Immunotherapy in Biliary Tract Cancers: Where Are We?

Biliary tract cancers (BTCs) are a heterogenous group of cancers arising from the biliary tract. The hallmark of these cancers is the advanced stage of presentation and a paucity of durable treatment options. Despite the advances in targeted therapy and immunotherapy in solid tumors, systemic cytotoxic chemotherapy has remained the mainstay for cholangiocarcinomas.

With advances in the understanding of the tumor microenvironment, genetic features, and inflammatory milieu, have led to the identification of tumor-infiltrating immune cells as indicators of prognosis and response to treatment in BTC. Through an improved comprehension of immunology, immuno-oncology is becoming another pillar of treatment along with traditional radiation, surgery, cytotoxic chemotherapy, and targeted therapies. This article reviews the evidence for immunotherapy use in cholangiocarcinoma, which still being in infancy, and offers promising new novel options for the management of biliary tract cancers.