Mortality after Transplantation for Hepatocellular Carcinoma: A Study from the European Liver Transplant Registry.

Abstract

Prognosis after liver transplantation differs between hepatocellular carcinoma (HCC) arising in cirrhotic and non-cirrhotic livers and aetiology is poorly understood. The aim was to investigate differences in mortality after liver transplantation between these patients. We included patients from the European Liver Transplant Registry transplanted due to HCC from 1990 to November 2016 and compared cirrhotic and non-cirrhotic patients using propensity score (PS) calibration of Cox regression estimates to adjust for unmeasured confounding. We included 22,787 patients, of whom 96.5% had cirrhosis. In the unadjusted analysis, non-cirrhotic patients had an increased risk of overall mortality with a hazard ratio (HR) of 1.37 (95% confidence interval [CI] 1.23-1.52). However, the HR approached unity with increasing adjustment and was 1.11 (95% CI 0.99-1.25) when adjusted for unmeasured confounding. Unadjusted, non-cirrhotic patients had an increased risk of HCC-specific mortality (HR 2.62, 95% CI 2.21-3.12). After adjustment for unmeasured confounding, the risk remained significantly increased (HR 1.62, 95% CI 1.31-2.00). Using PS calibration, we showed that HCC in non-cirrhotic liver has similar overall mortality, but higher HCC-specific mortality. This may be a result of a more aggressive cancer form in the non-cirrhotic liver as higher mortality could not be explained by tumour characteristics or other prognostic variables.