Advanced intrahepatic cholangiocarcinoma successfully treated with combined immunotherapy: focusing on the tumor immune microenvironment.

A 61-year-old female patient with advanced intrahepatic cholangiocarcinoma diagnosed based on imaging and tumor biopsy findings was treated with combination therapy comprising gemcitabine, cisplatin, and durvalumab. After eight cycles of therapy comprising gemcitabine, cisplatin, and durvalumab and two subsequent cycles of maintenance immunotherapy, significant tumor shrinkage enabled conversion surgery with R0 resection. The tumor immune microenvironment has a critical role in predicting the efficacy of combined immunotherapy in some types of cancer; however, its role in advanced intrahepatic cholangiocarcinoma remains largely unclear. In the current case, the tumor exhibited increased infiltration of CD8 T cells before treatment, and significant increase in CD8 T-cell infiltration, decrease in Treg/CD8 ratio, and development of tertiary lymphoid structures were observed after treatment. Pretreatment tumor immune microenvironment analyses may predict treatment outcomes and optimize strategies for advanced intrahepatic cholangiocarcinoma. Therapy comprising gemcitabine, cisplatin, and durvalumab and immune-based approaches may enhance personalized medicine for patients with advanced intrahepatic cholangiocarcinoma.