Efficacy and Safety of Hepatic Arterial Infusion Chemotherapy Combined With Tislelizumab and Regorafenib as First-Line Therapy for Advanced Cholangiocarcinoma

Inclusion Criteria: 1. Age 18-75 years ; 2. Histologically or cytologically confirmed unresectable locally advanced or metastatic intra- or extrahepatic cholangiocarcinoma ; 3. Clinical stage III-IV according to the 8th edition of the AJCC TNM classification ; 4. No prior antitumor therapy; 5. Child-Pugh liver function class A or B ; 6. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2; 7. At least one measurable lesion per RECIST 1.1 ; 8. Adequate haematologic and hepatic/renal function; 9. Total bilirubin ≤ 2× upper limit of normal (patients who have undergone biliary drainage are eligible) ; 10. Adequate cardiac and pulmonary reserves to tolerate interventional procedures ; 11. Signed informed consent, good compliance, and ability to attend follow-up visits. Exclusion Criteria: 1. Contraindications to transarterial chemoembolization, targeted therapy, or immunotherapy ; 2. Prior antitumor treatment ; 3. Concurrent primary malignancies; 4. Child-Pugh class C; 5. Severe cardiac, pulmonary, or renal dysfunction ; 6. Active autoimmune disease or need for long-term immunosuppressive therapy ; 7. Hypersensitivity to contrast agents or study drugs ; 8. Pregnancy or lactation; 9. Anticoagulant or thrombolytic therapy within 3 months before enrollment or bleeding diathesis.