Thermal ablation and immunotherapy for hepatocellular carcinoma: Recent advances and future directions

Figure 1 Combination strategies of thermal ablation and immunotherapy for treatment of hepatocellular carcinoma. The main immunotherapy strategies include ICIs (Anti-PD-1/PD-1/CTLA-4) therapy, cell-based therapies such as ACT, and tumor vaccine therapy. Sustained anti-tumor immune response can be obtained after the combination of TA and immunotherapy. Then the residual and metastatic tumors can be eliminated by cytotoxic T lymphocytes and rechallenged tumors can be inhibited by memory T cells. TA: Thermal ablation; ICIs: Immune checkpoint inhibitors; PD-1: Programmed cell death protein-1, PD-L1: Programmed cell death 1 ligand 1; CTLA-4: Cytotoxic T-lymphocyte-associated protein 4; APC: Antigen presenting cell; ACT: Adoptive cell transfer; NK cells: Natural killer cells; CIKs: Cytokine-induced killer cells; TILs: Tumor-infiltrating lymphocytes; CAR-T: Chimeric antigen receptor T cells; TCR-T: T-cell receptor-gene engineered T cells; CTLs: Cytotoxic T lymphocytes.