title: Yield of a second screening colonoscopy 10 years after an initial negative examination in average-risk individuals.
abstract: OBJECTIVE
  Current guidelines recommend screening colonoscopy at 10-year intervals in average-risk individuals who had baseline screening colonoscopy (no polyps or only hyperplastic polyps ≤5 mm in the recto-sigmoid colon), but the yield of repeat screening at 10 years is unknown. Our aim was to describe the yield of second screening colonoscopy in average-risk individuals performed at least 8 years after a first screening colonoscopy had shown no polyps or only distal hyperplastic polyps ≤5 mm in size.
  
  
  METHODS
  This was a review of a database for colonoscopies performed at Indiana University Hospital between January 1999 and November 2015.
  
  
  RESULTS
  A total of 4463 individuals underwent screening colonoscopy between January 1999 and July 2007, of which 1566 individuals had no polyps, and 334 individuals had only distal hyperplastic polyps ≤5 mm; 378 individuals (58.4% female) had follow-up screening at least 8 years after the baseline screening examination, with a mean (± standard deviation [SD]) interval of 9.74 years (± 1.2 years; range 8-15 years). Mean (± SD) age at baseline screening examination was 56.7 years (± 5.5 years) and at follow-up screening examination was 66.4 years (± 5.6 years). At the second screening, there were 224 patients (59.3%) with at least 1 polyp, including 144 (38.1%) with at least 1 conventional adenoma. The adenoma detection rate at the second screening examination was 36.1% and 56.8% in the groups with no polyp at baseline and with only distal hyperplastic polyps, respectively. There were 15 advanced neoplasms in 13 individuals (3.4%), of which 12 lesions were proximal to the sigmoid colon. There were no cancers at follow-up.
  
  
  CONCLUSIONS
  Among individuals aged ≥50 years, with normal baseline screening colonoscopy results, the incidence of advanced lesions at a second screening colonoscopy at least 8 years later was comparable to that in baseline screening studies. Our findings support current recommendations for screening at 10-year intervals in average-risk individuals.
authors.affiliation: Division of Gastroenterology and Hepatology, Indiana University School of Medicine, Indianapolis, Indiana, USA.
authors.forename: Prasanna L
authors.initials: PL
authors.lastname: Ponugoti
authors.affiliation: Division of Gastroenterology and Hepatology, Indiana University School of Medicine, Indianapolis, Indiana, USA.
authors.forename: Douglas K
authors.initials: DK
authors.lastname: Rex
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging*; D000368:Aged; D000369:Aged, 80 and over; D003106:Colon / Q000473:pathology*; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging*; D003111:Colonic Polyps / Q000000981:diagnostic imaging* / Q000473:pathology; D003113:Colonoscopy; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013997:Time Factors