title: A pooled analysis of advanced colorectal neoplasia diagnoses after colonoscopic polypectomy.
abstract: OBJECTIVE
  Limited data exist regarding the actual risk of developing advanced adenomas and cancer after polypectomy or the factors that determine risk.
  
  
  METHODS
  We pooled individual data from 8 prospective studies comprising 9167 men and women aged 22 to 80 with previously resected colorectal adenomas to quantify their risk of developing subsequent advanced adenoma or cancer as well as identify factors associated with the development of advanced colorectal neoplasms during surveillance.
  
  
  RESULTS
  During a median follow-up period of 47.2 months, advanced colorectal neoplasia was diagnosed in 1082 (11.8%) of the patients, 58 of whom (0.6%) had invasive cancer. Risk of a metachronous advanced adenoma was higher among patients with 5 or more baseline adenomas (24.1%; standard error, 2.2) and those with an adenoma 20 mm in size or greater (19.3%; standard error, 1.5). Risk factor patterns were similar for advanced adenomas and invasive cancer. In multivariate analyses, older age (P < .0001 for trend) and male sex (odds ratio [OR], 1.40; 95% confidence interval [CI], 1.19-1.65) were associated significantly with an increased risk for metachronous advanced neoplasia, as were the number and size of prior adenomas (P < .0001 for trend), the presence of villous features (OR, 1.28; 95% CI, 1.07-1.52), and proximal location (OR, 1.68; 95% CI, 1.43-1.98). High-grade dysplasia was not associated independently with metachronous advanced neoplasia after adjustment for other adenoma characteristics.
  
  
  CONCLUSIONS
  Occurrence of advanced colorectal neoplasia is common after polypectomy. Factors that are associated most strongly with risk of advanced neoplasia are patient age and the number and size of prior adenomas.
authors.affiliation: Arizona Cancer Center, University of Arizona, Tucson, Arizona, USA.
authors.forename: María Elena
authors.initials: ME
authors.lastname: Martínez
authors.forename: John A
authors.initials: JA
authors.lastname: Baron
authors.forename: David A
authors.initials: DA
authors.lastname: Lieberman
authors.forename: Arthur
authors.initials: A
authors.lastname: Schatzkin
authors.forename: Elaine
authors.initials: E
authors.lastname: Lanza
authors.forename: Sidney J
authors.initials: SJ
authors.lastname: Winawer
authors.forename: Ann G
authors.initials: AG
authors.lastname: Zauber
authors.forename: Ruiyun
authors.initials: R
authors.lastname: Jiang
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Ahnen
authors.forename: John H
authors.initials: JH
authors.lastname: Bond
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Church
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Robertson
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Smith-Warner
authors.forename: Elizabeth T
authors.initials: ET
authors.lastname: Jacobs
authors.forename: David S
authors.initials: DS
authors.lastname: Alberts
authors.forename: E Robert
authors.initials: ER
authors.lastname: Greenberg
mesh_terms: D000236:Adenoma / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D003111:Colonic Polyps / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D017678:Sex Distribution; D055815:Young Adult