Scientists find possible link between IBD, skin cancer

SAN DIEGO Findings from a new retrospective cohort study recently presented at the American College of Gastroenterology's 74th Annual Scientific meeting here has found that patients with inflammatory bowel disease, especially those receiving the thiopurine class of medications to treat IBD, may be at risk for developing nonmelanoma skin cancer.

Lead researcher Millie Long, of the University of North Carolina, Chapel Hill, examined the records of 26,403 patients with Crohn's disease, and 26,974 patients with ulcerative colitis, dating from 1996 through 2005.

According to the study findings, the incidence rate ratio of NMSC was higher in patients with IBD compared with their matched controls. In addition, recent use of any immunosuppressive medication (within 90 days) was associated with greater risk of NMSC, as was recent use of the thiopurine class of immunosuppressive medications and recent use of biologic medications in patients with Crohn's disease.

"The increased risk of NMSC in patients with IBD is likely related to the immunosuppressive medications used to treat the disease, although we can't rule out changes to the immune system itself as a result of IBD as contributing to this risk," stated Long. "In patients on immunosuppression therapy after organ transplant, previous studies have shown a clear association with NMSC. Other studies have demonstrated that azathioprine, which is in the thiopurine class, can increase the photosensitization of human skin,” Long said.

"Our study demonstrates that patients with IBD on immunosupression may also be at risk for NMSC. As a result, our long-term management plans for IBD patients should stress the daily use of broad-spectrum sunscreen and increased awareness of NMSC to help to prevent complications," Long said.