Small graft size and hepatocellular carcinoma outcomes in living donor liver transplantation: a retrospective multicentric cohort study

Abstract

INTRODUCTION: This study examined associations between the graft-to-recipient weight ratio (GRWR) for adult-to-adult living donor liver transplantation (LDLT) and hepatocellular carcinoma (HCC) outcomes. MATERIALS AND METHODS: Data from patients in the Korean Organ Transplantation Registry who underwent LDLT for HCC from 2014 to 2021 were retrospectively reviewed. Patients were categorized using the cutoff GRWR for HCC recurrence determined by an adjusted cubic spline (GRWR <0.7% vs. GRWR ≥0.7%). Recurrence-free survival (RFS) and HCC recurrence were analyzed in the entire and a 1:5 propensity-matched cohort. RESULTS: The eligible cohort consisted of 2005 LDLT recipients [GRWR <0.7 ( n =59) vs. GRWR ≥0.7 ( n =1946)]. In the entire cohort, 5-year RFS was significantly lower in the GRWR <0.7 than in the GRWR ≥0.7 group (66.7% vs. 76.7%, P =0.019), although HCC recurrence was not different between groups (77.1% vs. 80.7%, P =0.234). This trend was similar in the matched cohort ( P =0.014 for RFS and P =0.096 for HCC recurrence). In multivariable analyses, GRWR <0.7 was an independent risk factor for RFS [adjusted hazard ratio (aHR) 1.89, P =0.012], but the result was marginal for HCC recurrence (aHR 1.61, P =0.066). In the pretransplant tumor burden subgroup analysis, GRWR <0.7 was a significant risk factor for both RFS and HCC recurrence only for tumors exceeding the Milan criteria (aHR 3.10, P <0.001 for RFS; aHR 2.92, P =0.003 for HCC recurrence) or with MoRAL scores in the fourth quartile (aHR 3.33, P <0.001 for RFS; aHR 2.61, P =0.019 for HCC recurrence). CONCLUSIONS: A GRWR <0.7 potentially leads to lower RFS and higher HCC recurrence after LDLT when the pretransplant tumor burden is high.