Transarterial Radioembolization for Hepatocellular Carcinoma with Major Vascular Invasion: A Nationwide Propensity Score-Matched Analysis with Target Trial Emulation.

PURPOSE: To examine National Cancer Database (NCDB) data to comparatively evaluate overall survival (OS) between patients undergoing transarterial radioembolization (TARE) and those undergoing systemic therapy for hepatocellular carcinoma with major vascular invasion (HCC-MVI). METHODS: One thousand five hundred fourteen patients with HCC-MVI undergoing first-line TARE or systemic therapy were identified from the NCDB. OS was compared using propensity score-matched Cox regression and landmark analysis. Efficacy was also compared within a target trial framework. RESULTS: TARE usage doubled between 2010 and 2015. Intervals before treatment were longer for TARE than for systemic therapy (mean [median], 66.5 [60] days vs 46.8 (35) days, respectively, P < .0001). In propensity-score-matched and landmark-time-adjusted analyses, TARE was found to be associated with a hazard ratio of 0.74 (95 % CI, 0.60-0.91; P = .005) and median OS of 7.1 months (95 % CI, 5.0-10.5) versus 4.9 months (95 % CI, 3.9-6.5) for systemically treated patients. In an emulated target trial involving 236 patients with unilobular HCC-MVI, a low number of comorbidities, creatinine levels <2.0 mg/dL, bilirubin levels <2.0 mg/dL, and international normalized ratio <1.7, TARE was found to be associated with a hazard ratio of 0.57 (95 % CI, 0.39-0.83; P = .004) and a median OS of 12.9 months (95 % CI, 7.6-19.2) versus 6.5 months (95 % CI, 3.6-11.1) for the systemic therapy arm. CONCLUSIONS: In propensity-score-matched analyses involving pragmatic and target trial HCC-MVI cohorts, TARE was found to be associated with significant survival benefits compared with systemic therapy. Although not a substitute for prospective trials, these findings suggest that the increasing use of TARE for HCC-MVI is accompanied by improved OS. Further trials of TARE in patients with HCC-MVI are needed, especially to compare with newer systemic therapies.