IBD Linked to Increased Risk of Melanoma

Past studies have found that inflammatory bowel disease (IBD) is associated with an increased risk of non-melanoma skin cancer, particularly among patients on immunosuppressive drugs.

New research has now identified a link between IBD and increased risk of melanoma, independent of the use of biologic therapy. Overall, IBD was associated with a 37% increase in melanoma risk, according to the new study in the February issue of Clinical Gastroenterology and Hepatology.

“We evaluated population-based cohort studies and found a small, but apparently real, slightly increased relative risk of melanoma, such that IBD patients have risk that is about 1.4 times higher than the risk in the general population,” says study author Edward V. Loftus, Jr., MD, director of the Inflammatory Bowel Disease Interest Group and professor of medicine at the Mayo Clinic, in Rochester, Minn. 

Loftus and his colleagues performed a systematic review and meta-analysis of cohort studies to determine the risk of melanoma in patients with IBD. They conducted a systematic search of bibliographic databases through March 2013, and included 12 studies in their analysis—studying a total of 172,837 patients with IBD.

From 1940 to 2009, 179 cases of melanoma had been reported. “It appears that Crohn’s disease patients have a slightly higher relative risk than ulcerative colitis patients,” Loftus notes. Patients with Crohn’s disease had a risk 1.8 times higher than baseline; whereas, patients with ulcerative colitis showed a risk 1.2 times higher than baseline.

“We weren’t able to identify a specific subset of patients at particularly increased risk,” he says. “We speculate that an underlying immune dysfunction might increase the risk of melanoma in these patients, but I need to emphasize that is purely speculative.”

The authors concluded that patients diagnosed with IBD should be counseled on their risk for melanoma and educated about protective steps they can take. “All patients with IBD, especially those who are on medications potentially impacting the immune system, should employ sun-protective measures (e.g., use sunscreen, wear hats, avoid tanning booths), and consider seeing a dermatologist on an annual basis for a full skin examination,” Loftus says.

The researchers are currently working on describing cancer risk in a population-based cohort of IBD patients from Olmsted County, Minnesota. Their work has been presented in abstract form at several meetings and the manuscript is in preparation.

—Colleen Mullarkey

Reference

Singh S, Nagpal SJ, Murad MH, Yadav S, Kane SV, Pardi DS, et al. Inflammatory bowel disease is associated with an increased risk of melanoma: A systematic review and meta-analysis. Clin Gastroenterol Hepatol. 2014 Feb;12(2):210-8.