Safety And Efficacy Of Radiotherapy Combined With Anti-PD-1 Immunotherapy In Advanced Hepatocellular Carcinoma

Background:Advanced hepatocellular carcinoma(HCC)accounts for poor clinical outcome,and radiotherapy(RT)can achieve outstanding local control.In recent years,immunotherapy has also achieved excellent results.Radiotherapy and immunotherapy have a synergistic effect theoretically.This study aimed to investigate the safety and clinical significance of RT combined with immune checkpoint blockade(ICB)for advanced HCC.Methods:Patients with advanced HCC who received radiotherapy and immune checkpoint inhibitor combination therapy between July 2018 and February 2021 were included.RT was performed when necessary for curative/palliative purpose.ICB was indicated in patients who develop advanced disease in initial diagnosis or after conventional therapy including locoregional therapy and/or system therapy.Results:A total of 38 patients of HCC were included.Treatment related toxicities were generally tolerable and limited to grades 1 and 2,and grade 3 toxicity(39.5%)were seen in bone marrow suppression and hyperbilirubinemia.The median progression-free survival(PFS)was 5.6 months,and the median overall survival(OS)was 12.9 months.Univariate analysis showed that age≥57 years was a good prognostic factor for PFS and OS,and immunotherapy≥8 cycles(P=0.046)or maintenance≥5 months(P=0.018)was significantly related to a good prognosis.During simultaneous radiotherapy and immunotherapy,total lymphocytes decreased significantly and the immune status decreased,but it could be restored to the baseline level during immune maintenance treatment.Conclusion:Hepatic radiotherapy combined with immunotherapy is safe and feasible.In the process of combination treatment,attention should be paid to the changes of bilirubin.Lymphocyte subsets may be used as a detection and evaluation item.ICB treatment for more than 8 cycles and more than 5 months are significantly correlated with a good prognosis.The preliminary demonstration of the efficacy of radiotherapy combined with immunotherapy requires more research to confirm.