At the October 2009 American College of Gastroenterology (ACG) Annual Science Meeting, lead investigator, Millie Long, MD, presented the results of a new retrospective study on the increased incidences of nonmelanoma skin cancer (NMSC) among patients who have been diagnosed with inflammatory bowel disease (IBD). Patients with IBD are more than 60% more likely to develop NMSC than individuals without IBD. "One in 5 Americans develop skin cancer, which accounts for a third of all cancers in the United States", reports Dr. Long. (1) Nonmelanoma skin cancer is a malignant growth of the epithelial (external) layer of the skin.
Dr. Long, who is affiliated with the University of North Carolina at Chapel Hill, and her colleagues wanted to evaluate the risk for NMSC in patients with IBD and determine if the use of immunosuppressant, biological, and thiopurine medications caused an increase in NMSC risk. Immunosuppressant drugs inhibit the body's immune response and include corticosteriods such as Prednisone. Biological medications, such as Remicade, are produced by living organisms. Thiopurines, such as Imuran, are a class of medications which are used in the treatment of autoimmune disorders.
The researchers examined the records of 26,403 patients with Crohn's disease (CD) and 26,974 patients with ulcerative colitis (UC). The source of the cases was the PharMetrics Patient-Centric Database. The information was gathered from 1996 to 2005. Each IBD patient was matched by age, sex, and region of the country to 3 randomly selected control subjects without Crohn's disease or ulcerative colitis. The mean age of the subjects was approximately 40 years.
Results showed that the annual incidence of NMSC incidence per 100,000 patients was higher in the overall IBD patients than in their matched controls, 773 cases versus 447 cases. Dr. Long correlates the increased risk of NMSC to the use of immunosuppressants in treating IBD. Changes in the immune system, as a result of IBD, as a contributing factor cannot be ruled out. (1)