title: Clinical features, treatment, and survival of patients with colorectal cancer with or without inflammatory bowel disease.
abstract: OBJECTIVE
  Inflammatory bowel disease (IBD) increases the risk of colorectal cancer (CRC), indicating that inflammation might alter tumor characteristics and potentially affect treatment and survival. Published data on this topic are inconclusive, so we conducted a population-based study in Ireland to address it.
  
  
  METHODS
  We used the National Cancer Registry to collect data on all patients diagnosed with CRC in Ireland from 1994 to 2005 (n = 22,335) and identified those who also had IBD (n = 170). The clinical characteristics, treatment, and survival of patients with IBD and CRC were compared with those of patients with CRC without IBD.
  
  
  RESULTS
  Patients with CRC and IBD were, on average, 7.7 years younger than those without IBD at diagnosis of CRC (P = .001), and were less likely to smoke (P = .002). Fewer CRCs in patients with IBD were stage 4 at diagnosis (12% vs 22% in non-IBD patients; P < .001). There was no significant difference in CRC treatment modalities between patients with or without IBD (P = .57). The median survival time of CRC patients with IBD was about 3 years longer than that of patients without IBD (P < .001). However, Cox proportional hazards analysis revealed that IBD was not a significant prognostic factor for CRC (P = .97). However, older age, male sex, smoking, and advanced grade and stage all were associated independently with shorter survival time. When propensity score matching was used to analyze outcomes, the survival times of CRC patients with and without IBD did not differ significantly.
  
  
  CONCLUSIONS
  The features of patients with CRC and IBD differ significantly from those of CRC patients without IBD, but each group of patients receive similar treatment and have similar patterns of disease progression after diagnosis.
authors.affiliation: Pharmacology and Therapeutics, School of Medicine, National University of Ireland, Galway, Ireland.
authors.forename: Raja Affendi Raja
authors.initials: RA
authors.lastname: Ali
authors.forename: Cara
authors.initials: C
authors.lastname: Dooley
authors.forename: Harry
authors.initials: H
authors.lastname: Comber
authors.forename: John
authors.initials: J
authors.lastname: Newell
authors.forename: Laurence John
authors.initials: LJ
authors.lastname: Egan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000150:complications / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D018450:Disease Progression; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000150:complications / Q000473:pathology; D007494:Ireland; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D016019:Survival Analysis