Present situation and prospect of PD-1 / PD-L1 inhibitors in the treatment of biliary tract cancer

The biliary tract cancer (BTC) is a kind of disease with poor prognosis. Due to the lack of typical clinical manifestations and the effective early diagnosis method, the disease is usually detected at an advanced stage and lost the opportunity of surgical therapy. While the traditional radiotherapy and chemotherapy are limited in the treatment of BTC. The immune system plays an important role in the pathogenesis of BTC. Therefore, the programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) inhibitors may have great potential value in the treatment of BTC. Authors reviewed the latest literatures and tried to find the current situation and prospect of PD-1 / PD-L1 inhibitors in the treatment of BTC.