Addition of Intra-arterial Therapy to Immunotherapy Improves Outcomes in Unresectable Hepatocellular Carcinoma: Taiwan Multicenter Cohort Study

Introduction: Evidence supporting the combination of immunotherapy with intra-arterial therapy (IAT) for unresectable hepatocellular carcinoma (HCC) remains limited. This study aimed to evaluate whether the addition of IAT to first-line immunotherapy improves survival outcomes. Methods: Using the Taiwan Liver Cancer Association (TLCA) Research Group database, we identified patients with unresectable HCC who initiated first-line immunotherapy between May 2017 and January 2024. Patients with Barcelona Clinic Liver Cancer (BCLC) stage A or D disease, prior liver transplantation, or follow-up of 1 (aHR 1.58, 95% CI: 1.11-2.27; P=0.012), tumor burden beyond the up-to-7 criteria (aHR 1.67, 95% CI: 1.02-2.74; P=0.043), and portal vein invasion (aHR 1.67; 95% CI: 1.19-2.35; P=0.003). Five-year OS was higher in the IAT group than in the control group (28.7% 95% CI: 17.8-46.2 vs. 16.4% 95% CI: 10.7-25.2; P=0.007). Landmark and subgroup analyses consistently supported the OS benefit of IAT. Conclusion: In unresectable HCC, the addition of IAT to first-line immunotherapy improves response rates, prolongs the duration of response, and enhances OS.