title: Conventional colon adenomas harbor various disturbances in microsatellite stability and contain micro-serrated foci with microsatellite instability.
abstract: BACKGROUND
  Colorectal cancer belongs to the most frequent occurring malignancies. A prediction of the clinical outcome and appropriate choice of neoadjuvant chemotherapy needs personalized insight to the main driving pathways. Because most CRCs have polyps as progenitor lesions, studying the pathways driving to adenomagenesis is no less important.
  
  
  OBJECTIVE
  Our purpose was the evaluation of microsatellite stability status within conventional colon adenomas and also β-catenin, BRAFV600E and p53 contribution.
  
  
  METHODS
  The cohort included 101 cases of typical colon adenomas with high grade epithelial dysplasia according to WHO. An immunohistochemistry method was used for the depiction of the expression of targeted proteins, as also their heterogeneity.
  
  
  RESULTS
  Generally, we noted a 10% frequency of MSI events where MSI-H reached a 5% share occurred within the left colon and rectal polyps. β-catenin nuclear overexpression was noted with a 70% frequency and p53 with close to a 24% frequency. In addition, we found a presence of micro-serration foci more often within tubular adenomas, where focal MSI took place more often. Our results indicate that MSI events occur more often than had been theorized earlier. It results in tumour heterogeneity, more complex underlying pathways and finally ontogenetic molecular-diversity of tumours besides similar occurring histopathological features.
authors.affiliation: Department of Pathology, Faculty of Medicine and Health Sciences, Jan Kochanowski University, Kielce, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Lewitowicz
authors.affiliation: Department of Surgery and Surgical Nursing, Faculty of Medicine and Health Sciences, Jan Kochanowski University, Kielce, Poland.
authors.forename: Stanislaw
authors.initials: S
authors.lastname: Gluszek
authors.affiliation: Department of Surgery and Surgical Nursing, Faculty of Medicine and Health Sciences, Jan Kochanowski University, Kielce, Poland.
authors.forename: Dorota
authors.identifier: http://orcid.org/0000-0001-8114-1814
authors.initials: D
authors.lastname: Koziel
authors.affiliation: Department of Public Health, Faculty of Medicine and Health Sciences, Jan Kochanowski University, Kielce, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Horecka-Lewitowicz
authors.affiliation: Department of Probability Theory and Statistics, Institute of Mathematics, The Faculty of Mathematics and Natural Sciences, Jan Kochanowski University, Kielce, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Chrapek
authors.affiliation: Department of Anatomy, Faculty of Medicine and Health Sciences, Jan Kochanowski University, Kielce, Poland.
authors.forename: Przemyslaw
authors.initials: P
authors.lastname: Wolak
authors.affiliation: Department of Surgery and Surgical Nursing, Faculty of Medicine and Health Sciences, Jan Kochanowski University, Kielce, Poland.
authors.forename: Justyna
authors.initials: J
authors.lastname: Klusek
authors.affiliation: Department of Pathology, Faculty of Medicine and Health Sciences, Jan Kochanowski University, Kielce, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Nasierowska-Guttmejer
mesh_terms: D000236:Adenoma / Q000235:genetics* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003111:Colonic Polyps / Q000235:genetics / Q000473:pathology; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D019175:DNA Methylation / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D009154:Mutation; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*; D051176:beta Catenin / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D051176:beta Catenin; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf