High ratio of programmed cell death protein 1 (PD-1)+/CD8+ tumor-infiltrating lymphocytes identifies a poor prognostic subset of extrahepatic bile duct cancer undergoing surgery plus adjuvant chemoradiotherapy

A strong survival impact of the ratio of PD-1+/CD8+ TILs was observed in EHBD cancer. In the poor prognostic subgroup, the blockade of the immune checkpoint in combination with conventional multimodality treatment needs to be considered.