Hepatic arterial infusion chemotherapy and immune checkpoint inhibitors, alone or in combination, in advanced hepatocellular carcinoma with macrovascular invasion: a single-centre experience in Taiwan

Background: The presence of vascular invasion is associated with poor survival in advanced hepatocellular carcinoma (HCC). We compared the effectiveness of hepatic arterial infusion chemotherapy (HAIC) and immune checkpoint inhibitors (ICIs), alone or in combination, in patients with advanced HCC.Methods: We retrospectively reviewed medical records of adult patients with unresectable HCC and macrovascular invasion (MVI) who were treated with HAIC or ICIs alone or in combination at a single centre in Taiwan. Overall tumour response, vascular thrombi response, overall survival (OS) and progression free survival (PFS) in 130 patients were analysed.Results: The treatment group showed no significant effect on the overall tumour response [objective response rate (ORR), 22.86% for HAIC, 26.09% for ICI, 50.00% for HAIC+ICI; P=0.111], but showed a significant effect on vessel response (objective response rate of tumour thrombi (ORRT), 38.57% for HAIC, 45.65% for ICI, 78.57% for HAIC+ICI; P=0.023). Post-hoc comparisons followed by Bonferroni correction revealed that vessel ORRT was significantly different between the HAIC+ICI and HAIC groups (P=0.014). A significant effect of treatment group on portal vein tumour thrombus (PVTT) was also detected (ORRT, 40.00% for HAIC, 50.00% for ICI, 90.00% for HAIC; P=0.013), with significant difference between the HAIC+ICI and HAIC groups (P=0.005). Patients treated with HAIC, ICI, and HAIC+ICI respectively had 12-month OS rates of 44.9%, 31.4%, and 67.5% (P=0.127) and 12-month PFS rates of 21.2%, 24.6%, and 33.2% (P=0.091). In multivariate analysis of PFS, HAIC+ICI was associated with reduced risk of progression or death compared with HAIC alone (adjusted hazard ratio: 0.46; 95% confidence interval: 0.23-0.94; P=0.032).Conclusions: HAIC combined with ICIs had a superior response of PVTT compared to HAIC alone, and was associated with reduced risk of progression or death. Future studies are needed to address the survival benefit of the combination therapy in advanced HCC with MVI.