Biologics for Inflammatory Bowel Disease Increase Risk for Melanoma

Recent studies have linked use of thiopurines for inflammatory bowel disease (IBD) with an increased risk for nonmelanoma skin cancers (JW Dermatol Feb 17 2012). Now, researchers have utilized an insurance database in the U.S. to retrospectively assess the risk for melanoma and nonmelanoma skin cancer (NMSC) in 108,579 patients with IBD (about half with Crohn disease and half with ulcerative colitis [UC]) compared with control patients without IBD.

Patients with IBD had a higher incidence of melanoma than controls; this association was significant in patients with Crohn disease (incidence rate ratio, 1.45) but not in patients with UC (IRR, 1.13). Researchers observed a trend of increasing risk for melanoma in patients with IBD over time. In a nested case-control analysis, any use of a biologic anti–tumor necrosis factor (anti-TNF) agent was associated with an almost twofold increased risk for melanoma, unlike thiopurines or 5-aminosalicylic acid (5-ASA) medications, for which no associations were observed. The risk for NMSC was increased by almost twofold in patients who used any thiopurine, but was not significantly increased in patients who used anti-TNF agents.