title: 5-Aminosalicylic acid therapy and the risk of colorectal cancer among patients with inflammatory bowel disease.
abstract: BACKGROUND
  Patients with inflammatory bowel disease (IBD) affecting the colon are at increased risk of developing colorectal cancer (CRC). Published data are conflicting about whether 5-aminosalicylic acid (5-ASA) has chemopreventive properties against IBD-related carcinogenesis. The objective of this observational study was to determine if an association between 5-ASA therapy and CRC risk exists in IBD patients.
  
  
  METHODS
  Adult patients with a new CRC diagnosis (n = 18,440) were identified from 2 large administrative claims databases. For each case, 20 control patients with no record of CRC diagnosis or bowel surgery (n = 368,800) were identified.
  
  
  RESULTS
  An IBD diagnosis was associated with a 6- to 7-fold increased risk of CRC (ulcerative colitis, crude odds ratio [OR] = 6.72, 95% CI, 5.79-7.81; Crohn's disease, crude OR = 6.60, 95% CI, 5.56-7.82). Among patients with IBD (364 CRC cases, 1172 controls), exposure to 5-ASA therapy of any dose or duration during the 12 months before CRC diagnosis was not associated with a reduced risk of CRC (OR = 0.97; 95% CI, 0.77-1.23). However, there was a trend toward a decreased risk of CRC with increasing number of mesalamine prescriptions in the previous year, though statistical significance was not achieved (trend P = 0.08).
  
  
  CONCLUSIONS
  Treating IBD patients with 5-ASA medications was not found to have a protective effect against colitis-related CRC when assessed over a short period of exposure.
authors.affiliation: University of California, San Francisco, San Francisco, California 94143-1623, USA. Jonathan.Terdiman@ucsf.edu
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Terdiman
authors.forename: Michael
authors.initials: M
authors.lastname: Steinbuch
authors.forename: William A
authors.initials: WA
authors.lastname: Blumentals
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Ullman
authors.forename: David T
authors.initials: DT
authors.lastname: Rubin
mesh_terms: D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000627:therapeutic use*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000150:complications / Q000188:drug therapy*; D008297:Male; D019804:Mesalamine / Q000008:administration & dosage / Q000627:therapeutic use*; D012306:Risk; D012460:Sulfasalazine / Q000008:administration & dosage / Q000627:therapeutic use*; D014481:United States / Q000453:epidemiology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D012460:Sulfasalazine; D019804:Mesalamine