title: Grading of distal colorectal adenomas as predictors for proximal colonic neoplasia and choice of endoscope in population screening: experience from the Norwegian Colorectal Cancer Prevention study (NORCCAP).
abstract: OBJECTIVE
  The purpose of this study was to evaluate the utility of easily measured clinical variables at flexible sigmoidoscopy (FS) screening that might predict a proximal advanced neoplasm (PAN).
  
  
  METHODS
  We studied 1833 subjects with biopsy verified adenomas at FS who subsequently underwent full colonoscopy.
  
  
  RESULTS
  A total of 387 (21%) subjects had proximal colonic neoplasms (PCN) and 85 (5%) had PAN. In univariate comparison, the risk of PAN increased more than threefold in the presence of a distal adenoma measuring either > or =10 mm in diameter or containing villous components. Multiplicity of distal adenomas, severe dysplasia, or age > or =60 years increased the risk of PAN more than twofold. In the multivariate model, the presence of a distal adenoma > or =10 mm, villousness, and multiplicity maintained their significance as predictive variables for increased risk of proximal neoplasms, whereas sex and severe dysplasia lost their significance. By recommending colonoscopy only to individuals with multiple (>1) adenomas or any high risk adenoma at FS, we would have reduced the number of colonoscopies by 1209 (66%) but would have missed 32 (38%) participants with PAN and 217 (56%) with PCN. By using a 60 cm endoscope instead of an ordinary colonoscope at FS, nine (2%) participants with advanced neoplasms, including three patients with cancer, would have been missed.
  
  
  CONCLUSIONS
  The present study supports the concept of defining "any adenoma" as a positive FS, qualifying for colonoscopy. We recommend the use of an ordinary colonoscope instead of a 60 cm sigmoidoscope for FS screening examinations.
authors.affiliation: The Cancer Registry of Norway, Institute of Population-based Cancer Research, Montebello, Oslo, Norway.
authors.forename: G
authors.initials: G
authors.lastname: Gondal
authors.forename: T
authors.initials: T
authors.lastname: Grotmol
authors.forename: B
authors.initials: B
authors.lastname: Hofstad
authors.forename: M
authors.initials: M
authors.lastname: Bretthauer
authors.forename: T J
authors.initials: TJ
authors.lastname: Eide
authors.forename: G
authors.initials: G
authors.lastname: Hoff
mesh_terms: D000236:Adenoma / Q000473:pathology*; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D020776:Endoscopes, Gastrointestinal; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000295:instrumentation / Q000379:methods*; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D012017:Referral and Consultation; D018570:Risk Assessment; D012307:Risk Factors; D012812:Sigmoidoscopy / Q000379:methods*