Efficacy and safety of stereotactic body radiation therapy combined with hepatic arterial infusion chemotherapy for hepatocellular carcinoma with portal vein tumor thrombosis:a multicenter propensity score matching study.

Background: Portal vein tumor thrombosis (PVTT) is among the foremost co-morbidities of hepatocellular carcinoma (HCC), characterized by an inexorably grim prognosis and a paucity of viable therapeutic modalities. Regrettably, the conventional standard sorafenib for HCC patients afflicted with portal vein involvement has yielded suboptimal outcomes. Currently, hepatic arterial infusion chemotherapy (HAIC) and stereotactic body radiation therapy(SBRT) have emerged as promising strategies, particularly in advanced HCC cases complicated by portal vein involvement, showcasing notable survival advantages. Currently, there is no research of HAIC combined with SBRT for HCC patients with PVTT. In this study, we embarked on a multicenter retrospective investigation to elucidate the enhanced survival benefits of this combined modality for HCC patients with portal vein involvement. Methods: Retrospectively collected clinical data from three medical centers in China on patients with HCC and combined PVTT received HAIC combined with SBRT or HAIC alone between September 2019 and June 2022 were analyzed. 1:1 Propensity Score Matching(PSM) was employed to balance baseline differences between the groups. Survival benefits were compared across cohorts using the Kaplan-Meier method, with subgroup analysis conducted to further elucidate outcomes. Univariate and multivariate analyses based on the COX proportional hazards regression model were performed to identify risk factors associated with survival prognosis. Safety was assessed by comparing adverse event rates between the groups. Results: In this study, a total of 253 HCC patients with portal vein invasion were included, of whom 79 underwent HAIC combined with SBRT(HAIC-SBRT group) and 174 received HAIC alone(HAIC group). After matching, a total of 146 patients(73 per group) were analyzed. In the matched cohort, the HAIC-SBRT regimen demonstrated significantly superior clinical outcomes compared with HAIC alone. Median overall survival (mOS, 24.5 versus 12.2 months; HR: 0.50, 95% CI: 0.31-0.79; P < 0.001) and median progression-free survival (mPFS, 10.3 versus 6.9 months; HR: 0.67, 95% CI: 0.45-0.99; P = 0.010) were significantly prolonged. The combination therapy also exhibited markedly improved tumor response, achieving superior objective response rates(ORR) for both intrahepatic lesions (61.6% versus 16.4%, P < 0.001) and PVTT (67.1% versus 13.7%, P < 0.001). No statistically significant differences were observed between the two groups in the incidence of grade 1-2 or grade 3-4 adverse events (all P > 0.05). Conclusion: For HCC with portal vein involvement, the combination of HAIC and SBRT is a more promising and tolerable treatment option compared to HAIC alone.