19 - Should Transarterial Chemoembolization Be Applied with Systemic Therapy for Hepatocellular Carcinoma with Hepatic Vein And/or Inferior Vena Cava Tumor Thrombus (CHANCE2505)?: A Multicenter Study

Purpose: Systemic therapy with or without radiotherapy is useful for hepatocellular carcinoma (HCC) with hepatic vein and/or inferior vena cava tumor thrombus (HVTT/IVCTT). However, the efficacy of transarterial chemoembolization (TACE) in such population is still unconfirmed. This study aims to evaluate whether TACE should be applied with systemic therapy for HCC with HVTT/IVCTT, in a first-line therapy setting.

Materials and Methods: This multi-center retrospective cohort study included HCC patients with HVTT/IVCTT treated between June 2018 and March 2024. Patients received either systemic therapy plus TACE (Group A) or systemic therapy alone (Group B). Propensity score matching (PSM) was utilized to balance the baseline characteristics. Four sensitivity analysis including inverse probability of treatment weighting (IPTW) was performed. The primary outcomes were overall survival (OS) and progression-free survival (PFS). Secondary outcomes included objective response rate (ORR) and safety.

Results: A total of 972 HCC patients with HVTT/IVCTT (696 in Group A and 276 in Group B) were included. The median follow-up time was 32.1 (95% CI: 30.4-33.8) months. After PSM, Group A demonstrated a significantly longer median OS compared to Group B (20.9 vs. 14.3 months; HR=0.65, 95% CI: 0.54-0.77, P< 0.0001). Group A achieved a significantly longer median PFS compared to Group B (10.7 vs. 7.3 months; HR=0.67, 95% CI: 0.57-0.79, P< 0.0001, per RECIST v1.1 criteria). Additionally, Group A exhibited a significantly higher objective response rate per RECIST v1.1 (45.3% vs. 28.8%, P< 0.001) and per mRECIST criteria (53.6% vs. 36.3%, P</em>< 0.001). Grade ≥3 treatment-related adverse events occurred in 238 patients in Group A (34.2%) and 87 patients in Group B (31.5%).

Conclusion: TACE in combination with systemic therapy shows improved survival benefit and manageable safety profiles compared systemic therapy alone. These results support the use of TACE alongside first-line systemic therapy for HCC patients with HVTT/IVCTT.