Abstract

Importance Women on the liver transplant waiting list are less likely to undergo a transplant than men. Recent approaches to resolving this disparity have involved adjustments to Model for End-Stage Liver Disease (MELD) scoring, but this will not affect candidates who rely on exception scores rather than calculated MELD score, the majority of whom have hepatocellular carcinoma (HCC). Objective To evaluate the association between female sex, candidate size, and access to liver transplant among wait-listed patients with HCC. Design, Setting, and Participants This retrospective cohort study used US transplant registry data of all adult (aged ≥18 years) wait-listed liver transplant candidates receiving an HCC exception score between January 1, 2010, and March 2, 2023. Exposure Wait-listed liver transplant candidate sex. Main Outcomes and Measures The association of female sex with (1) deceased-donor liver transplant (DDLT) and (2) death or waiting list removal for health deterioration were estimated using multivariable competing-risks regression. Results with and without adjustment for candidate height and weight (mediators of the sex disparity) were compared. Results The cohort included 31 725 candidates with HCC (mean [SD] age at receipt of exception, 61.2 [7.1] years; 76.3% men). Compared with men, women had a lower 1-year cumulative incidence of DDLT (50.8% vs 54.0%; P < .001) and a higher 1-year cumulative incidence of death or delisting for health deterioration (16.2% vs 15.0%; P = .002). After adjustment, without accounting for size, women had a lower incidence of DDLT (subdistribution hazard ratio [SHR], 0.92; 95% CI, 0.89-0.95) and higher incidence of death or delisting (SHR, 1.06; 95% CI, 1.00-1.13) compared with men. When adjusting for candidate height and weight, there was no association of female sex with incidence of DDLT or death or delisting. However, at a height cutoff of 166 cm, short women compared with short men were still less likely to undergo a transplant (SHR, 0.93; 95% CI, 0.88-0.99). Conclusions and Relevance In this study, women with HCC were less likely to receive a DDLT and more likely to die while wait-listed than men with HCC; these differences were largely (but not entirely) explained by sex-based differences in candidate size. For candidates listed with exception scores, additional changes to allocation policy are needed to resolve the sex disparity, including solutions to improve access to size-matched donor livers for smaller candidates.