Efficacy and Safety Comparison Between PD-1 Inhibitor Combined With Lenvatinib or With Regorafenib For UHCC After Failure of First-line Treatment

Inclusion Criteria: 1. Diagnosed with hepatocellular carcinoma (HCC) based on histological or clinical diagnostic criteria; 2. Classified as unresectable HCC following multidisciplinary assessment; 3. Presence of at least one tumor lesion measurable according to EASL criteria; 4. Patients aged ≥18 years and ≤75 years receiving first-line treatment; 5. Child-Pugh liver function class A/B, Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) score 0-2; 6. Disease progression confirmed by CT/MRI and evaluated according to modified RECIST (mRECIST)/RECIST v1.1 criteria after ≥2 cycles of first-line therapy with bevacizumab (15 mg/kg intravenous infusion, once every 3 weeks) combined with sintilimab (200 mg intravenous infusion, once every 3 weeks); 7. Received ≥2 cycles of post-progression treatment with bevacizumab plus sintilimab, lenvatinib, or regorafenib combined with PD-1 inhibitors; 8. Laboratory parameters: hemoglobin(Hb) ≥8.5 g/dL, white blood cell (WBC) count \>2000/mm³, platelet (PLT) count ≥75,000/mm³, absolute neutrophil count (ANC) \>1500/mm³, total bilirubin ≤30 μmol/L, serum albumin ≥30 g/L, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤5 times the upper limit of normal (ULN), serum creatinine ≤1.5 times ULN, international normalized ratio (INR) ≤1.5, prothrombin time (PT) ≤18 seconds; 9. Availability of complete baseline data, treatment records, and follow-up data (including imaging assessments, laboratory tests, and clinical documentation). Exclusion Criteria: 1. Life expectancy ≤2 months; 2. Presence of intrahepatic cholangiocarcinoma, mixed hepatocellular-cholangiocarcinoma, or other non-HCC malignancies; 3. Active concurrent malignancy or severe comorbid conditions; 4. First-line treatment with other anticancer therapies (chemotherapy, radiotherapy, surgery, or other interventions) concurrently; 5. Known hypersensitivity to study drugs.