title: One-year risk for advanced colorectal neoplasia: U.S. versus U.K. risk-stratification guidelines.
abstract: BACKGROUND
  Guidelines from the United Kingdom and the United States on risk stratification after polypectomy differ, as do recommended surveillance intervals.
  
  
  OBJECTIVE
  To compare risk for advanced colorectal neoplasia at 1-year colonoscopy among patients cross-classified by U.S. and U.K. surveillance guidelines.
  
  
  METHODS
  Pooled analysis of 4 prospective studies between 1984 and 1998.
  
  
  METHODS
  Academic and private clinics in the United States.
  
  
  METHODS
  3226 postpolypectomy patients with 6- to 18-month follow-up colonoscopy.
  
  
  METHODS
  Rates of advanced neoplasia (an adenoma ≥1 cm, high-grade dysplasia, >25% villous architecture, or invasive cancer) at 1 year, compared across U.S. and U.K. risk categories.
  
  
  RESULTS
  Advanced neoplasia was detected 1 year after polypectomy in 3.8% (95% CI, 2.7% to 4.9%) of lower-risk patients and 11.2% (CI, 9.8% to 12.6%) of higher-risk patients by U.S. criteria. According to U.K. criteria, 4.4% (CI, 3.3% to 5.4%) of low-risk patients, 9.9% (CI, 8.3% to 11.5%) of intermediate-risk patients, and 18.7% (CI, 14.8% to 22.5%) of high-risk patients presented with advanced neoplasia; U.K. high-risk patients comprised 12.1% of all patients. All U.S. lower-risk patients were low-risk by U.K. criteria; however, more patients were classified as low-risk, because the U.K. guidelines do not consider histologic features. Higher-risk U.S. patients were distributed across the 3 U.K. categories. Among all patients with advanced neoplasia, 26.3% were reclassified by the U.K. criteria to a higher-risk category and 7.0% to a lower-risk category, with a net 19.0% benefiting from detection 2 years earlier. Overall, substitution of U.K. for U.S. guidelines resulted in an estimated 0.03 additional colonoscopy every 5 years per patient.
  
  
  CONCLUSIONS
  Patients were enrolled 15 to 20 years ago, and quality measures for colonoscopy were unavailable. Patients lacking follow-up colonoscopy or with surveillance colonoscopy after 6 to 18 months and those with cancer or insufficient baseline adenoma characteristics were excluded (2076 of 5302).
  
  
  CONCLUSIONS
  Application of the U.K. guidelines in the United States could identify a subset of high-risk patients who may warrant a 1-year clearing colonoscopy without substantially increasing rates of colonoscopy.
  
  
  BACKGROUND
  European Union Public Health Programme.
authors.affiliation: Moores Cancer Center, University of California, San Diego, 3855 Health Sciences Drive 0901, La Jolla, CA 92093-0901, USA. e8martinez@ucsd.edu
authors.forename: María Elena
authors.initials: ME
authors.lastname: Martínez
authors.forename: Patricia
authors.initials: P
authors.lastname: Thompson
authors.forename: Karen
authors.initials: K
authors.lastname: Messer
authors.forename: Erin L
authors.initials: EL
authors.lastname: Ashbeck
authors.forename: David A
authors.initials: DA
authors.lastname: Lieberman
authors.forename: John A
authors.initials: JA
authors.lastname: Baron
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Ahnen
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Robertson
authors.forename: Elizabeth T
authors.initials: ET
authors.lastname: Jacobs
authors.forename: E Robert
authors.initials: ER
authors.lastname: Greenberg
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Cross
authors.forename: Wendy
authors.initials: W
authors.lastname: Atkin
mesh_terms: D000236:Adenoma / Q000453:epidemiology* / Q000473:pathology; D018253:Adenoma, Villous / Q000453:epidemiology / Q000473:pathology; D003111:Colonic Polyps / Q000601:surgery*; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000473:pathology; D006801:Humans; D017410:Practice Guidelines as Topic / Q000592:standards*; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors; D006113:United Kingdom; D014481:United States / Q000453:epidemiology