title: Effect of Medications on Risk of Cancer in Patients With Inflammatory Bowel Diseases: A Population-Based Cohort Study from Olmsted County, Minnesota.
abstract: OBJECTIVE
  To estimate the overall risk of cancer in a population-based cohort of patients with inflammatory bowel disease (IBD) and how IBD-related medications modify this risk.
  
  
  METHODS
  We identified all incident cancers (excluding nonmelanoma skin cancer) after IBD diagnosis in a cohort of 839 patients diagnosed as having IBD from January 1, 1940, through December 31, 2004, in Olmsted County, Minnesota, and followed up for a median 18 years through December 31, 2011 (122 patients taking biologic agents at last follow-up). We calculated standardized incidence ratios (SIRs) with 95% CIs of all cancers and compared cancer risk in patients treated with immunomodulators (IMMs) and biologics with that of patients not exposed to these medications, using an incidence rate ratio (IRR).
  
  
  RESULTS
  One hundred nine patients developed 135 cancers. The 10-year cumulative probability of cancer was 3.8%. Patients with Crohn disease (SIR, 1.6; 95% CI, 1.2-2.1) but not ulcerative colitis (SIR, 1.1; 95% CI, 0.8-1.4) had an increased overall risk of cancer compared with the general population. Patients treated with IMMs (relative to IMM-naive patients) had an increased risk of melanoma (IRR, 5.3; 95% CI, 1.1-24.8) (and a numerically higher risk of hematologic malignant tumors [IRR, 4.2; 95% CI, 0.9-19.2]), although this risk returned to baseline on discontinuation of IMM treatment. Patients treated with biologics (relative to biologic-naive patients) had a numerically higher risk of hematologic malignant tumors (IRR, 5.3; 95% CI, 0.7-40.5). There was no significant increase in the risk of gastrointestinal malignancies in patients with IBD compared with the general population.
  
  
  CONCLUSIONS
  We observed an increased risk of melanoma in IMM-treated patients with IBD, and this risk returned to baseline after discontinued use of the medications.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Siddhant
authors.initials: S
authors.lastname: Yadav
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Siddharth
authors.initials: S
authors.lastname: Singh
authors.affiliation: Division of Biomedical Statistics & Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN.
authors.forename: W Scott
authors.initials: WS
authors.lastname: Harmsen
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Jithinraj
authors.initials: J
authors.lastname: Edakkanambeth Varayil
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Mayo Clinic, Rochester, MN.
authors.forename: William J
authors.initials: WJ
authors.lastname: Tremaine
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Mayo Clinic, Rochester, MN. Electronic address: loftus.edward@mayo.edu.
authors.forename: Edward V
authors.initials: EV
authors.lastname: Loftus
mesh_terms: D000328:Adult; D000636:Aminosalicylic Acids / Q000627:therapeutic use; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000150:complications / Q000188:drug therapy* / Q000473:pathology; D003424:Crohn Disease / Q000150:complications / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D009369:Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D012306:Risk; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D000636:Aminosalicylic Acids; D005938:Glucocorticoids; D007155:Immunologic Factors; D014409:Tumor Necrosis Factor-alpha