Inflammatory Bowel Disease Patients with a History of Cancer: Safety of Immunomodulators in a Multicenter Study

<b>Introduction</b>: The risk of new or recurrent cancer in inflammatory bowel disease (IBD) patients with a history of cancer treated with immunomodulators (IMMs), including conventional immunosuppressors (ISSs), biologics or small molecules is undefined. The primary aim was to assess the frequency of new or recurrent cancer in IBD patients treated with IMMs after first cancer. The secondary aim was to evaluate risk factors for new/recurrent cancer in the same IBD population. <b>Methods</b>: In a retrospective multicenter study, all IBD patients using any IMM after first (index) cancer were enrolled. Inclusion criteria: Crohn's disease (CD) or ulcerative colitis (UC), history of any cancer, detailed clinical history, and follow-up after cancer of ≥6 months. Exclusion criteria: IMM use for ≤3 months. <b>Results</b>: In total, 122 IBD patients (84 CD, 38 UC) treated with IMMs after first cancer were enrolled (age 59.5 [26-89] years). Index cancer included (<i>n</i> = [%]) genitourinary tract cancer (18 [14.8]), non-melanotic skin cancer (NMSC) (17 [13.9]), breast cancer (15 [12.3]), thyroid cancer (13 [10.7]), melanoma (14 [11.4]), colorectal cancer (CRC) (11 [9.0]), hematopoietic cancer (9 [7.4]), prostatic cancer (8 [6.6]), neuroendocrine cancer (4 [3.3]), head and neck cancer (3 [2.5]), liver cancer (3 [2.5]), endometrium cancer (2 [1.6]), lung cancer (1 [0.8]) and others (3 [2.5]). ISSs after cancer included (<i>n</i> = [%]) thiopurines (10 [37]), methotrexate (MTX) (14 [51.9]) and others (3 [11.1]) Biologics included (<i>n</i> = [%]) TNF-inhibitors (36 [32.4]), vedolizumab (60 [53.6]), ustekinumab (45 [40.2]), small molecules (9 [7.3]) and others (6 [5.4]). In a median follow-up of 8 [1-45] years after index cancer, 12/122 (9.8%) patients using IMMs after cancer developed new or recurrent cancer. No risk factors for new/recurrent cancer (i.e., age at diagnosis of cancer, smoke, gender, IBD type, IMM use, duration before or after cancer) were identified. <b>Conclusions</b>: In a multicenter study, ISSs or biologics after cancer were not identified as risk factors for new or recurrent cancer in IBD. However, IMMs were used after a long-term interval from index cancer.