Combined immunotherapy for hepatocellular carcinoma: How to maximize immune checkpoint blockade synergic anti-tumor effect

Hepatocellular carcinoma (HCC) is the most prevalent form of liver cancer and has an increasing incidence worldwide. The management of HCC still has many restrictions, despite the fact that there are now numerous treatment options, including liver transplantation/resection, locoregional treatments (LRT), and systemic medication. As a turning point in the history of cancer treatment, the discovery of the immune checkpoints and the development of their inhibitors provide new hope for HCC patients. However, limited objective response rate and insignificant overall survival improvement are still urgent problems to be solved for immune checkpoint inhibitors (ICIs). Combination therapies are considered a solution for improving the effectiveness and response rate of ICIs, and several forms of combination treatments are currently being actively researched. In this review, we summarize the mainstream combination strategies, explain their theoretical basis, introduce several important and ongoing clinical trials, and suggest some potential future paths in this area at the conclusion of the review.