title: Case-control study supports extension of surveillance interval after colonoscopic polypectomy to at least 5 yr.
abstract: OBJECTIVE
  Colonoscopy with removal of polyps may strongly reduce colorectal cancer (CRC) incidence and mortality. Recommended time intervals to surveillance colonoscopy differ between countries and have recently been extended to 5 yr or longer for the majority of cases in the United States. Whereas previous evidence is mainly based on observations of adenoma recurrence, we aimed to assess risk of CRC occurrence according to time since polypectomy.
  
  
  METHODS
  In a population-based case-control study conducted in Germany, detailed history and results of previous large bowel endoscopies were obtained by interview and from medical records. Risk of CRC among subjects with history of endoscopic polypectomy compared to subjects without previous large bowel endoscopy was assessed according to time since polypectomy among 454 cases with CRC and 391 matched controls.
  
  
  RESULTS
  Odds ratios (95% confidence intervals) of CRC up to 2 yr, 3-5 yr, and 6-10 yr after polypectomy (using subjects without previous endoscopy as reference group) were 0.16 (0.09-0.69), 0.27 (0.08-0.87), and 1.90 (0.67-5.43), respectively. Risk was significantly reduced (odds ratio 0.27, 95% confidence interval 0.10-0.77) within 5 yr even after detection and removal of high-risk polyps (3+ polyps, at least 1 polyp > or =1 cm, at least 1 polyp with villous components). Odds ratios (95% confidence intervals) for the entire 10-yr time interval following polypectomy were 0.50 (0.23-1.12) and 0.36 (0.18-0.76) for patients with recorded high-risk adenomas and other patients, respectively.
  
  
  CONCLUSIONS
  Our study provides empirical support for extension of the surveillance interval after colonoscopic polypectomy to at least 5 yr.
authors: Department of Epidemiology, German Centre for Research on Ageing, Heidelberg, Germany, and Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, Heidelberg, Germany.
authors: Hermann
authors: H
authors: Brenner
authors: Jenny
authors: J
authors: Chang-Claude
authors: Christoph M
authors: CM
authors: Seiler
authors: Til
authors: T
authors: Stürmer
authors: Michael
authors: M
authors: Hoffmeister
mesh_terms: D000236:Adenoma / Q000175:diagnosis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003110:Colonic Neoplasms / Q000175:diagnosis*; D003111:Colonic Polyps / Q000601:surgery*; D003113:Colonoscopy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D017410:Practice Guidelines as Topic; D013997:Time Factors