Efficacy of Stereotactic Body Radiation Therapy in Patients With Pd-1 Inhibitor–transarterial Chemoembolization Refractory Intermediate-stage Hepatocellular Carcinoma: a Retrospective Controlled Study

Introduction: Transarterial chemoembolization (TACE) combined with PD-1 inhibitor is a novel and effective combination therapy. However, there is currently a gap in subsequent treatment when patients are diagnosed with PD-1 inhibitors-TACE refractoriness.Methods: This retrospective cohort study included enrolled patients with intermediate stage HCC who were diagnosed with PD-1 inhibitor-TACE refractoriness between January 2019 and December 2020 in the Eastern Hepatobiliary Surgery Hospital and the First Affiliated Hospital of Wenzhou Medical University. They were divided into two cohorts, (1) those who switched from TACE combined with PD-1 to stereotactic body radiation therapy (SBRT) combined with PD-1 and (2) those who continued TACE combined with PD-1. Progression free survival (PFS), overall survival (OS), and tumor response were assessed in both groups after refractory to PD-1 inhibitors combined with TACE.Results: Of the seventy-six patients included in this study, the median PFS was 19.6 months in the SBRT group (n=31) and 10.1 months in the TACE group (n=45, p<0.05). The SBRT group also had a significant higher OS than the TACE group (p<0.05). Objective response rate (ORR) and disease control rate (DCR) were also better in the SBRT group (ORR, 71.0% vs. 15.6%, OR=8.483, 95%CI 3.319-21.680, P < 0.001; DCR, 80.6% vs. 31.1%, OR=9.226, 95%CI 3.096-27.493, P < 0.001). Conclusions: SBRT combined with PD-1 inhibitor improves PFS and OS in patients refractory to PD-1 inhibitor combined with TACE. Therefore, SBRT is recommended in case of failure of treatment with PD-1 inhibitors combined with TACE.