Evaluation of the Intention-to-Treat Benefit of Living Donation in Patients with Hepatocellular Carcinoma Awaiting a Liver Transplant

Importance: Living-donor liver transplant (LDLT) offers advantages over deceased-donor liver transplant (DDLT) of improved intention-to-treat outcomes and management of the shortage of deceased-donor allografts. However, conflicting data still exist on the outcomes of LDLT in patients with hepatocellular carcinoma (HCC). Objective: To investigate the potential survival benefit of an LDLT in patients with HCC from the time of waiting list inscription. Design, Setting, and Participants: This multicenter cohort study with an intention-to-treat design analyzed the data of patients aged 18 years or older who had an HCC diagnosis and were on a waiting list for a first transplant. Patients from 12 collaborative centers in Europe, Asia, and the US who were on a transplant waiting list between January 1, 2000, and December 31, 2017, composed the international cohort. The Toronto cohort comprised patients from 1 transplant center in Toronto, Ontario, Canada who were on a waiting list between January 1, 2000, and December 31, 2015. The international cohort centers performed either an LDLT or a DDLT, whereas the Toronto cohort center was selected for its capability to perform both LDLT and DDLT. The benefit of LDLT was tested in the 2 cohorts before and after undergoing an inverse probability of treatment weighting (IPTW) analysis. Data were analyzed from February 1 to May 31, 2020. Main Outcomes and Measures: Intention-to-treat death was defined as a patient death that occurred for any reason and was calculated from the time of waiting list inscription for liver transplant to the last follow-up date (December 31, 2019). Four multivariable Cox proportional hazards regression models for intention-to-treat death were created. Results: A total of 3052 patients were analyzed in the international cohort, of whom 2447 were men (80.2%) and the median (IQR) age at first referral was 58 (53-63) years. The Toronto cohort comprised 906 patients, of whom 743 were men (82.0%) and the median (IQR) age at first referral was 59 (53-63) years. In all the settings, LDLT was an independent protective factor, reducing the risk of overall death by 49% in the pre-IPTW analysis for the international cohort (HR, 0.51; 95% CI, 0.36-0.71; P <.001), 33% in the post-IPTW analysis for the international cohort (HR, 0.67; 95% CI, 0.53-0.85; P =.001), 43% in the pre-IPTW analysis for the Toronto cohort (HR, 0.57; 95% CI, 0.45-0.73; P <.001), and 48% in the post-IPTW analysis for the Toronto cohort (HR, 0.52; 95% CI, 0.42 to 0.65; P <.001). The discriminatory ability of the mathematical models further improved in all of the cases in which LDLT was incorporated. Conclusions and Relevance: This study suggests that having a potential live donor could decrease the intention-to-treat risk of death in patients with HCC who are on a waiting list for a liver transplant. This benefit is associated with the elimination of the dropout risk and has been reported in centers in which both LDLT and DDLT options are equally available.