Predictors of low risk for dropout from the liver transplant waiting list for hepatocellular carcinoma in long wait time regions: Implications for organ allocation.

All patients with hepatocellular carcinoma meeting United Network for Organ Sharing T2 criteria currently receive the same listing priority for liver transplant (LT). A previous study from our center identified a subgroup with a very low risk of waitlist dropout who may not derive immediate LT benefit. To evaluate this issue at a national level, we analyzed within the United Network for Organ Sharing database 2052 patients with T2 hepatocellular carcinoma receiving priority listing from 2011 to 2014 in long wait time regions 1, 5, and 9. Probabilities of waitlist dropout were 18.3% at 1 year and 27% at 2 years. In multivariate analysis, factors associated with a lower risk of waitlist dropout included Model for End-Stage Liver Disease-Na < 15, Child's class A, single 2- to 3-cm lesion, and α-fetoprotein ≤20 ng/mL. The subgroup of 245 (11.9%) patients meeting these 4 criteria at LT listing had a 1-year probability of dropout of 5.5% vs 20% for all others (P < .001). On explant, the low dropout risk group was more likely to have complete tumor necrosis (35.5% vs 24.9%, P = .01) and less likely to exceed Milan criteria (9.9% vs 17.7%, P = .03). We identified a subgroup with a low risk of waitlist dropout who should not receive the same LT listing priority.