gastroenterologists to recognize the endoscopic features of serrated polyps to facilitate their detection and removal and also to establish postpolypectomy surveillance guidelines. In this review, we discuss the recent classification of serrated polyps; the molecular characteristics of the serrated pathway; appropriate diagnostic methods using endoscopy, including a new image-enhanced endoscopic technique; and management of these lesions.
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Okamoto
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Kitamura
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kimura
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Tadahiko
authors.initials: T
authors.lastname: Nakagawa
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sogabe
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyamoto
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Muguruma
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Takayama
mesh_terms: D003111:Colonic Polyps / Q000145:classification / Q000150:complications* / Q000175:diagnosis / Q000235:genetics; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000209:etiology* / Q000517:prevention & control; D018899:CpG Islands / Q000235:genetics; D006801:Humans; D053842:Microsatellite Instability; D009154:Mutation; D010641:Phenotype; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf
keywords: DNA methylation; SSA/P; Serrated polyps; colorectal cancer; serrated pathway