Abstract
Atezolizumab and bevacizumab show promise for treating hepatocellular carcinoma (HCC), but identifying responsive patients remains challenging, due to tumor heterogeneity. This study explores immune dynamics following this combination therapy. Between 2020 and 2023, 29 patients with advanced HCC who received atezolizumab plus bevacizumab at Severance Hospital, Seoul, were enrolled in this study. Peripheral blood mononuclear cells were analyzed using flow cytometry and statistical methods to assess immune alterations and identify biomarkers. Baseline characteristics showed a diverse HCC cohort with a mean age of 64 years and 82.8% male predominance. Absence of extrahepatic metastasis was associated with better overall survival. Immune responses revealed distinct CD4(+) T-cell phenotypes between the 'partial response (PR) + stable disease (SD)' and 'progressive disease (PD)' groups, with an overall increase in CD8(+) T-cell phenotypes. Patients with higher frequencies of CD8(+)PD-1(+)Ki-67(+) T cells experienced significantly improved overall survival, while those with lower frequencies of CD4(+)Foxp3(+)PD-1(+)LAG3(+) T cells also had notable survival benefits. These findings enhance the overall understanding of immune responses to this combination therapy, facilitating improved patient stratification and personalized therapeutic approaches for HCC.