Immunomodulators and biologic agents are effective in treating inflammatory bowel diseases (IBDs), and recent evidence supports their introduction earlier in the disease course. An important concern to both patients and physicians considering immunosuppression (IS) for the treatment of IBD is the potential associated cancer risk. Several important clinical questions deserve attention with respect to IBD therapy and cancer. First, does medical therapy for IBD predispose to developing cancer? Second, in an IBD patient with a history of cancer, does IBD therapy impact cancer recurrence? Third, once cancer develops in an IBD patient, is the cancer outcome different? Finally, in an IBD patient with current cancer, does the cancer therapy affect IBD outcomes? In a recent multicentric study, patients were identified based on a diagnosis of IBD and cancer with subsequent exposure to anti-tumor necrosis factor α (anti-TNFα arm), thiopurines or methotrexate (antimetabolite arm) or without subsequent IS exposure (control arm). Two hundred and fifty-five patients met the inclusion criteria. Prior cancers included 121 solid, 62 gastrointestinal, 55 dermatologic and 17 hematologic malignancies. During the follow-up period, 75 (29.4%) patients developed incident cancer: 36 (14.1%) a new cancer, 33 (12.9%) a recurrent cancer and 6 (2.4%) a new and recurrent cancer. Incident cancer rate per 100 person-years for patients exposed to anti-TNFα, anti-metabolites and controls was 2.6 with 795 person-years of follow-up, 14.8 with 122 person-years of follow-up and 8.52 with 422 person-years of follow-up, respectively. In this series of IBD patients with a history of cancer, exposure to IS following a cancer diagnosis was not associated with an increased risk of incident cancer compared to patients who did not receive these agents. Prospective data are needed to confirm these findings.
© 2015 S. Karger AG, Basel.