title: Meta-analysis: Barrett's oesophagus and the risk of colonic tumours.
abstract: BACKGROUND
  Barrett's oesophagus (BO) is a premalignant condition associated with oesophageal adenocarcinoma. Although speculation exists, it is currently unclear if BO is associated with an increased risk of colonic tumours.
  
  
  OBJECTIVE
  To conduct a meta-analysis of studies reporting the prevalence of colonic tumours in patients with BO vs. controls and thus quantify the risk of colonic tumours associated with BO.
  
  
  METHODS
  A search was conducted through Medline, PubMed, Embase, and Current Contents Connect to 7 October 2012. We calculated pooled odds ratios (OR) and 95% confidence intervals (CI) using a random-effects model for the risk of all colonic tumours associated with BO, as well as for the subgroups of colorectal cancer (CRC) and benign adenomatous tumours.
  
  
  RESULTS
  In total, 11 studies, with 2580 BO cases, met our inclusion criteria. BO was associated with an increased risk of any colonic tumours (OR: 1.96; 95% CI: 1.56-2.46). BO was associated with an increased risk of benign adenomatous tumours (OR: 1.69; 95% CI: 1.20-2.39), as well as an increased risk of CRC (OR: 1.90; 95% CI: 1.35-2.67). No statistically significant heterogeneity was observed. Publication bias was not present.
  
  
  CONCLUSIONS
  Barrett's oesophagus was associated with an increased risk of both benign adenomatous colonic tumours and colorectal cancer. Barrett's oesophagus had a stronger association with colorectal cancer than with benign colonic tumours. Further prospective cohort studies are needed to confirm the relationship.
authors.affiliation: The Whiteley-Martin Research Centre, The Discipline of Surgery, The University of Sydney, Sydney Medical School, Penrith, NSW, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Andrici
authors.forename: M
authors.initials: M
authors.lastname: Tio
authors.forename: M R
authors.initials: MR
authors.lastname: Cox
authors.forename: G D
authors.initials: GD
authors.lastname: Eslick
mesh_terms: D001471:Barrett Esophagus / Q000150:complications*; D003110:Colonic Neoplasms / Q000209:etiology*; D006801:Humans; D012307:Risk Factors