Risk of Lymphoma, Colorectal and Skin Cancer in Patients with IBD Treated with Immunomodulators and Biologics: A Quebec Claims Database Study.

Background: Immunomodulatory medications in patients with inflammatory bowel disease (IBD) have been associated with an increased risk of developing certain malignancies. The aim of this study was to evaluate the risk of melanoma, nonmelanoma skin cancer, colorectal cancer and lymphoma associated with immunomodulators and biologics in patients with IBD.

Methods: A nested case-control study was carried out using the provincial health insurance database of Québec, Canada (RAMQ/MedECHO).

Results: A total of 41,176 patients with IBD were identified of whom 19,582 patients were eligible for inclusion in the study. Treatment with thiopurine for more than 5 years was associated with a significantly increased risk of nonmelanoma skin cancer (odds ratio: 1.78; 95% confidence interval, 1.25-2.54). Immunomodulator treatment was not associated with an increased risk of non-Hodgkin's lymphoma (odds ratio: 0.87; 95% confidence interval, 0.53-1.41). Neither immunomodulators nor anti-TNF-α agents were associated with an increased risk of melanoma or colorectal cancer.

Conclusions: In a large provincial IBD cohort, treatment with immunomodulators for more than 5 years was associated with an increased risk of non-melanoma skin cancer, whereas the risk of lymphoma, melanoma, and colorectal cancer was not increased. No association was found between the risk of the evaluated malignancies and anti-TNF-α medications.