# RETREAT Score Accurately Predicts the Long-Term Risk of HCC Recurrence After Liver Transplantation: A Single-Center Real-Life Validation

## TL;DR

The RETREAT score accurately predicts the long-term risk of liver cancer recurrence after liver transplantation in patients with hepatocellular carcinoma.

## Contribution

The study validates the RETREAT score's predictive ability in a real-life setting with evolving liver transplant eligibility criteria.

## Key findings

- The RETREAT score effectively stratifies patients into low, medium, and high-risk groups for HCC recurrence.
- High-risk patients had a significantly increased hazard ratio for recurrence and lower survival rates.
- The score's predictive power was confirmed in a large single-center cohort with a median follow-up of 64 months.

## Abstract

Hepatocellular carcinoma (HCC) is one of the main indications for liver transplantation (LT). Despite rigorous selection criteria, the risk of HCC recurrence, although low, remains present. Over the years, various models have been developed to improve the ability to predict recurrence, and among these, the RETREAT (Risk Estimation of Tumor Recurrence After Transplant) score is one of the most validated. However, in recent years, LT eligibility criteria for HCC have expanded, as has the increased use of down-staging strategies, thus increasing the heterogeneity of patients considered for LT. In this evolving landscape, predicting tumor recurrence and survival has become even more essential, particularly with regard to the intensity of surveillance and the choice and dosage of immunosuppression in patients at high risk of recurrence. Our retrospective study on a large cohort of patients undergoing LT for HCC confirmed the ability of RETREAT to predict the risk of HCC recurrence.

Background: Liver transplantation (LT) for Hepatocellular carcinoma (HCC) is still burdened by a significant risk of tumor recurrence. The aim of this study was to apply the Risk Estimation of Tumor Recurrence After Transplant (RETREAT) score for prediction of HCC recurrence and survival. Methods: This retrospective study included all adult patients who consecutively underwent LT for HCC from January 2000 to July 2022 at a single institution. Results: During a median follow-up of 64 months, 56 (19%) out of 298 patients [54%, 36% and 10% with a RETREAT score equal to 0/1 (low), 2/3 (medium) and 4–6 (high), respectively] experienced HCC recurrence after a median of 31 months. The HCC recurrence rates at 1, 5 and 10 years were respectively 4%, 16% and 23%. The 5-year RFS for low-, medium- and high-risk groups were 93%, 78% and 58% (p < 0.001), respectively. In the competitive risk analysis, the medium- and high-risk RETREAT groups had respectively a 2.3 HR (p = 0.017) and 6.4 HR (p < 0.001) of HCC recurrence compared with the low-risk group. Overall, 119 patients died [32 (27%) due to HCC recurrence], and the 5-year survival was 74% (95%, 86% and 61% for low-, medium- and high-risk groups, respectively). In the multivariate analysis, the RETREAT score was associated with the overall survival only for the highest risk class, which yielded a 2.5 HR of death compared with the lowest risk categories (p < 0.001). Conclusions: This study validates the RETREAT score and confirms its ability to predict the risk of HCC recurrence.