National Trends and Waitlist Outcomes of Locoregional Therapy Among Liver Transplant Candidates With Hepatocellular Carcinoma in the United States

Abstract

Background & aims: Policy changes in the United States have lengthened overall waiting times for patients with hepatocellular carcinoma (HCC). We investigated temporal trends in utilization of locoregional therapy (LRT) and associated waitlist outcomes among liver transplant (LT) candidates in the United States.

Methods: Data for primary adult LT candidates listed from 2003 to 2018 who received HCC exception were extracted from the Organ Procurement and Transplantation Network database. Explant histology was examined, and multivariable competing risk analysis was used to evaluate the association between LRT type and waitlist dropout.

Results: There were 31,609 eligible patients with at least 1 approved HCC exception, and 34,610 treatments among 24,145 LT candidates. The proportion with at least 1 LRT recorded increased from 42.3% in 2003 to 92.4% in 2018. Chemoembolization remains the most frequent type, followed by thermal ablation, with a notable increase in radioembolization from 3% in 2013 to 19% in 2018. An increased incidence of LRT was observed among patients with tumor burden beyond Milan criteria, higher α-fetoprotein level, and more compensated liver disease. Receipt of any type of LRT was associated with a lower risk of waitlist dropout; there was no significant difference by number of LRTs. In inverse probability of treatment weighting-adjusted analysis, radioembolization or ablation as the first LRT was associated with a reduced risk of waitlist dropout compared with chemoembolization.

Conclusions: In a large nationwide cohort of LT candidates with HCC, LRT, and in particular radioembolization, increasingly was used to bridge to LT. Patients with greater tumor burden and those with more compensated liver disease received more treatments while awaiting LT. Bridging LRT was associated with a lower risk of waitlist dropout.

Keywords: Ablation; Chemoembolization; Liver Cancer; Liver Transplantation; Radioembolization; Waitlist Dropout.

Figure 1.

(A) Number of treatments by year of listing. (B) Proportion of locoregional therapy (LRT) types by year of treatment.

Figure 2.

Distribution of different types of locoregional therapy (LRT) by individual centers over 4 different time periods. The x-axis represents individual centers, ordered by proportion of LRT at that center being chemoembolization. A center must have 10 or more LRTs recorded within the era to be included. Ablation indicates thermal, chemical, or cryoablation.