Modern-era successful liver transplantation outcomes in children with hepatic undifferentiated embryonal sarcoma.

Background: Hepatic undifferentiated embryonal sarcoma (HUES) is the third most common primary hepatic malignancy in children. If unresectable, liver transplantation (LT) is the only curative option. Historically, HUES LT outcomes were not favorable; however, modern-era data are lacking. We aimed to describe LT outcomes in children with HUES and compared with LT outcomes in children transplanted for hepatoblastoma (HBL) and non-malignancy indications.

Methods: Children 18 years or younger with HUES who underwent LT from 1987 to 2021 were identified from the Scientific Registry of Transplant Recipients database. Graft and patient survival were studied in HUES and LT recipients with HBL and non-malignancy indications using Kaplan-Meier analysis. Cox regression was used to compare patient and graft survival among groups, controlling for confounders.

Results: Twenty-one children with HUES underwent LT during the study period with a median age at LT of 10 years (IQR: 8-12 years). One and five-year patient survival for HUES recipients was not significantly different from that of recipients with HBL (p = .3) or non-malignancy diagnoses (p = .6). There were no deaths due to HUES recurrence. In multivariable Cox regression, HUES did not increase risk of either patient or graft loss as compared to HBL (HR 2.36, p = .2) or non-malignancy indications (HR 0.74, p = .7).

Conclusion: LT outcomes are more favorable in patients with HUES than historically described, and similar to LT outcomes of patients with HBL and non-malignancy indications. Transplant should be considered for HUES patients with unresectable localized tumors.