Systemic therapy for biliary tract cancers.

Biliary tract cancers (BTCs) are invasive carcinomas that arise from the epithelial lining of the gallbladder and bile ducts. These include intrahepatic, perihilar, and distal biliary tree cancers as well as carcinoma arising from the gallbladder. Complete surgical resection offers the only chance for cure; however, only 10% of patients present with early-stage disease and are considered surgical candidates. Among those patients who do undergo "curative" resection, recurrence rates are high; thus, for the majority of BTC patients, systemic chemotherapy is the mainstay of their treatment plan. Patients with unresectable or metastatic BTC have a poor prognosis, with a median overall survival time of <1 year. Despite a paucity of randomized phase III data, a consensus on first-line systemic therapy is emerging. In this review, we discuss the clinical experience with systemic treatment of BTC, focusing on the rationale for a first-line regimen as well as future directions in the field.