Borderline Resectable Classification Identifies Candidates for Conversion Therapy in Unresectable Hepatocellular Carcinoma Treated With Atezolizumab and Bevacizumab

BACKGROUND: Conversion therapy, which seeks to achieve curative treatment following systemic therapy, is increasingly acknowledged in the management of unresectable hepatocellular carcinoma (HCC). However, validated criteria for predicting eligibility for conversion remain unclear. We investigated the utility of the recently proposed borderline resectable (BR) classification combined with the barcelona clinic liver cancer (BCLC) staging system to identify patients most likely to benefit from conversion following atezolizumab plus bevacizumab (ATZ/BEV) therapy. METHODS: In this multicenter retrospective study, 532 patients with unresectable HCC treated with ATZ/BEV were categorized using the BR classification and stratified according to the BCLC stage. We evaluated objective response rate (ORR), conversion rate, and overall survival (OS) and carried out multivariate logistic regression analysis to identify predictors of conversion. RESULTS: Conversion therapy was performed in 5.9% of patients. Among those with BCLC-C HCC, the conversion rate was significantly higher in BR1 HCC than in BR2 HCC (15.2% vs. 2.0% and p < 0.01), and BR1 status was independently associated with conversion (odds ratio 7.0). Patients with BCLC-C/BR1 staging showed the highest ORR (45.0%) and favorable OS after conversion (p = 0.015). In contrast, the BR classification had limited predictive value in patients with BCLC-B HCC. Notably, downstaging from BR1 to resectable status was more common than from BR2, suggesting higher conversion feasibility. CONCLUSIONS: Integrating BR classification with BCLC staging identified BCLC-C/BR1 patients as optimal candidates for conversion therapy after ATZ/BEV treatment. These findings support incorporating anatomical and oncological criteria into systemic strategies to enable curative interventions in advanced HCC.