Immune checkpoint inhibitors and combinations with other agents in cholangiocarcinoma.

Cholangiocarcinoma consists of a heterogeneous group of malignancies with generally poor prognoses. Immunotherapy has emerged in the treatment landscape of many tumors, offering survival benefits, but data regarding the use of immunotherapy for cholangiocarcinoma remain vague. In this review, the authors analyze differences in the tumor microenvironment and various immune escape mechanisms and discuss available immunotherapy combinations with other agents among completed and ongoing clinical trials, such as chemotherapy, targeted agents, antiangiogenic drugs, local ablative therapies, cancer vaccines, adoptive cell therapy and PARP and TGF-β inhibitors. Ongoing research to identify appropriate biomarkers is warranted. Cholangiocarcinomas are a group of rare tumors. Survival time is limited, due to late diagnosis and advanced symptoms. The small number of patients makes it difficult to carry out clinical trials and find new medicines. Another issue is that there are many different subtypes of this tumor. Each one requires a different approach. Despite these setbacks, new treatment choices have appeared. Medicines that stimulate the immune system to fight cancer cells have changed the current treatment landscape for many tumor types and are very promising in cholangiocarcinomas.