Different First-line Immunotherapy for Advancer Hepatocellular Carcinoma: A Prospective Observational Study on Efficacy and Immune Microenvironment

Inclusion Criteria: * Age ≥ 18 years at time of study entry. * Barcelona Clinic Liver Cancer stage C, or stage B not amenable to curative or locoregional therapies. * HCC confirmed by radiology, histology or cytology. * No prior systemic therapy for HCC. * At least one measurable site of disease as defined by RECIST1.1criteria with spiral CT scan or MRI. * Child-Pugh scores 5-7, performance status (PS) ≤ 2 (ECOG scale). * Adequate organ function: * ANC ≥1.5 × 10⁹/L, platelets ≥100 × 10⁹/L, hemoglobin ≥9 g/dL. * Total bilirubin ≤1.5 × ULN, AST/ALT ≤3 × ULN (≤5 × ULN if liver metastases). * Creatinine ≤1.5 × ULN or CrCl ≥60 mL/min. * Willing to provide archival/fresh tumor tissue and peripheral blood samples. * Signed informed consent. Exclusion Criteria: * Prior systemic therapy for HCC * Active autoimmune disease requiring immunosuppression. * Active infection requiring IV antibiotics. * HIV-positive or active HBV/HCV infection (HBsAg+ with HBV DNA ≥2000 IU/mL; HCV RNA+). * Symptomatic CNS metastases. * Pregnancy/lactation. * Any condition compromising protocol compliance or data interpretation per investigator.