title: Small early tubular adenomas and mixed colonic polyps found on screening flexible sigmoidoscopy do not predict proximal neoplasia in males.
abstract: OBJECTIVE
  Distal colonic adenomas found on flexible sigmoidoscopy are associated with proximal neoplasias, thus requiring a complete colonoscopic examination, but data regarding the association of distal mixed polyps with proximal neoplasia are lacking. We conducted this study to elucidate the significance of distal mixed colonic polyps in predicting proximal neoplasia.
  
  
  METHODS
  We retrospectively analyzed data from patients who underwent a flexible sigmoidoscopic examination for colorectal cancer screening and a follow-up colonoscopic examination because of distal colonic polyps. Distal index polyps were classified by a pathologist as early tubular adenoma (ETA), serrated, or true mixed categories. Index polyps also were immunostained with a monoclonal antibody, Adnab-9, a marker for the colorectal adenoma carcinoma sequence.
  
  
  RESULTS
  In 636 patients with distal index polyps, 6% were malignant, 55% were adenomas, 13% were ETAs, 6% were serrated, 4% were true mixed, and 17% were hyperplastic. Compared with distal hyperplastic index polyps, distal malignant polyps (P = 0.0006) and adenomas (P = 0.001) were associated with a significantly increased number of synchronous proximal neoplasia, but the small distal mixed, serrated, or ETA did not predict the increased incidence of proximal neoplasia. Large distal polyps of each category were significantly associated with an increased number of synchronous proximal neoplasias. In support of these findings, immunostaining of distal polyps with Adnab-9 showed predictability for proximal neoplasia only in the adenoma category (P < 0.05).
  
  
  CONCLUSIONS
  Small ETAs, serrated, or mixed polyps found on flexible sigmoidoscopic examination do not increase the probability of synchronous proximal neoplasia.
authors.affiliation: Wayne State University School of Medicine, Detroit, Michigan, USA.
authors.forename: Nadeem
authors.initials: N
authors.lastname: Ullah
authors.forename: Kashif
authors.initials: K
authors.lastname: Qureshi
authors.forename: James
authors.initials: J
authors.lastname: Hatfield
authors.forename: Paula
authors.initials: P
authors.lastname: Sochacki
authors.forename: Doina
authors.initials: D
authors.lastname: David
authors.forename: Hassan
authors.initials: H
authors.lastname: Albataineh
authors.forename: Luis
authors.initials: L
authors.lastname: Mejia
authors.forename: Chaya
authors.initials: C
authors.lastname: Kenkre
authors.forename: Michael
authors.initials: M
authors.lastname: Lawson
authors.forename: Martin
authors.initials: M
authors.lastname: Tobi
mesh_terms: D018256:Adenomatous Polyps / Q000453:epidemiology / Q000473:pathology*; D000368:Aged; D001707:Biopsy, Needle; D015331:Cohort Studies; D003110:Colonic Neoplasms / Q000453:epidemiology / Q000473:pathology*; D003111:Colonic Polyps / Q000453:epidemiology / Q000473:pathology*; D016001:Confidence Intervals; D005260:Female; D005336:Fiber Optic Technology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009367:Neoplasm Staging; D016017:Odds Ratio; D011230:Precancerous Conditions / Q000473:pathology*; D011237:Predictive Value of Tests; D011336:Probability; D018570:Risk Assessment; D017678:Sex Distribution; D020694:Sigmoidoscopes; D012812:Sigmoidoscopy / Q000379:methods