Comparison of two equivalent MELD scores for hepatocellular carcinoma patients using data from the United Network for Organ Sharing liver transplant waiting list registry

摘要

Hepatocellular carcinoma (HCC) patients have been advantaged on the liver transplant waiting list within the United States, and a 6-month delay and exception point cap have recently been implemented to address this disparity. An alternative approach to prioritization is an HCC-specific scoring model such as the MELD Equivalent (MELDEQ) and the mixed new deMELD. Using data on adult patients added to the UNOS waitlist between 9/30/2009 and 6/30/14, we compared projected dropout and transplant probabilities for HCC patients under these two models. Both scores matched actual non-HCC dropout in groups with scores <22 and improved equity with non-HCC transplant probabilities overall. However, neither score matched non-HCC dropout accurately for scores of 25-40 and projected dropout increased beyond non-HCC probabilities for scores <16. The main differences between the two scores were 1) the MELDEQ assigns 6.85 more points after six months on the waitlist and 2) the deMELD gives greater weight to tumor size and laboratory MELD. Post-transplant survival was lower for patients with scores in the 22-30 range compared to those with scores <16 (p=0.007, MELDEQ; p=0.015, deMELD). While both scores result in better equity of waitlist outcomes compared to scheduled progression, continued development and calibration is recommended.