title: Colorectal cancer incidence is low in patients following a colonoscopy.
abstract: OBJECTIVE
  Colonoscopy has been proven a valuable tool in preventing colorectal cancer in controlled studies; we conducted a longitudinal confirmation study in everyday clinical practice.
  
  
  METHODS
  In a retrospective study, we monitored the outcome of patients with a total colonoscopy at our hospital between 1994 and 2007. We analysed the data of in-house follow-up colonoscopies, a national person registry and the morphological tumour registry centralizing all histopathological data at a national level. Patients with a particular colorectal cancer risk were excluded.
  
  
  RESULTS
  8950 patients were included in our study. 2032 (22.7%) patients had at least one colorectal adenoma at index colonoscopy. Adenoma prevalence was significantly higher in men than in women (27.9% vs. 17.4%, p<0.001) and was increasing with age in both sexes. Patients were followed for a mean of 5.2 years and 19 had invasive colorectal cancer detected over 47,725 person years of follow-up. The incidence rate was 0.40 cases/1000 person years of follow-up (95% confidence interval, 0.25-0.62), and the standardized incidence ratio was 0.37 (95% confidence interval, 0.24-0.58).
  
  
  CONCLUSIONS
  Incidence rates of colorectal cancer are low in the follow-up of patients having undergone a total colonoscopy in everyday practice. After standard therapy of colorectal adenomas at colonoscopy, there is little evidence for excess colorectal cancer incidence in this subgroup.
authors.affiliation: HepatoGastroenterology, Centre Hospitalier de Luxembourg, Luxembourg. paul.strock@ch-carcassonne.fr
authors.forename: Paul
authors.initials: P
authors.lastname: Strock
authors.forename: Joël
authors.initials: J
authors.lastname: Mossong
authors.forename: René
authors.initials: R
authors.lastname: Scheiden
authors.forename: Jos
authors.initials: J
authors.lastname: Weber
authors.forename: Frank
authors.initials: F
authors.lastname: Heieck
authors.forename: André
authors.initials: A
authors.lastname: Kerschen
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology*; D000236:Adenoma / Q000453:epidemiology* / Q000473:pathology; D000367:Age Factors; D000368:Aged; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008137:Longitudinal Studies; D008189:Luxembourg / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies