Japanese living donor liver transplantation criteria for hepatocellular carcinoma: nationwide cohort study

Background: Validating the expanded criteria for living donor liver transplantation for hepatocellular carcinoma using national data is highly significant. The aim of this study was to evaluate the validity of the new Japanese criteria for living donor liver transplantation for hepatocellular carcinoma patients and identify factors associated with a poor prognosis using the Japanese national data set. Methods: The study population comprised patients who underwent living donor liver transplantation for hepatocellular carcinoma at 37 centres in Japan between 2010 and 2018. In a nationwide survey, the overall survival and recurrence-free survival rates were evaluated based on the new Japanese criteria for applying the 5-5-500 rule when extending the indication beyond the Milan criteria. Prognostic factors within the Japanese criteria were determined using the Cox proportional hazards model. Results: Patients within (485 patients) and beyond (31 patients) the Japanese criteria exhibited 5-year overall survival rates of 81% and 58% and 5-year recurrence-free survival rates of 77% and 48% respectively. Patients who met the Milan criteria, but not the 5-5-500 rule, had poorer outcomes. Multivariate analysis for 474 patients identified a neutrophil-to-lymphocyte ratio greater than or equal to 5 and a history of hepatectomy as independent risk factors. Conclusion: This nationwide survey confirms the validity of the Japanese criteria. The poor prognostic factors within the Japanese criteria include a neutrophil-to-lymphocyte ratio greater than or equal to 5 and previous hepatectomy.