title: Risk of proximal colon neoplasia with distal hyperplastic polyps: a meta-analysis.
abstract: BACKGROUND
  Most guidelines for colorectal cancer screening do not consider distal hyperplastic polyps (HPs) to be markers for proximal colon neoplasia. However, many studies have shown an increased risk of proximal neoplasia (PN) in patients with distal HPs. We performed a systematic review to assess the association between distal HPs and PN.
  
  
  METHODS
  We identified studies that compared the prevalence of PN and proximal advanced neoplasia in patients with distal HPs vs controls. Two masked investigators extracted data on individuals with distal HPs, distal adenomas, or no distal polyps. Using the DerSimonian and Laird method, we calculated summary risk ratios. Extensive subgroup analysis was performed.
  
  
  RESULTS
  The prevalence of PN and proximal advanced neoplasia in persons with distal HPs was 26.0% and 4.4%, respectively. In studies comparing the risk of PN in patients with distal HPs vs those with no distal polyps, the summary risk ratio was 1.81 (95% confidence interval, 1.20-2.73). However, this increased risk disappeared if only high-quality studies on screening patients were considered. The risk ratio was 0.69 (95% confidence interval, 0.60-0.80) when comparing the risk of PN in those with distal HPs vs those with distal adenomas.
  
  
  CONCLUSIONS
  Overall, patients with distal HPs have an intermediate risk of PN compared with those with distal adenomas or no distal polyps; however, in asymptomatic screening individuals, there is no increased risk of PN or proximal advanced neoplasia. The discovery of HPs on screening flexible sigmoidoscopy should not automatically prompt follow-up colonoscopy.
authors.affiliation: Gastroenterology Section, Virginia Mason Medical Center, Seattle, WA 98101, USA. Otto.Lin@vmmc.org
authors.forename: Otto S
authors.initials: OS
authors.lastname: Lin
authors.forename: Lauren B
authors.initials: LB
authors.lastname: Gerson
authors.forename: Maw-Soan
authors.initials: MS
authors.lastname: Soon
authors.forename: Drew B
authors.initials: DB
authors.lastname: Schembre
authors.forename: Richard A
authors.initials: RA
authors.lastname: Kozarek
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000473:pathology; D000328:Adult; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D003111:Colonic Polyps / Q000175:diagnosis* / Q000473:pathology; D003113:Colonoscopy; D003430:Cross-Sectional Studies; D006801:Humans; D006965:Hyperplasia; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors