Standing the test of time: outcomes of a decade of prioritizing patients with hepatocellular carcinoma, results of the UNOS natural geographic experiment

Survival benefit of living donor liver transplant for patients with hepatocellular carcinoma

With the increasing incidence of hepatocellular carcinoma (HCC) in both the United States and globally, the role of liver transplantation in management continues to be an area of active conversation as it is often considered the gold standard in the treatment of HCC. The use of living donor liver transplantation (LDLT) and the indications in the setting of malignancy, both generally and in HCC specifically, are frequently debated. In terms of both overall survival and recurrence-free survival, LDLT is at least equivalent to DDLT, especially when performed for disease within Milan criteria. Emerging and compelling evidence suggests that LDLT is superior to DDLT in treating HCC as there is a significant decrease in waitlist mortality. As the oncologic indications for liver transplantation continue to expand and the gap between organ demand and organ availability continues to worsen, high volumes centers should consider using LDLT to shrink the ever-expanding waitlist.

Immune checkpoint inhibitors in liver transplantation: Current practice, challenges, and opportunities

Immune checkpoint inhibitors are becoming a mainstay of cancer treatment. While first studied and approved for patients with unresectable disease, due to their efficacy, they are becoming increasingly used in the perioperative period across many cancer types. In patients with HCC, immune checkpoint inhibitors have now become the standard of care in the advanced setting and have shown promising results in the adjuvant setting after liver resection. While these drugs continue to show promise, their role in the peritransplant setting still remains a question. In this review, we explore the current use of this class of medications in patients with HCC, as well as the immunologic role of the pathways that they inhibit. We also identify potential for future research opportunities to better understand the role of these medications.

The impact of waiting time and delayed treatment on the outcomes of patients with hepatocellular carcinoma: A systematic review and meta-analysis

Hepatocellular carcinoma (HCC) is the sixth most diagnosed cancer worldwide. Healthcare resource constraints may predispose treatment delays. We aim to review existing literature on whether delayed treatment results in worse outcomes in HCC. PubMed, Embase, The Cochrane Library, and Scopus were systematically searched from inception till December 2022. Primary outcomes were overall survival (OS) and disease-free survival (DFS). Secondary outcomes included post-treatment mortality, readmission rates, and complications. Fourteen studies with a total of 135,389 patients (delayed n = 25,516, no delay n = 109,873) were included. Age, incidence of male patients, Child-Pugh B cirrhosis, and Barcelona Clinic Liver Cancer Stage 0/A HCC were comparable between delayed and no delay groups. Tumor size was significantly smaller in delayed versus no delay group (mean difference, -0.70 cm; 95% confidence interval [CI]: -1.14, 0.26; p = 0.002). More patients received radiofrequency ablation in delayed versus no delay group (OR, 1.22; 95% CI: 1.16, 1.27; p < 0.0001). OS was comparable between delayed and no delay in HCC treatment (hazard ratio [HR], 1.13; 95% CI: 0.99, 1.29; p = 0.07). Comparable DFS between delayed and no delay groups (HR, 0.99; 95% CI: 0.75, 1.30; p = 0.95) was observed. Subgroup analysis of studies that defined treatment delay as > 90 days showed comparable OS in the delayed group (HR, 1.04; 95% CI: 0.93, 1.16; p = 0.51). OS and DFS for delayed treatment were non-inferior compared to no delay, but might be due to better tumor biology/smaller tumor size in the delayed group.

Optimal Liver Transplantation Criteria for Hepatocellular Carcinoma

Liver transplantation continues to be the optimal treatment for hepatocellular carcinoma (HCC). Given the limited organ supply, patient selection for liver transplant must carefully balance tumor progression with risk of recurrence posttransplant. There are several pretransplant selection criteria that incorporate biomarkers as well as imaging modality to risk-stratify patients as we continue to look for the optimal transplant cutoff for patients with HCC, which should be transplant-center specific, and account for organ availability and dynamic response to locoregional therapy.

Benefit and harm of waiting time in liver transplantation for HCC

Liver transplantation is the most successful treatment for limited-stage HCC. The waiting time for liver transplantation (LT) can be a critical factor affecting the oncological prognosis and outcome of patients with HCC. Efficient strategies to optimize waiting time are essential to maximize the benefits of LT and to reduce the harm of delay in transplantation. The ever-increasing demand for donor livers emphasizes the need to improve the organization of the waiting list for transplantation and to optimize organ availability for patients with and without HCC. Current progress in innovations to expand the donor pool includes the implementation of living donor LT and the use of grafts from extended donors. By expanding selection criteria, an increased number of patients are eligible for transplantation, which necessitates criteria to prevent futile transplantations. Thus, the selection criteria for LT have evolved to include not only tumor characteristics but biomarkers as well. Enhancing our understanding of HCC tumor biology through the analysis of subtypes and molecular genetics holds significant promise in advancing the personalized approach for patients. In this review, the effect of waiting time duration on outcome in patients with HCC enlisted for LT is discussed.

Development of a deep pathomics score for predicting hepatocellular carcinoma recurrence after liver transplantation

BACKGROUND AND PURPOSE

Tumor recurrence after liver transplantation (LT) impedes the curative chance for hepatocellular carcinoma (HCC) patients. This study aimed to develop a deep pathomics score (DPS) for predicting tumor recurrence after liver transplantation using deep learning.

PATIENTS AND METHODS

Two datasets of 380 HCC patients who underwent LT were enrolled. Residual convolutional neural networks were used to identify six histological structures of HCC. The individual risk score of each structure and DPS were derived by a modified DeepSurv network. Cox regression analysis and Concordance index were used to evaluate the prognostic significance. The cellular exploration of prognostic immune biomarkers was performed by quantitative and spatial proximity analysis according to three panels of 7-color immunofluorescence.

RESULTS

The overall classification accuracy of HCC tissue was 97%. At the structural level, immune cells were the most significant tissue category for predicting post-LT recurrence (HR 1.907, 95% CI 1.490-2.440). The C-indices of DPS achieved 0.827 and 0.794 in the training and validation cohorts, respectively. Multivariate analysis for recurrence-free survival (RFS) showed that DPS (HR 4.795, 95% CI 3.017-7.619) was an independent risk factor. Patients in the high-risk subgroup had a shorter RFS, larger tumor diameter and a lower proportion of clear tumor borders. At the cellular level, a higher infiltration of intratumoral NK cells was negatively correlated with recurrence risk.

CONCLUSIONS

This study established an effective DPS. Immune cells were the most significant histological structure related to HCC recurrence. DPS performed well in post-LT recurrence prediction and the identification of clinicopathological features.

Impact of waiting time on post-transplant survival for recipients with hepatocellular carcinoma: A natural experiment randomized by blood group

Background & Aims

When listing for liver transplantation, one can transplant as soon as possible or introduce a test-of-time to better select patients, as the tumor's biological behavior is observed. Knowing the degree of harm caused by time itself is essential to advise patients and decide on the maximum duration of the test-of-time. Therefore, we investigated the causal effect of waiting time on post-transplant survival for patients with hepatocellular carcinoma.

Methods

We analyzed the UNOS-OPTN dataset and exploited a natural experiment created by blood groups. Relations between variables and assumptions were described in a causal graph. Selection bias was addressed by inverse probability weighting. Confounding was avoided using instrumental variable analysis, with an additive hazards model in the second stage. The causal effect was evaluated by estimating the difference in 5-year overall survival if all patients waited 2 months instead of 12 months. Upper bounds of the test-of-time were evaluated for probable scenarios by means of simulation.

Results

The F-statistic of the first stage was 86.3. The effect of waiting 12 months vs. 2 months corresponded with a drop in overall survival rate of 5.07% (95% CI 0.277-9.69) and 8.33% (95% CI 0.47-15.60) at 5- and 10-years post-transplant, respectively. The median survival dropped by 3.41 years from 16.21 years (95% CI 15.98-16.60) for those waiting 2 months to 12.80 years (95% CI 10.72-15.90) for those waiting 12 months.

Conclusions

From a patient's perspective, the choice between ablate-and-wait vs. immediate transplantation is in favor of immediate transplantation. From a policy perspective, the extra waiting time can be used to increase the utility of scarce donor livers. However, the duration of the test-of-time is bounded, and it likely should not exceed 8 months.

Impact and implications

When listing patients with liver cancer for transplantation, it is unclear whether a test-of-time or immediate transplantation offer better outcomes at the population level. In this study, we found that increased liver transplant waiting times are detrimental in patients with liver cancer. Furthermore, our simulation showed that a pre-operative observational period can be useful to ensure good donor liver allocation, but that its duration should not exceed 8 months.

Prediction models of hepatocellular carcinoma recurrence after liver transplantation: A comprehensive review

Liver transplantation (LT) is one of the most effective treatments for hepatocellular carcinoma (HCC). Although LT eliminates HCC and greatly reduces recurrence, some patients experience recurrence after LT. Criteria and models for screening patients with a high probability of HCC recurrence after LT, starting with the Milan criteria, have been published. These models have changed over time, but a standard has not been established. We summarized HCC prediction models after LT by focusing on the application of radiologic, serologic, and pathologic factors and recent trends. This review will look at studies that are based on living donor LT and deceased donor LT, as well as studies that downstaging procedures have been performed preoperatively. This ultimately aims to help make decisions for evaluating the HCC state and selecting candidates for LT according to the circumstances of each transplantation center.

Performance of pre-transplant criteria in prediction of hepatocellular carcinoma progression and waitlist dropout

BACKGROUND & AIM

Liver transplantation (LT) selection models for hepatocellular carcinoma (HCC) have not been proposed to predict waitlist dropout because of tumour progression. The aim of this study was to compare the alpha-foetoprotein (AFP) model and other pre-LT models in their prediction of HCC dropout.

METHODS

A multicentre cohort study was conducted in 20 Latin American transplant centres, including 994 listed patients for LT with HCC from 2012 to 2018. Longitudinal tumour characteristics, and patterns of progression were recorded at time of listing, after treatments and at last follow-up over the waitlist period. Competing risk regression models were performed, and model's discrimination was compared estimating Harrell's adapted c-statistics.

RESULTS

HCC dropout rate was significantly higher in patients beyond (24% [95% CI 16-28]) compared to those within Milan criteria (8% [95% IC 5%-12%]; p < .0001), with a SHR of 3.01 [95% CI 2.03-4.47]), adjusted for waiting list time and bridging therapies (c-index 0.63 [95% CI 0.57; 0.69). HCC dropout rates were higher in patients with AFP scores >2 (adjusted SHR of 3.17 [CI 2.13-4.71]), c-index of 0.71 (95% CI 0.65-0.77; p = .09 vs Milan). Similar discrimination power for HCC dropout was observed between the AFP score and the Metroticket 2.0 model. In patients within Milan, an AFP score >2 points discriminated two populations with a higher risk of HCC dropout (SHR 1.68 [95% CI 1.08-2.61]).

CONCLUSIONS

Pre-transplant selection models similarly predicted HCC dropout. However, the AFP model can discriminate a higher risk of dropout among patients within Milan criteria.

Machine learning to predict waitlist dropout among liver transplant candidates with hepatocellular carcinoma

Background

Accurate prediction of outcome among liver transplant candidates with hepatocellular carcinoma (HCC) remains challenging. We developed a prediction model for waitlist dropout among liver transplant candidates with HCC.

Methods

The study included 18,920 adult liver transplant candidates in the United States listed with a diagnosis of HCC, with data provided by the Organ Procurement and Transplantation Network. The primary outcomes were 3‐, 6‐, and 12‐month waitlist dropout, defined as removal from the liver transplant waitlist due to death or clinical deterioration.

Results

Using 1,181 unique variables, the random forest model and Spearman's correlation analyses converged on 12 predictive features involving 5 variables, including AFP (maximum and average), largest tumor size (minimum, average, and most recent), bilirubin (minimum and average), INR (minimum and average), and ascites (maximum, average, and most recent). The final Cox proportional hazards model had a concordance statistic of 0.74 in the validation set. An online calculator was created for clinical use and can be found at: http://hcclivercalc.cloudmedxhealth.com/.

Conclusion

In summary, a simple, interpretable 5‐variable model predicted 3‐, 6‐, and 12‐month waitlist dropout among patients with HCC. This prediction can be used to appropriately prioritize patients with HCC and their imminent need for transplant.

Upper Limits of Downstaging for Hepatocellular Carcinoma in Liver Transplantation

Simple Summary

Currently, most transplant centres worldwide accept patients with hepatocellular carcinoma who underwent successful downstaging. Concurrently, the effectiveness of radiological and systemic therapies used for the downstaging of hepatocellular carcinoma are increasing. It is now more frequently observed that candidates for liver transplantation have an excellent response to downstaging, even if the baseline stage was well beyond the transplantable tumour. Downstaged patients have a higher risk of dropout from the waiting list and post-transplant recurrence if not transplanted in a short time. Since an increasing number of downstaged patients affects the waitlist dynamics, the definition of upper limits of downstaging is becoming a crucial issue. In this narrative review, we summarise current evidence on the downstaging of hepatocellular carcinoma for liver transplantation, including downstaging of patients with macrovascular invasion or extrahepatic metastasis at presentation and employment of the new systemic treatments for hepatocellular carcinoma.

Abstract

In Europe and the United States, approximately 1100 and 1800 liver transplantations, respectively, are performed every year for hepatocellular carcinoma (HCC), compared with an annual incidence of 65,000 and 39,000 new cases, respectively. Because of organ shortages, proper patient selection is crucial, especially for those exceeding the Milan criteria. Downstaging is the reduction of the HCC burden to meet the eligibility criteria for liver transplantation. Many techniques can be used in downstaging, including ablation, chemoembolisation, radioembolisation and systemic treatments, with a reported success rate of 60–70%. In recent years, an increasing number of patient responders to downstaging procedures has been included in the waitlist, generally with a comparable five-year post-transplant survival but with a higher probability of dropout than HCC patients within the Milan criteria. While the Milan criteria are generally accepted as the endpoint of downstaging, the upper limits of tumour burden for downstaging HCC for liver transplantation are controversial. Very challenging situations involve HCC patients with large nodules, macrovascular invasion or even extrahepatic metastasis at baseline who respond to increasingly more effective downstaging procedures and who aspire to be placed on the waitlist for transplantation. This narrative review analyses the most important evidence available on cohorts subjected to “extended” downstaging, including HCC patients over the up-to-seven criteria and over the University of California San Francisco downstaging criteria. We also address surrogate markers of biological aggressiveness, such as alpha-fetoprotein and the response stability to locoregional treatments, which are very useful in selecting responders to downstaging procedures for waitlisting inclusion.

Yttrium-90 Radioembolization for the Treatment of Solitary, Unresectable HCC: The LEGACY Study

BACKGROUND AND AIMS

Locoregional therapies, including yttrium-90 radioembolization, play an important role in the treatment of unresectable HCC. The aim of the LEGACY (Local radioEmbolization using Glass Microspheres for the Assessment of Tumor Control with Y-90) study was to evaluate objective response rate (ORR) and duration of response (DoR) in patients with solitary unresectable HCC treated with yttrium-90 glass microspheres.

