Children With HCC Have Higher Waitlist Mortality for Liver Transplant Than Children With HBL

The waitlist mortality for liver transplant (LT) for pediatric patients with hepatocellular carcinoma (HCC) is significantly higher than that for pediatric patients with hepatoblastoma (HBL), highlighting the need to improve prioritization for children with HCC, according to a study published in Pediatric Blood & Cancer.

LT has established roles in the management for advanced, unresectable disease in pediatric cases of HBL and HCC, but organ allocation policies differ between the 2 groups. The researchers sought to analyze waitlist mortality and posttransplant outcomes, which have not been evaluated in any studies to date.

“Differential allocation in these patients prompts a careful analysis of waitlist-associated morbidity to identify opportunities to optimize equitable access to donor livers,” they explained.

They used data from the United Network for Organ Sharing (UNOS) database, which administers the Organ Procurement and Transplantation Network, to conduct a retrospective cohort study. They identified 688 children with HBL and 95 with HCC listed for first LT. Of the overall 763, 3.5% experienced waitlist mortality.

In 2002, UNOS adopted the MELD/PELD (Model End-Stage Liver Disease/Pediatric End-Stage Liver Disease) scoring systems, and since then “patients with HBL have undergone several iterations of change in organ prioritization designations.” Since 2013, patients with HBL have been granted a more expedited status, the authors explained. “In contrast, pediatric HCC has not seen similar prioritization for organ allocation.”

While children with HBL have effective upfront combination chemotherapy and options for relapse, children with HCC have few treatment alternatives and therapies to get them to an organ transplant.

On average in the study, children with HBL were younger than children with HCC (2 years vs 12 years) and spent fewer days on the waitlist (29 days vs 39 days). Multivariable competing risk regression showed that children with HCC had a waitlist mortality risk that was 3 times higher than that of children with HBL (adjusted subdistribution HR [sHR], 3.08; 95% CI, 1.13-8.37; P = .03). Children with HCC also had an increased risk of unadjusted waitlist mortality (sHR, 4.37; 95% CI, 2.01-9.51; P < .001).

Of the 671 patients who underwent first LT, 595 had HBL and 76 had HCC, and children with HBL received the transplant at a younger age than children with HCC (2 years vs 12 years). The median waitlist time for children who received LT was 26.0 days for the HBL group and 35.5 days for the HCC group. Children with HBL had a longer length of stay after LT compared with HCC, but there was no difference in unadjusted patient survival or graft survival between the groups.

The authors found the following:

• 1-year survival rate was 89.9% for HBL vs 94.4% for HCC
• 3-year survival rate was 83.4% for HBL vs 81.6% for HCC
• 5-year survival rate was 82.0% for HBL vs 78.0% for HCC
• 1-year graft survival rate was 85.2% for HBL vs 91.9% for HCC
• 3-year graft survival rate was 77.6% for HBL vs 78.2% for HCC
• 5-year graft survival rate was 75.9% for HBL vs 74.7% for HCC

The authors speculated that the differences in age, size, and graft type between patients with pediatric HCC and HBL may contribute to the differential allocation and access to deceased organs.

“These findings highlight an opportunity to further adjust prioritization for equitable organ allocation in children with HCC, who may have reduced access to size-appropriate deceased donor organs and less effective bridge-to-transplant therapies compared to children with HBL,” the authors concluded.

Reference

Wu WK, Ziogas IA, Matsuoka LK, et al. Waitlist mortality and post-liver transplant outcomes of pediatric patients with hepatocellular carcinoma and hepatoblastoma in the United States. Pediatr Blood Cancer. Published online November 4, 2021. doi:10.1002/pbc.29425