Supplementary Material for: Immunotherapy-related pancreatitis: a case series of eight patients from a high-volume oncology centre

Introduction
Immune checkpoint inhibitors (ICIs) may lead to immune-related adverse events (irAEs), including the rare complication of immune-related acute pancreatitis (irAP). Current knowledge about irAP is limited to case reports and retrospective studies.

Case Presentations
We retrospectively reviewed eight patients diagnosed with irAP at a high-volume tertiary cancer centre in Chile between 2021 and 2025. Data were collected on cancer type, immunotherapy regimen, symptoms, enzyme levels, imaging, and treatment. The irAP diagnosis was established according to the American Gastroenterological Association criteria. Adverse reactions were graded using CTCAE v5.0.
Of the eight included patients, four had melanoma, two had breast cancer, and two prostate cancer. Seven received PD-1/CTLA-4 combination therapy, and one received anti-PD-1 monotherapy. The median time to the irAP diagnosis was 5 months. Seven patients presented with gastrointestinal symptoms. Enzyme elevations and imaging findings were variable. All patients were treated with systemic corticosteroids, and three required hospitalisation. Four patients were rechallenged with ICIs. Other grade ≥2 irAEs were observed in six patients. No deaths were directly attributable to irAP.

Conclusion
As demonstrated, these manifestations can diverge substantially from those of classical pancreatitis, so establishing an irAP diagnosis requires a comprehensive assessment. Corticosteroids are an effective treatment in most cases, and ICI rechallenge may be feasible in selected patients. This case series adds eight new reports to the limited literature on irAP, underscoring its clinical heterogeneity and the need for tailored management. Further research and detailed case reporting are essential to improve diagnosis and treatment of this rare toxicity.

引言
免疫检查点抑制剂（Immune checkpoint inhibitors, ICIs）可能引发免疫相关不良事件（immune-related adverse events, irAEs），其中包括罕见的免疫相关性急性胰腺炎（immune-related acute pancreatitis, irAP）并发症。目前针对irAP的认知仅局限于个案报告与回顾性研究。

病例报告
我们回顾性分析了2021年至2025年间，智利某大型三级肿瘤中心确诊的8例irAP患者。收集的临床资料包括肿瘤类型、免疫治疗方案、症状、酶学水平、影像学表现及治疗方案。irAP的诊断依据美国胃肠病学会（American Gastroenterological Association）标准确立，不良反应分级采用不良事件通用术语标准（Common Terminology Criteria for Adverse Events, CTCAE）v5.0。

纳入的8例患者中，4例为黑色素瘤，2例为乳腺癌，2例为前列腺癌。其中7例接受PD-1/CTLA-4联合免疫治疗，1例接受抗PD-1单药治疗。irAP的中位确诊时间为5个月。7例患者出现胃肠道症状，酶学升高及影像学表现存在个体差异。所有患者均接受全身性糖皮质激素治疗，3例需住院治疗。4例患者再次接受ICI治疗。6例患者出现其他≥2级的irAEs，无患者因irAP直接死亡。

结论
如本研究所示，irAP的临床表现与经典急性胰腺炎存在显著差异，因此确立irAP诊断需进行全面评估。多数患者使用糖皮质激素治疗有效，部分经筛选的患者可尝试ICI再挑战治疗。本病例系列为当前有限的irAP相关文献新增了8例报告，凸显了该疾病的临床异质性，以及实施个体化管理的必要性。未来需开展更多研究并完善个案报告，以优化这一罕见毒性反应的诊疗方案。