MELD exception points for hepatocellular carcinoma need reassessment

Last Updated: 2017-06-15

By Will Boggs MD

NEW YORK (Reuters Health) - The current Model for End-stage Liver Disease (MELD) allows more exception points for hepatocellular carcinoma (HCC) patients than suggested by outcome-based data, researchers report.

�€œWe have an evidence-based method for the proper assignment of exception points to patients with HCC,�€ Dr. Seth J. Karp from Vanderbilt Transplant Center, Vanderbilt University Medical Center, in Nashville, Tennessee, told Reuters Health by email.

Exception points are intended to equalize waiting list mortality in HCC versus other transplant candidates (LABMELD candidates). Currently, HCC patients can be granted 22 exception points.

Dr. Karp�€™s team used data from the Scientific Registry of Transplant Recipients to develop an evidence-based method for awarding HCC exception points as defined by parity for the waiting list outcome measure of death or removal from the waiting list.

Their final database included more than 67,000 adult liver-transplant candidates, 7,164 of whom received HCC exception points at the time of initial listing (HCC22 candidates).

The national average listing MELD score that resulted in statistically comparable times to adverse events on the waitlist for the LABMELD group compared with the HCC22 group was 16. This demonstrated that HCC22 candidates�€™ times to adverse events were statistically comparable to LABMELD candidates with lower listing laboratory MELD scores, the researchers write in Transplantation, online May 4.

Statistically comparable times to transplant with HCC22 candidates resulted from LABMELD scores of 21-24, depending on region.

LABMELD candidates with 22 exception points were 2.1 times as likely as HCC22 candidates to have waiting-list adverse events and 11% less likely to receive a transplant.

Among LABMELD candidates who showed no improvement after listing, the mean change in MELD was 0.94 per month.

Based on these findings, the researchers say, �€œto equalize waiting list outcomes of death or removal from the list, point awards for patients with HCC should be 16 with an increase of about 1 point per month. Adjusting MELD awards based on regular review of adverse event data would produce an allocation system equipped to reduce the disparity in waiting list outcomes between HCC and non-HCC transplant candidates.�€

For this recommendation (or one like it) to be adopted, Dr. Karp said, �€œthis would have to go through United Network for Organ Sharing (UNOS), in particular the liver intestine committee.�€

Dr. Amit Singal, medical director of University of Texas Southwestern�€™s liver tumor program, in Dallas, told Reuters Health by email, �€œThere has been increasing recognition that HCC patients have an advantage compared to non-HCC patients and there have been several changes to the MELD exception policy since implementation, including decreases in number of MELD exception points in 2003 and 2005."

�€œThe potential issue with simply decreasing exception points any further (as recommended by the authors) is that this would exacerbate regional differences in access to transplantation for HCC patients,�€ he said.

�€œWhereas some regions in the U.S. have an average MELD score at time of transplant in the low-20s, the average MELD in other regions is in the mid-30s,�€ he explained. �€œUnder the policy recommended by the authors, patients with HCC in �€˜high MELD�€™ regions would have to wait for >18 months to get transplanted and the risk of tumor progression beyond Milan criteria (resulting in waitlist drop-out) would be very high.�€

�€œTo address this issue of disparity between HCC and non-HCC patients, there was a recent change in UNOS policy for HCC exception points in 2015,�€ Dr. Singal said. �€œThis policy mandates that patients are listed with their natural MELD score and then awarded 28 points after a 6-month waiting period, which then increases every 3 months to a maximum score of 34 points. A modeling study by Heimbach and colleagues suggests this new 6-month delay policy will help reduce geographic variability in disparity of transplant access between HCC and non-HCC patients.�€

�€œUltimately, no system is perfect but the way in which organ allocation is determined is constantly under review and modified in order to minimize disadvantaging any group of patients or any region of the country over another,�€ he concluded. �€œThis article discusses an important topic given the increasing proportion of the transplant recipients who are receiving exception points for HCC.�€

SOURCE: http://bit.ly/2sDdjgd

Transplantation 2017.