title: Inflammatory bowel disease is associated with an increased risk of melanoma: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Inflammatory bowel disease (IBD) has been associated with an increased risk of nonmelanoma skin cancer, particularly among patients treated with thiopurines. It is unclear whether IBD affects risk for melanoma. We performed a systematic review and meta-analysis of cohort studies to determine the risk of melanoma in patients with IBD.
  
  
  METHODS
  We conducted a systematic search of bibliographic databases through March 2013. Cohort studies reporting incident melanoma after IBD diagnosis and an estimate of incidence rate ratio or standardized incidence rate were included in the analysis. Pooled relative risk (RR) estimates with 95% confidence intervals (CIs) were calculated using the random-effects model.
  
  
  RESULTS
  Our analysis included 12 studies, comprising a total of 172,837 patients with IBD; 179 cases of melanoma were reported from 1940 to 2009. The pooled crude incidence rate of melanoma in patients with IBD was 27.5 cases/100,000 person-years (95% CI, 19.9-37.0). Overall, IBD was associated with a 37% increase in risk of melanoma (12 studies: RR, 1.37; 95% CI, 1.10-1.70). The risk was increased among patients with Crohn's disease (7 studies: RR, 1.80; 95% CI, 1.17-2.75) and ulcerative colitis (7 studies: RR, 1.23; 95% CI, 1.01-1.50). The risk of melanoma was higher in studies performed before introduction of biologic therapies (before 1998) (8 studies: RR, 1.52; 95% CI, 1.02-2.25) but not in studies performed after 1998 (2 studies: RR, 1.08; 95% CI, 0.59-1.96).
  
  
  CONCLUSIONS
  Based on a meta-analysis, IBD has been associated with an increased risk of melanoma, independent of the use of biologic therapy. Patients diagnosed with IBD should be counseled on their risk for melanoma.
authors: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota.
authors: Siddharth
authors: S
authors: Singh
authors: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota.
authors: Sajan Jiv Singh
authors: SJ
authors: Nagpal
authors: Department of Preventive Medicine, Mayo Clinic, Rochester, Minnesota.
authors: Mohammad H
authors: MH
authors: Murad
authors: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota.
authors: Siddhant
authors: S
authors: Yadav
authors: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota.
authors: Sunanda V
authors: SV
authors: Kane
authors: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota.
authors: Darrell S
authors: DS
authors: Pardi
authors: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota.
authors: Jayant A
authors: JA
authors: Talwalkar
authors: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota. Electronic address: loftus.edward@mayo.edu.
authors: Edward V
authors: EV
authors: Loftus
mesh_terms: D015331:Cohort Studies; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000453:epidemiology*; D008545:Melanoma / Q000453:epidemiology*; D016017:Odds Ratio; D012307:Risk Factors; D012878:Skin Neoplasms / Q000453:epidemiology*
keywords: CD; CI; Colitis; Crohn's disease; IBD; IRR; RR; Risk Factors; SIR; Skin Cancer; TNF; Thiopurines; Tumor Necrosis Factor Therapy; UC; confidence interval; incidence rate ratio; inflammatory bowel disease; relative risk; standardized incidence ratio; tumor necrosis factor; ulcerative colitis