Criteria and prognostic models for patients with hepatocellular carcinoma undergoing liver transplantation

Abstract

Hepatocellular carcinoma (HCC) is a leading cause of cancer-associated death globally. Liver transplantation (LT) has emerged as a key treatment for patients with HCC, and the Milan criteria have been adopted as the cornerstone of the selection policy. To allow more patients to benefit from LT, a number of expanded criteria have been proposed, many of which use radiologic morphological characteristics with larger and more tumors as surrogates to predict outcomes. Other groups developed indices incorporating biological variables and dynamic markers of response to locoregional treatment. These expanded selection criteria achieved satisfactory results with limited liver supplies. In addition, a number of prognostic models have been developed using clinicopathological characteristics, imaging radiomics features, genetic data, and advanced techniques such as artificial intelligence. These models could improve prognostic estimation, establish surveillance strategies, and bolster long-term outcomes in patients with HCC. In this study, we reviewed the latest findings and achievements regarding the selection criteria and post-transplant prognostic models for LT in patients with HCC.

Keywords: Hepatocellular carcinoma; Liver transplantation; Nomogram; Standards.

Figure 1.

Evolving criteria for the selection of patients with hepatocellular carcinoma for liver transplantation. After the introduction of the Milan criteria in 1996, the subsequently expanded criteria mainly focused on the morphological characteristics of the tumor. Starting in 2008, the addition of biological markers facilitated further expansion of the original Milan criteria. More recently, new concepts for patient selection focused on successful downstaging and the response after locoregional or systemic treatment. UCSF, University of California, San Francisco; TTV, total tumor volume; AFP, alpha-fetoprotein; UNOS, United Network for Organ Sharing; TACE, transarterial chemoembolization; TARE, transarterial radioembolization; RFA, radiofrequency ablation; PIVKA-II, vitamin K absence II.

Figure 2.

Features used to develop risk scoring systems for predicting the prognosis of patients with hepatocellular carcinoma after liver transplantation. The parameters included recipient features, tumor clinicopathological characteristics, and serological biomarkers.

Figure 3.

Features of biological marker-based models for predicting the prognosis of patients with hepatocellular carcinoma after liver transplantation. The markers can be divided into tumor proliferation and pathology markers, angiogenesis and inflammatory markers, circulating tumor cells, microRNAs, and metabolic profiling.