APPROACH AND RESULTS

LEGACY is a multicenter, single-arm, retrospective study conducted at three sites that included all eligible, consecutive patients with HCC treated with radioembolization between 2014 and 2017. Eligibility criteria included solitary HCC ≤ 8 cm, Child-Pugh A cirrhosis, and Eastern Cooperative Oncology Group performance status 0-1. Primary endpoints were ORR and DoR based on modified Response Evaluation Criteria in Solid Tumors in the treated area (localized), as evaluated by blinded, independent, central review. Radioembolization was performed with intent of ablative-level dosimetry in a selective fashion when possible. Overall survival was evaluated using Kaplan-Meier and multivariate Cox proportional hazards. Among the 162 patients included, 60.5% were Eastern Cooperative Oncology Group 0, and the median tumor size was 2.7 cm (range: 1-8) according to blinded, independent, central review. Radioembolization served as neoadjuvant therapy for transplantation or resection in 21.0% (34 of 162) and 6.8% (11 of 162) of patients, respectively, and as primary treatment for all others. Median follow-up time was 29.9 months by reverse Kaplan-Meier. ORR (best response) was 88.3% (CI: 82.4-92.4), with 62.2% (CI: 54.1-69.8) exhibiting a DoR ≥ 6 months. Three-year overall survival was 86.6% for all patients and 92.8% for those neoadjuvant patients with resected or transplanted liver.

CONCLUSIONS

In this multicenter study of radioembolization, clinical meaningful response rates and prolonged DoR were observed in the treatment of unresectable, solitary HCC ≤ 8 cm.

Liver Transplantation in Patients with Hepatocellular Carcinoma beyond the Milan Criteria: A Comprehensive Review

The Milan criteria (MC) were developed more than 20 years ago and are still considered the benchmark for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC). However, the strict application of MC might exclude some patients who may receive a clinical benefit of LT. Several expanded criteria have been proposed. Some of these consider pretransplant morphological and biological variables of the tumor, others consider post-LT variables such as the histology of the tumor, and others combine pre- and post-LT variables. More recently, the HCC response to locoregional treatments before transplantation emerged as a surrogate marker of the biological aggressiveness of the tumor to be used as a better selection criterion for LT in patients beyond the MC at presentation. This essential review aims to present the current data on the pretransplant selection criteria for LT in patients with HCC exceeding the MC at presentation based on morphological and histological characteristics of the tumor and to critically discuss those that have been validated in clinical practice. Moreover, the role of HCC biological markers and the tumor response to downstaging procedures as new tools for selecting patients with a tumor burden outside of the MC for LT is evaluated.

Neutrophil-to-Lymphocyte Ratio Predicts High-Risk Explant Features and Waitlist Survival But Is Not Independently Associated With Recurrence or Survival Following Liver Transplantation for Hepatocellular Carcinoma

We assessed the prognostic significance and the clinical stability of the neutrophil-to-lymphocyte ratio (NLR) before liver transplantation (LT) in a large cohort of patients with hepatocellular carcinoma (HCC) from a region with a long waitlist time. A high preoperative NLR ≥5 has been reported to predict poor outcomes following LT for HCC, and the NLR has been incorporated into several prognostic models. We evaluated 758 patients with HCC with Model for End-Stage Liver Disease exceptions and listed for LT from 2002 to 2015 at a single LT center, of which 505 underwent LT and 253 dropped out before LT. The NLR was collected in all patients at LT and, if available, between 15 and 90 days before LT (NLR2) or at dropout. An NLR ≥5 was associated with microvascular invasion (MVI), poorer tumor differentiation, and more advanced pathology on explant. Patients with an NLR ≥5 exhibited no differences in alpha-fetoprotein, tumor burden at listing, or number of locoregional therapies compared with patients with an NLR <5. After a median post-LT follow-up of 4.7 years, overall survival and recurrence rates were similar for patients with an NLR ≥5 versus patients with an NLR <5. The NLR changed frequently, and 47% of patients whose NLR2 was ≥5 had an NLR <5 by LT. The NLR was ≥5 in 47.6% of patients at dropout compared with 14.9% of patients undergoing LT. Although the NLR at LT correlated with MVI and tumor stage at explant, the NLR did not predict post-LT survival or HCC recurrence. The NLR appeared to be a relatively unstable inflammatory marker during the immediate 3 months before LT for HCC.

