JAK Inhibitors and Risk of Cancer in IBD Patients

Abstract

Janus kinase inhibitors, including tofacitinib, filgotinib, and upadacitinib, have emerged as effective therapeutic options for the management of inflammatory bowel diseases (IBDs). By targeting the JAK-STAT signaling pathway, these agents modulate immune responses and reduce inflammation. However, concerns regarding the potential risk of malignancy associated with their use have gained significant attention. The JAK-STAT pathway is not only critical for inflammatory signaling but also plays a pivotal role in cellular growth, differentiation, and tumor surveillance. Observational studies and clinical trial data in rheumatoid arthritis have reported malignancies, including non-melanoma skin cancer and solid tumors, in patients receiving JAK inhibitors, with evidence suggesting variable risks depending on the selectivity of the agent. Current evidence does not suggest an increased risk of oncogenesis in patients with IBDs. Balancing therapeutic efficacy with long-term safety requires ongoing vigilance; patient stratification based on risk factors; and tailored monitoring strategies to mitigate potential adverse effects, including malignancies, during JAK inhibitor therapy. Long-term follow-up data of up to 10 years offer reassuring evidence that JAK inhibitor therapy in IBD patients does not confer an increased risk of malignancies, supporting their continued use within appropriate clinical settings.

Keywords: Crohn’s disease; JAK inhibitor; cancer; filgotinib; inflammatory bowel disease; tofacitinib; ulcerative colitis; upadacitinib.

Figure 1

JAK inhibitors have emerged as effective therapeutic agents for the treatment of IBDs. However, following the publication of the ORAL Surveillance trial in 2022—reporting an increased risk of malignancies with tofacitinib in older RA patients with cardiovascular risk factors—concerns were raised regarding their oncologic safety. This led to regulatory warnings in high-risk populations. Nonetheless, data from IBD cohorts with up to 10 years of follow-up have not confirmed this increased cancer risk, providing reassuring evidence specific to the IBD population.