Advances in immunotherapy for hepatitis B virus associated hepatocellular carcinoma patients

Hepatitis B virus (HBV) infection plays an important role in the occurrence and development of hepatocellular carcinoma (HCC), and the rate of HBV infection in liver cancer patients in China is as high as 92.05%. Due to long-term exposure to chronic antigens from the gut, the liver needs to maintain a certain level of immune tolerance, both to avoid severe inflammation caused by non-pathogenic antigens and to maintain the possibility of rapid and violent responses to infection and tumors. Therefore, HBV infection interacts with the tumor microenvironment (TME) through a highly complex and intertwined signaling pathway, which results in a special TME in HCC. Due to changes in the TME, tumor cells can evade immune surveillance by inhibiting tumor-specific T cell function through cytotoxic T-lymphocy-associated protein-4 (CTLA-4) and programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1). Interferons, as a class of immune factors with strong biological activity, can improve the TME of HBV-HCC through various pathways. In recent years, the systematic treatment of HCC has gradually come out of the dilemma. In addition to the continuous emergence of new multi-target anti-vascular tyrosine kinase inhibitor drugs, immune checkpoint inhibitors have opened up a new avenue for the systematic treatment of HCC. At present, immunotherapy based on PD-1/L1 inhibitors has gradually become a new direction of systematic treatment for HCC, and the disease characteristics of patients included in global clinical studies are different from those of Chinese patients. Therefore, whether a group of HCC patients with HBV background and poor prognosis in China can also benefit from immunotherapy is an issue of wide concern. This review aims to elucidate the advances of immunotherapy for HBV related HCC patients with regard to: (1) Immunotherapy based on interferons; (2) Immunotherapy based on PD-1/L1 inhibitors; (3) Immunotherapy based on CTLA4 inhibitors; (4) Adoptive cell transfer; (5) Combination immunotherapy strategy; and (6) Shortcomings of immunotherapy.