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

Background and Aims 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 wait-list and posttransplant outcomes in patients with HCC, before and after implementation of the 6-month waiting rule. Approach and Results 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 6 months after listing in group 1 than group 2 at 42.0% versus 6.3% (P < 0.001). However, the 6-month wait-list 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 wait-list outcomes. Conditional wait-list 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 wait-list 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. Conclusions The HCC policy change was associated with decreased wait-list 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.