title: Prevalence and molecular characterisation of the sessile serrated adenoma in a subset of the Chinese population.
abstract: OBJECTIVE
  The incidence and mortality rates from right-sided colorectal cancers (CRCs) have not decreased in recent years. It is very likely that a significant proportion of these cancers evolve from undetected sessile serrated adenomas (SSAs). The prevalence and molecular features of the SSAs in the Chinese population have seldom been investigated.
  
  
  METHODS
  We retrospectively reviewed the colonoscopy database and pathology archives in our medical centre. Adenomatous polyposis coli (APC) and β-catenin expressions were examined in 28 right hyperplastic polyps (RHPs) and 21 SSAs by immunohistochemical staining. The mutations of BRAF, KRAS, APC and β-CATENIN were analysed by direct sequencing. The methylation status of APC promoter in these polyps was analysed by methylation-specific PCR and bisulfite sequencing. Samples of left hyperplastic polyps, traditional adenomas and CRC were used as controls.
  
  
  RESULTS
  SSAs accounted for 4.9% of serrated polyps and 1.0% of all colorectal polyps. BRAF((V600E)) mutations were found in 14.3% of SSAs and 7.1% of RHPs. Nuclear accumulation of β-catenin was seen in 28.6% of SSAs and 17.9% of RHPs. APC mutations were detected in 57.1% of SSAs and 67.9% of RHPs. APC methylation was detected in 14.3% of RHPs and 23.8% of SSAs.
  
  
  CONCLUSIONS
  The prevalence of SSAs in a subset of the Chinese population is much lower than that in the Western population. BRAF((V600E)) mutation is not a frequent event in right colon serrated polyps in a subset of the Chinese population. APC mutation is possibly the main cause for the Wnt signalling activation in right colon serrated polyps.
authors.affiliation: Department of Gastroenterology, The Affiliated Hospital of Luzhou Medical College, Sichuan, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Qiu
authors.affiliation: Department of Gastroenterology, The Affiliated Hospital of Luzhou Medical College, Sichuan, China.
authors.forename: Xiangsheng
authors.initials: X
authors.lastname: Fu
authors.affiliation: Department of Gastroenterology, The Affiliated Hospital of Luzhou Medical College, Sichuan, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Endocrinology, The Affiliated Hospital of Luzhou Medical College, Sichuan, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Gastroenterology, The Affiliated Hospital of Luzhou Medical College, Sichuan, China.
authors.forename: Lanyue
authors.initials: L
authors.lastname: Xiao
authors.affiliation: Department of Gastroenterology, The Affiliated Hospital of Luzhou Medical College, Sichuan, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Gastroenterology, The Affiliated Hospital of Luzhou Medical College, Sichuan, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
authors.affiliation: Department of Gastroenterology, The Affiliated Hospital of Luzhou Medical College, Sichuan, China.
authors.forename: Xian
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Gastroenterology, The Affiliated Hospital of Luzhou Medical College, Sichuan, China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Xia
authors.affiliation: Department of Gastroenterology, The Affiliated Hospital of Luzhou Medical College, Sichuan, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Peng
authors.affiliation: Department of Gastroenterology, The Affiliated Hospital of Luzhou Medical College, Sichuan, China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Deng
mesh_terms: D000236:Adenoma / Q000737:chemistry / Q000145:classification / Q000208:ethnology* / Q000235:genetics* / Q000473:pathology; D025601:Adenomatous Polyposis Coli Protein / Q000032:analysis / Q000235:genetics; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000235:genetics*; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics*; D001706:Biopsy; D002681:China / Q000453:epidemiology; D003111:Colonic Polyps / Q000737:chemistry / Q000145:classification / Q000208:ethnology* / Q000235:genetics* / Q000473:pathology; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000145:classification / Q000208:ethnology* / Q000235:genetics* / Q000473:pathology; D019175:DNA Methylation; D004252:DNA Mutational Analysis; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D011237:Predictive Value of Tests; D015995:Prevalence; 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); D012189:Retrospective Studies; D051176:beta Catenin / Q000032:analysis / Q000235:genetics; D018631:ras Proteins / Q000235:genetics
chemical_list: C555337:APC protein, human; D025601:Adenomatous Polyposis Coli Protein; D014408:Biomarkers, Tumor; C495270:CTNNB1 protein, human; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D051176:beta Catenin; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins
keywords: CANCER RESEARCH; COLON; COLORECTAL CANCER