Inflammatory bowel disease (IBD) treatment options, such as anti-tumor necrosis factor (TNF) agents and thiopurines, are associated with an increased risk of certain malignancies. However, the management of IBD patients with prior malignancy is not well defined and the literature is scarce. The main aim of this study was to describe the outcome of IBD patients with prior malignancy, or malignancy before first exposure to IBD-related biologic or immunosuppressive treatment.

The study cohort included adult IBD patients followed in a tertiary academic center, with at least one malignancy diagnosed before IBD diagnosis or before initiation of IBD-related treatment. The main outcome of interest was a relapse of the previous malignancy or development of a second malignancy.

Our database included 1112 patients with both IBD and malignancy. Of these, 86 (9%) who had their malignancy diagnosed before IBD-related treatment initiation were identified, while 10/86 patients (9%) were further diagnosed with a second primary malignancy. Twenty patients, (20/86, 23%) had recurrence of a previous malignancy, most commonly non-melanoma skin cancer (NMSC), found in 9/20 patients (45%). Treatment with infliximab was found to be significantly associated with recurrence of NMSC (P=0.003).

Anti-TNF treatment may be associated with an increased risk of NMSC recurrence. This underscores the importance of rigorous dermatological follow up in IBD patients with previous NMSC treated with anti-TNFs.