Effect of Mandatory 6-Month Waiting Period on Waitlist and Transplant Outcomes in Patients With Hepatocellular Carcinoma.

Abstract

Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) policy mandates a 6-month waiting period before exception scores are granted to liver transplant candidates with hepatocellular carcinoma (HCC). This study aims to evaluate waitlist and posttransplant outcomes in patients with HCC, before and after implementation of the 6-month waiting rule. We examined two groups from the UNOS registry: Group 1 (pre-6-month rule) consisted of patients registered as transplant candidates with HCC from January 1, 2013, to October 7, 2015 (n=4,814); group 2 (post-6-month rule) consisted of patients registered from October 8, 2015, to June 30, 2018 (n=3,287). As expected, the transplant probability was higher in the first 6months after listing in group 1 than group 2 at 42.0% versus 6.3% (P<0.001). However, the 6-month waitlist mortality/dropout rate was lower in group 2 at 1.2% than group 1 at 4.1% (P<0.001). To assess regional parity of transplant, UNOS regions were categorized into three groups based on Model for End-Stage Liver Disease score at transplant: lower-score (regions 3, 10, and 11), middle-score (1, 2, 6, 8, and 9), and higher-score region groups (4, 5, and 7). Outcomes were compared from the time exception points were given, which we defined as conditional waitlist outcomes. Conditional waitlist mortality/dropout decreased, and transplant probability increased in all region groups, but the benefits of the policy were more pronounced in the higher and middle-score groups, compared with the lower-score group. The decline in waitlist mortality/dropout was only significant in the high Model for End-Stage Liver Disease group (P<0.001). No effect was observed on posttransplant mortality or percent of patients within Milan criteria on explant. The HCC policy change was associated with decreased waitlist mortality/dropout and increased transplant probability. The policy helped to decrease but did not eliminate regional disparities in transplant opportunity without an effect on posttransplant outcomes.