Immunotherapeutic Approaches to Biliary Cancer.

OPINION STATEMENT: Biliary tract cancers (BTCs) are rare aggressive neoplasms with a poor prognosis and a median survival of less than 1 year in the locally advanced or metastatic setting. Among the few patients who undergo curative resection the recurrence rates are high. About 90% of patients are detected at advanced stages, and systemic chemotherapy is the mainstay of their treatment. The treatment options for these patients are limited and multiple modalities of therapy from targeted therapy to immunotherapy and combination therapies (immunotherapy, targeted therapy, and chemotherapy) have been tested in this disease. Targeted therapies have failed to show a survival benefit. The deregulation of the immune system plays a significant role in the pathogenesis of BTCs. Therefore, immunotherapy, especially, immune checkpoint inhibitors hold great promise for this group of cancers. Numerous trials of immunotherapy in BTC are currently ongoing. In this review, we will discuss the available data and evidence for immunotherapy in BTC.