Conversion Surgery Performed Following Durvalumab Combined With Gemcitabine and Cisplatin in Cholangiocarcinoma: A Case Report.

Abstract

Background/aim: Immunotherapy using immune checkpoint inhibitors (ICIs) has been widely approved for many cancers. ICI therapy has also been performed for unresectable bile duct cancer in recent years. However, there are few reports of conversion surgery following ICI therapy for unresectable or borderline resectable bile duct cancer. Herein, we present a case of conversion surgery following immune checkpoint ICI therapy for unresectable cholangiocarcinoma, focusing on the cancer immune microenvironment of this case.

Case report: A 77-year-old man was diagnosed with borderline resectable, distal bile duct cancer and hilar cholangiocarcinoma. The patient underwent four courses of durvalumab combined with gemcitabine and cisplatin (Dur+GC) therapy. Evaluation of disease progression showed stable disease (SD), and considering the patient's surgical risk, a pancreaticoduodenectomy was performed. Adenocarcinoma components remained, and detailed pathological examinations using immunohistochemistry were performed. Marked infiltration of lymphocytes was observed in both the cancer core area and the margin area. The lymphocytes were positive for CD3 and CD8, with a subset also expressing CD103. PD-L1 expression was weakly positive in the stromal area, and positive cells were likely to be infiltrating macrophages in morphological features. Cancer cells were positive for HLA-A/B/C and beta-2.

Conclusion: CD103+ CD8+ T cells, recently referred to as tissue-resident memory T cells, might be a critical immune cell population involved in ICI-induced anticancer immune responses in cholangiocarcinoma.