Immune Checkpoint Inhibitors for Advanced Biliary Tract Cancer

BTC is a rare and aggressive cancer disease, bearing an overall dismal prognosis with only finite therapy options. Only combination chemotherapy regimens achieve disease control, which is often only short-lived since the tumor tissue exhibits high resistance to chemotherapy. The emergence of immune checkpoint inhibitors in recent years has significantly improved the survival of cancer patients and thus, has been integrated into the therapeutic management of several solid tumors, including melanoma, colorectal carcinoma (CRC), hepatocellular carcinoma (HCC), triple- negative breast cancer (TNBC), and non-small-cell lung cancer (NSCLC). Investigation of the tumor biology of BTC and results of preliminary studies have shown that BTC may also be amenable to immunomodulation. In this review, we seek to give a comprehensive overview of the role, potential, and clinical significance of ICPI in the management of BTC.