Techniques and status of hepatic arterial infusion chemotherapy for primary hepatobiliary cancers

Primary hepatobiliary cancers (PHCs), which mainly include hepatocellular carcinoma (HCC) and biliary tract cancers (BTCs), are mostly diagnosed in the advanced stage and are not candidates for curative surgery or ablation, resulting in a dismal prognosis. Targeted therapies with or without programmed death receptor 1 (PD-1)/PD-L1 inhibitors have been incorporated into first-line treatments for advanced HCC. Systemic chemotherapy is still the mainstay treatment for advanced BTCs, and combining it with PD-1/PD-L1 inhibitors has resulted in prolonged patient survival. Intra-arterial therapies, including trans-arterial chemoembolization, selective internal radiation therapy, and hepatic arterial infusion chemotherapy (HAIC), have been explored and used for advanced hepatobiliary cancers for many years with positive results, particularly when combined with systemic treatments. Recently, an increasing number of phase II/III trials have demonstrated the efficacy and safety of HAIC for the treatment of advanced HCC with portal vein tumor thrombosis and/or a large tumor burden, for the neoadjuvant and adjuvant treatment of HCC with high-risk factors, and for treating advanced intrahepatic and perihilar cholangiocarcinoma. However, the techniques and regimens used for HAIC are diverse and differ greatly between various regions and centers worldwide. This review focuses on these diverse techniques and regimens, as well as the updated evidence on HAIC regarding the treatment of PHCs.