Resection versus microwave ablation following conversion therapy for unresectable hepatocellular carcinoma

Background & Aims: Conversion therapy may transform some unresectable hepatocellular carcinomas (uHCCs) into curable ones, but data remained limited comparing subsequent curative-intent treatment options. Therefore, we aimed to compare the efficacy and safety of surgical resection (SR) and microwave ablation (MWA) following conversion for initially uHCC. Methods: From June 2008 to October 2022, this multi-center retrospective study included 1035 consecutive patients with treatment-naive BCLC A/B beyond-Milan uHCC receiving curative-intent SR or MWA after successful conversion from 15 tertiary-care hospitals. For the propensity score-matched cohort, overall survival (OS), recurrence-free survival (RFS), and treatment-related complications were compared; a risk-stratification C onversion- A blation or RE section (CARE) score was developed for OS and externally compared against major prognostic models. Results: After matching (421 patients in each treatment group), SR was associated with similar RFS ( p = 0.167), less beyond-Milan recurrence ( p = 0.003), and longer OS ( p < 0.001) compared with MWA. Developed as “10 × baseline AFP (>400 ng/mL,1; ≤ 400 ng/mL,0)-baseline albumin (g/L)-35 × objective response to conversion therapy per mRECIST (yes,1;no,0),” CARE outperformed major prognostic models ( p values, < 0.001 to 0.025) and allowed effective stratification of OS and RFS (all p < 0.001). OS ( p = 0.159) and RFS ( p = 0.573) were similar between the two treatment groups for the CARE-identified low-risk patients (≤-46.6), but SR was associated with longer OS ( p < 0.001) and RFS ( p < 0.001) for the CARE-identified high-risk ones (>-46.6). Treatment-related complications were comparable between two groups ( p values, 0.147 to >0.999). Conclusions: For initially BCLC A/B uHCC beyond the Milan criteria, SR was associated with longer OS and similar RFS compared with MWA after conversion. The CARE score might assist in personalized risk stratification.