title: [Colonic adenoma: risk factors for their malignant transformation].
abstract: BACKGROUND
  Almost all colorectal cancers develop from adenomatous polyp, its detection and resection prevent the malignization. Several adenoma characteristics like: number, size, morphology, histologic type and grade of dysplasia have become considered as malignization risk factors.
  
  
  OBJECTIVE
  This study was designed to determine the frequency of colorectal adenoma and the principal risk factors for malignization.
  
  
  METHODS
  Between June of 1989 and July of 1994, 846 colonoscopies were performed and retrospectively analyzed in the same number of patients. The patients with colorectal polyps were chosen for the analysis of this study as well all the polyps characteristics, to determine the risk factors for malignization.
  
  
  RESULTS
  There were 183 patients (21.6%) with 322 colorectal polyps. Of all of them, only 214 (66.4%) underwent colonoscopy snare resection and were studied; 120 (57%) were neoplastic polyps and 94 (43%) non neoplastic; among those neoplastic polyps, 100 (83.4%) were tubular adenomas, 11 (9.1%) were tubulovillous adenomas, and 9 (7.5%) were villous adenomas. We found 16 (7.4%) polyps with adenocarcinoma, 14 (87.5%) were found in patients older than 50 years of age and in polyps larger than 1 cm in diameter (p 0.040). Eleven (68.7%) were sessiles (p 0.001).
  
  
  CONCLUSIONS
  After the evaluation of polyps, the tubular adenomas were the neoplastic polyps more frequently found. In this particular study, the patient age, polyp size and morphology were the more statistically significant risk factors for malignization in our patient group.
authors.affiliation: Departamento de Cirugía de Colon y Recto, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, México, D.F. México.
authors.forename: J L
authors.initials: JL
authors.lastname: Rocha Ramírez
authors.forename: J P
authors.initials: JP
authors.lastname: Peña
authors.forename: J R
authors.initials: JR
authors.lastname: Franco Gutiérrez
authors.forename: E
authors.initials: E
authors.lastname: Villanueva Sáenz
mesh_terms: D000236:Adenoma / Q000453:epidemiology / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002471:Cell Transformation, Neoplastic; D003110:Colonic Neoplasms / Q000453:epidemiology / Q000473:pathology*; D003111:Colonic Polyps / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors
vernacular_title: Adenomas colónicos: factores de riesgo para su malignización.