Background/Aim: Management of inflammatory bowel disease-associated gastrointestinal cancers, including Crohn’s disease-associated cancer and ulcerative colitis-associated cancer, remains challenging because of concerns regarding treatment-related toxicity and limited clinical data. We aimed to investigate the safety of chemotherapy in patients with inflammatory bowel disease-associated gastrointestinal cancer. Patients and Methods: This retrospective study analyzed 21 patients with inflammatory bowel disease–associated gastrointestinal cancer (Crohn’s disease-associated cancer: 10; ulcerative colitis-associated cancer: 11) who received chemotherapy or chemoradiotherapy between 2010 and 2024. Chemotherapy regimens, adverse events, treatment completion rates, and residual small intestinal lengths in patients with Crohn’s disease were evaluated. Results: Oxaliplatin-based chemotherapy was the most commonly used chemotherapeutic regimen. Dose reduction was required in all patients with Crohn’s disease-associated cancer and in 64% of those with ulcerative colitis-associated cancer, primarily because of diarrhea or neurotoxicity. In the Crohn’s disease-associated cancer group, diarrhea occurred in all patients and was significantly more severe in those with shorter residual small intestines (p=0.02). Despite these toxicities, 80% of patients with Crohn’s disease-associated cancer and 55% of those with ulcerative colitis-associated cancer completed the planned chemotherapy regimen. No inflammatory bowel disease flares or need for corticosteroids or biologics occurred during treatment. Chemoradiotherapy was administered to five patients with Crohn’s disease-associated cancer and locally advanced anorectal cancer, with no major safety concerns. Conclusion: Chemotherapy, including chemoradiotherapy, can be safely administered to patients with inflammatory bowel disease-associated gastrointestinal cancer with careful management. In Crohn’s disease-associated cancer, residual small intestinal length is a key factor in predicting gastrointestinal toxicity severity, particularly diarrhea. Individualized dose adjustments and close monitoring are essential to balance cancer treatment efficacy with the unique risks associated with inflammatory bowel disease.
HASEGAWA et al. (Fri,) studied this question.