Adjuvant Immunotherapy Combined With Chemoradiation for Patients With High-risk reseCtable Extrahepatic chOlangiocaRcinoma and gallblaDder Cancer

Inclusion Criteria: 1. Age: 18-70 years; 2. Primary resectable extrahepatic cholangiocarcinoma and gallbladder cancer proved by pathology which underwent radical surgery; 3. Pathology indicates R0 with T2-4 or N1; or R1; 4. ECOG PS 0-1; 5. Adequate hematologic, hepatic and renal function: ANC ≥ 1.5x10\^9/L, Hb ≥ 80g/L, PLT ≥ 100 x10\^9/L, albumin ≥ 28g/L, total bilirubin \< 1.5×ULN, ALT and AST \< 2.5×ULN, CREA\<1.5×ULN; 6. At least 6 months of life expectancy. Exclusion Criteria: 1. Pregnant or breastfeeding women, or expecting to conceive or father children within the projected duration of the trial; 2. Received previous anti-cancer therapies; 3. With purulent, infected or delayed healed wounds; 4. Have risky bleeding events requiring transfusion, operation or local therapies, continuous medication in the past 3 months; 5. Have thromboembolism in the past 6 months, including myocardial infarction, unstable angina, stroke or transient ischemic attack, pulmonary embolism, deep vein thrombosis; 6. Have taken aspirin (\>325mg/day) or other antiplatelet drugs continuously for 10 days or more within 2 weeks before enrolment; 7. Uncontrollable hypertension, systolic pressure\>140mmHg or diastolic pressure\>90mmHg after best medical care, or history of hypertensive crisis or hypertensive encephalopathy; 8. Symptomatic congestive heart failure (NYHA class II-IV). Symptomatic or badly-controlled arrhythmia. Congenital long QT syndrome or modified QTc\>500ms upon screening; 9. Have active autoimmune diseases that require systemic treatment within 2 years before enrolment; 10. Active tuberculosis, having antituberculosis therapy at present or within 1 year; 11. Have a known history of prior invasive malignancies within 5 years before enrolment; 12. Have other uncontrollable comorbidities; 13. Infection of HIV, known syphilis requiring treatment; 14. Allergic to chemotherapeutics.