Adjuvant Immunotherapy Combined With ChemoRadiation for Patients With High-risk Resectable Extrahepatic Cholangiocarcinoma（AICRC）

The purpose of this prospective, observational study is to investigate whether adjuvant chemoradiotherapy combined with immunotherapy for high-risk recurrence populations after extrahepatic cholangiocarcinoma resection can improve patients' recurrence-free survival. The primary study endpoint of this prospective study is the 2-year recurrence-free survival.