Risk factors and clinical course of inflammatory bowel disease in patients receiving cancer therapy

BACKGROUND: Inflammatory bowel disease (IBD) is associated with chronic inflammation and increased malignancy risk; however, data on the effects of cancer therapies on the clinical course of IBD are limited. We evaluated the effects of cancer therapies on IBD activity and oncologic outcomes. METHODS: This single-center, retrospective study was conducted at a tertiary care cancer center and included patients with IBD and malignancy who received cancer therapy 2015-2023. Patient characteristics and comparisons between patients who did and did not develop gastrointestinal adverse events (GI AEs) related to cancer therapy are presented. RESULTS: The cohort included 1153 patients, predominantly white (85.3%) and female (51.6%). GI AEs occurred in 296 (25.7%) patients. Those who developed GI AEs had more hematologic malignancies (21.6 vs. 14.6%; P = 0.005), stage III-IV cancer (55.1 vs. 45.6%; P < 0.0001), immune checkpoint inhibitor (ICI) use (19.6 vs. 10.7%; P < 0.0001) and active baseline IBD status before cancer therapy (20.0 vs. 14.5%; P = 0.025). Stage III-IV disease (hazard ratio: 2.9, P < 0.0001), GI AEs (hazard ratio: 1.3, P = 0.008), GI AE-related hospitalization (hazard ratio: 2.1, P < 0.0001), and ICI (hazard ratio: 2.0, P < 0.0001) were associated with decreased survival. CONCLUSION: Concurrent management of IBD and cancer poses clinical challenges, particularly with the higher risk of GI AEs (25.7%) that is associated with active baseline IBD status and ICI use. These interactions may compromise treatment and survival. Further research is warranted to clarify the long-term impact of cancer therapies on IBD progression and outcomes.