title: Clinical impact of surveillance colonoscopy using magnification without diminutive polyp removal.
abstract: OBJECTIVE
  In Western countries, endoscopic removal of all adenomas during colonoscopy is recommended. The present study evaluates the usefulness of magnifying colonoscopy without removal of diminutive (≤5 mm) colorectal polyps.
  
  
  METHODS
  Patients with diminutive polyps who were observed for over 5 years using magnification at Hiroshima University Hospital were selected retrospectively. Lesions ≥6 mm in size, depressed lesions, and lesions with type V pit pattern were indications for endoscopic resection. We investigated the characteristics of lesions indicated for endoscopic resection detected on surveillance colonoscopy and the risk factors for the incidence of lesions indicated for endoscopic resection.
  
  
  RESULTS
  A total of 706 consecutive patients were enrolled. Sixty-eight lesions indicated for endoscopic resection were detected, averaging 9.0 ± 4.8 mm, and 33 (49%) lesions were located in the right colon. Pathological diagnoses were adenoma, Tis carcinoma, and T1 carcinoma in 58 (85%), eight (12%), and two (3%) lesions, respectively. Five lesions were considered to grow from previously detected diminutive polyps. Relative risks for the incidence of a lesion indicated for endoscopic resection were 1.76 (95% confidence interval [CI], 1.004-3.23) for males compared with females, 3.76 (95% CI, 2.03-7.50) for more than three polyps at initial colonoscopy compared with one polyp, and 2.84 (95% CI, 1.43-5.24) for patients with carcinoma at initial colonoscopy compared with patients with no lesion indicated for endoscopic resection. Nine carcinomas were resected endoscopically.
  
  
  CONCLUSIONS
  Diminutive low-grade adenomas detected by using magnifying colonoscopy may not necessarily require removal.
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Yuki
authors.identifier: http://orcid.org/0000-0002-6602-7199
authors.initials: Y
authors.lastname: Ninomiya
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Oka
authors.affiliation: Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Boda
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Yamashita
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kyoku
authors.initials: K
authors.lastname: Sumimoto
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Daiki
authors.initials: D
authors.lastname: Hirano
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Tamaru
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Shigita
authors.affiliation: Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Nana
authors.initials: N
authors.lastname: Hayashi
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Taiji
authors.initials: T
authors.lastname: Matsuo
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Chayama
mesh_terms: D000236:Adenoma / Q000175:diagnosis / Q000601:surgery*; D000328:Adult; D000367:Age Factors; D000368:Aged; D015331:Cohort Studies; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000601:surgery*; D003111:Colonic Polyps / Q000175:diagnosis / Q000601:surgery*; D003113:Colonoscopy / Q000009:adverse effects / Q000379:methods*; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006785:Hospitals, University; D006801:Humans; D007564:Japan; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011858:Radiographic Magnification / Q000379:methods; D012189:Retrospective Studies; D018570:Risk Assessment; D012737:Sex Factors
keywords: colon; colonoscopy; magnification; polyp; surveillance