title: A meta-analysis of the clinicopathological characteristics and survival outcomes of inflammatory bowel disease associated colorectal cancer.
abstract: OBJECTIVE
  The current study aims to use meta-analytical techniques to compare the clinicopathological characteristics and survival outcomes of inflammatory bowel disease (IBD) associated and sporadic colorectal carcinoma (CRC). Patients with IBD have an established increased risk of developing CRC. There is no consensus, however, on the clinicopathological characteristics and survival outcomes of IBD associated CRC when compared to sporadic CRC.
  
  
  METHODS
  A comprehensive search for published studies comparing IBD associated and sporadic CRC was performed. Random effect methods were used to combine data. This study adhered to the recommendations of the MOOSE guidelines.
  
  
  RESULTS
  Data were retrieved from 20 studies describing 571,278 patients. IBD associated CRC had an increased rate of synchronous tumors (OR 4.403, 95% CI 2.320-8.359; p < 0.001), poor differentiation (OR 1.875, 95% CI 1.425-2.466; p < 0.001), and a reduced rate of rectal cancer (OR 0.827, 95% CI 0.735-0.930; p = 0.002). IBD associated CRC however did not affect the frequency of T3/T4 tumors (OR 0.931, 95% CI 0.782-1.108; p = 0.421), lymph node positivity (OR 1.061, 95% CI 0.929-1.213; p = 0.381), metastasis at presentation (OR 0.970, 95% CI 0.776-1.211; p = 0.786), sex distribution (OR 0.978, 95% CI 0.890-1.074; p = 0.640), or 5-year overall survival (OR 1.105, 95% CI 0.414-2.949; p = 0.842).
  
  
  CONCLUSIONS
  In this large analysis of available data, IBD associated CRC was characterized by less rectal tumors and more synchronous and poorly differentiated tumors compared with sporadic cancers, but no discernable difference in sex distribution, stage at presentation, or survival could be identified.
authors.affiliation: Department of Colorectal Surgery, Beaumont Hospital, Dublin 9, Ireland.
authors.forename: Ian S
authors.initials: IS
authors.lastname: Reynolds
authors.affiliation: Department of Gastroenterology, Beaumont Hospital, Dublin 9, Ireland.
authors.forename: Aobhlinn
authors.initials: A
authors.lastname: O'Toole
authors.affiliation: Department of Colorectal Surgery, Beaumont Hospital, Dublin 9, Ireland.
authors.forename: Joseph
authors.initials: J
authors.lastname: Deasy
authors.affiliation: Department of Colorectal Surgery, Beaumont Hospital, Dublin 9, Ireland.
authors.forename: Deborah A
authors.initials: DA
authors.lastname: McNamara
authors.affiliation: Department of Colorectal Surgery, Beaumont Hospital, Dublin 9, Ireland. johnburke@rcsi.ie.|Royal College of Surgeons, Dublin 2, Ireland. johnburke@rcsi.ie.
authors.forename: John P
authors.initials: JP
authors.lastname: Burke
mesh_terms: D015179:Colorectal Neoplasms / Q000150:complications* / Q000473:pathology*; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000150:complications* / Q000473:pathology*; D008297:Male; D017594:Publication Bias; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome
keywords: Clinicopathological characteristics; Colorectal cancer; Inflammatory bowel disease; Survival outcomes