TACE Combined With Anti-PD-1 Antibody in Patients With Advanced Hepatocellular Carcinoma: Study on Efficacy and Immune Microenvironment

Inclusion Criteria: * Age ≥18 years. * BCLC stage C, and stage B who are not amenable to curative or locoregional therapies. * Diagnosis of hepatocellular carcinoma. * At least one measurable site of disease as defined by modified RECIST (mRECIST) criteria with spiral CT scan or MRI. * No prior anticancer therapy, including TACE/HAIC, chemotherapy, targeted therapy, or immunotherapy). * Planned to receive TACE plus anti-PD1 inhibitor as first-line treatment. * ECOG performance status 0-1. * Adequate organ function: * ANC ≥1.5 × 10⁹/L, platelets ≥60 × 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. * 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.