title: Risk of adenomas with high-risk characteristics based on two previous colonoscopy.
abstract: OBJECTIVE
  The recommended intervals between surveillance colonoscopies are based on the most recent examination findings. However, whether the two previous colonoscopies affect second surveillance colonoscopic findings is not established. The aim of this study is to estimate the risk of obtaining high-risk findings (HRF) on the next surveillance colonoscopy using the results of two previous colonoscopies, and to estimate the appropriate time interval for the next surveillance colonoscopy.
  
  
  METHODS
  Among subjects who underwent screening colonoscopy during January 2002-December 2009, patients who underwent second surveillance colonoscopy before June 2012 were enrolled. "No adenoma" was defined as a hyperplastic polyp or no polyp, "low-risk findings (LRF)" as one or two small (< 1 cm) tubular adenomas, and "HRF" as advanced adenoma, cancer, or any sized multiple (≥ 3) adenomas.
  
  
  RESULTS
  Among enrolled 852 subjects, 65 (7.6%) had HRF at second surveillance colonoscopy. Multivariate analysis showed that HRF on second surveillance colonoscopy were associated with male and HRF on screening colonoscopy (all, P < 0.01). In subjects with LRF on first surveillance colonoscopy, HRF on the screening colonoscopy significantly affected the detection of HRF on second surveillance colonoscopy (P < 0.01). Patients with HRF on screening colonoscopy and LRF on the first surveillance colonoscopy had no different risk of HRF on second surveillance colonoscopy from those with HRF on first surveillance colonoscopy (P > 0.05).
  
  
  CONCLUSIONS
  The HRF on second surveillance are significantly associated with previous two colonoscopic results. In patients with LRF on first surveillance, screening colonoscopic findings should be considered to determine the optimal surveillance interval.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Kang-Heum
authors.initials: KH
authors.lastname: Suh
authors.forename: Ja Seol
authors.initials: JS
authors.lastname: Koo
authors.forename: Jong Jin
authors.initials: JJ
authors.lastname: Hyun
authors.forename: Jungsoon
authors.initials: J
authors.lastname: Choi
authors.forename: Jang Soo
authors.initials: JS
authors.lastname: Han
authors.forename: Seung Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Sung Woo
authors.initials: SW
authors.lastname: Jung
authors.forename: Yoon Tae
authors.initials: YT
authors.lastname: Jeen
authors.forename: Sang Woo
authors.initials: SW
authors.lastname: Lee
authors.forename: Jai Hyun
authors.initials: JH
authors.lastname: Choi
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000517:prevention & control*; D000328:Adult; D000368:Aged; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000517:prevention & control*; D003113:Colonoscopy; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012306:Risk
keywords: high-risk findings; polypectomy; surveillance colonoscopy