title: Clinical factors associated with non-polypoid colonic adenomas ≥6 mm: a prospective study in an asymptomatic population using a high-definition colonoscope.
abstract: OBJECTIVE
  To examine the clinical factors associated with adenomas ≥6 mm presenting as non-polypoid polyps.
  
  
  METHODS
  We conducted a prospective cross-sectional examination with a target population of consecutive asymptomatic patients presenting to a University endoscopy center for screening colonoscopy. Data, which included demographics, known colorectal cancer risk factors, and medications, were collected. One endoscopist using a high-definition wide-angle colonoscope performed all of the colonoscopies. Polyp morphology was classified according to the JRSC (Japanese Research Society for Cancer of Colon and Rectum) JRSC guidelines.
  
  
  RESULTS
  A total of 600 patients were screened and 150 adenomas ≥6 mm were detected. Of these 150 adenomas, 70 adenomas had a non-polypoid morphology while 80 were polypoid. Adenomas were more likely to present as non-polypoid in women as compared with men (adjusted odds ratio (AOR)=2.49; 95% confidence interval (CI)=1.08-5.75, P=0.03). Location of the adenoma in the proximal colon (AOR=4.21; 95% CI=1.83-9.71, P=0.001) and smoking (AOR=2.54; 95% CI=1.01-6.38, P=0.048) were independent predictors of flat morphology. In addition, advanced adenomas were also more likely to be flat in women (AOR=7.99; 95% CI=1.32-48.39, P=0.02) and proximal location was an independent predictor of flat morphology.
  
  
  CONCLUSIONS
  Adenomas ≥6 mm and advanced lesions were more likely to present as non-polypoid polyps in women when compared with men. Proximal location and smoking were also observed to be independent predictors of flat morphology.
authors.affiliation: Department of Gastroenterology, University of Connecticut Health Center, Farmington, Connecticut 06030-1845, USA.
authors.forename: Maria E
authors.initials: ME
authors.lastname: Johnson
authors.forename: Richard
authors.initials: R
authors.lastname: Feinn
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Anderson
mesh_terms: D000236:Adenoma / Q000473:pathology*; D000368:Aged; D003110:Colonic Neoplasms / Q000473:pathology*; D003111:Colonic Polyps / Q000473:pathology*; D003113:Colonoscopy; D003430:Cross-Sectional Studies; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D012737:Sex Factors; D012907:Smoking