Downstaging of hepatocellular carcinoma before liver transplantation: Results from a national multi-center prospective cohort study

Background & Aims: Patients with hepatocellular carcinoma (HCC) meeting UNOS-downstaging (DS) criteria have excellent post-liver transplantation (LT) outcomes. Studies on HCC beyond UNOS-DS criteria ("All-comers"(AC)) have been limited by small sample size and short follow-up time, prompting this analysis. Approach & Results: 326 patients meeting UNOS-DS and 190 meeting AC criteria from 9 LT centers across 5 UNOS regions were enrolled from 2015 to 2023 and prospectively followed. Competing risk analysis and Kaplan-Meier method were used to evaluate downstaging and LT outcomes, and Fine-and-Gray and Cox models were used to identify predictors of outcomes. AC and UNOS-DS had similar median alpha-fetoprotein (15 vs. 12 ng/mL;p=0.08), MELD (9 vs. 9;p=0.52), and Child-Pugh (A vs. A;p=0.30). At 2 years from first local regional therapy, 82% of UNOS-DS and 66% of AC were successfully downstaged (p<0.001). In AC, DS rates were 72% for tumor number plus diameter of largest lesion<10, 51% for sum 10-12, and 39% for sum>12 (p=0.01). Y-90 achieved higher DS success than transarterial chemoembolization (TACE) in AC (74% vs. 65%;p<0.001). 48% of UNOS-DS and 40% of AC underwent LT (p=0.10). 5-year post-LT survival was similar between UNOS-DS and AC (74% vs. 72%;p=0.77), although 5-year post-LT recurrence was higher in AC (30% vs. 14%;p=0.02). Conclusions: Despite higher HCC recurrence and lower ITT survival in AC, post-LT survival was comparable between UNOS-DS and AC. Y-90 attained higher DS success than TACE in AC. LT after downstaging is feasible in AC, though defining an upper limit in tumor burden may be necessary.