The Key Role of Staging Definitions for Assessment of Downstaging for Hepatocellular Carcinoma

The success of liver transplant (LT) for hepatocellular carcinoma (HCC) is dependent on accurate tumor staging using validated imaging criteria, and adherence to acceptable criteria based on tumor size and number. Other factors including α-fetoprotein (AFP) and response to local regional therapy (LRT) have now played a larger role in candidate selection. Tumor downstaging is defined as reduction in the size of viable tumors using LRT to meet acceptable criteria for LT, and serves as a selection tool for a subgroup of HCC with more favorable biology. The application of tumor downstaging requires a structured approach involving three key components in tumor staging-initial tumor stage and eligibility criteria, tumor viability assessment following LRT, and target tumor stage prior to LT-and incorporation of AFP into staging and treatment response assessments. In this review, we provide in-depth discussions of the key role of these staging definitions in ensuring successful outcome.

Hepatocellular Carcinoma: Downstaging to Liver Transplantation as Curative Therapy

Hepatocellular carcinoma (HCC) ranks among the leading cancer-related causes of morbidity and mortality worldwide. Downstaging of HCC has prevailed as a key method to curative therapy for patients who present with unresectable HCC outside of the listing criteria for liver transplantation (LT). Even though LT paves the way to lifesaving curative therapy for HCC, perpetually severe organ shortage limits its broader application. Debate over the optimal protocol and assessment of response to downstaging treatment has fueled immense research activity and is pushing the boundaries of LT candidate selection criteria. The implicit obligation of refining downstaging protocol is to ensure the maximization of the transplant survival benefit by taking into account the waitlist life expectancy. In the following review, we critically discuss strategies to best optimize downstaging HCC to LT on the basis of existing literature.

A novel waitlist dropout score for hepatocellular carcinoma - identifying a threshold that predicts worse post-transplant survival

BACKGROUND & AIMS

It has been suggested that patients with hepatocellular carcinoma (HCC) at high risk of wait-list dropout would have done poorly after liver transplantation (LT) because of tumour aggressiveness. To test this hypothesis, we analysed risk of wait-list dropout among patients with HCC in long-wait regions (LWRs) to create a dropout risk score, and applied this score in short (SWRs) and mid-wait regions (MWRs) to evaluate post-LT outcomes. We sought to identify a threshold in dropout risk that predicts worse post-LT outcome.

METHODS

Using the United Network for Organ Sharing database, including all patients with T2 HCC receiving priority listing from 2010 to 2014, a dropout risk score was created from a developmental cohort of 2,092 patients in LWRs, and tested in a validation cohort of 1,735 patients in SWRs and 2,894 patients in MWRs.

RESULTS

On multivariable analysis, 1 tumour (3.1-5 cm) or 2-3 tumours, alpha-fetoprotein (AFP) >20 ng/ml, and increasing Child-Pugh and model for end-stage liver disease-sodium scores significantly predicted wait-list dropout. A dropout risk score using these 4 variables (C-statistic 0.74) was able to stratify 1-year cumulative incidence of dropout from 7.1% with a score ≤7 to 39.5% with a score >23. Patients with a dropout risk score >30 had 5-year post-LT survival of 60.1% vs. 71.8% for those with a score ≤30 (p = 0.004). There were no significant differences in post-LT survival below this threshold.

CONCLUSIONS

This study provided evidence that patients with HCC with the highest dropout risk have aggressive tumour biology that would also result in poor post-LT outcomes when transplanted quickly. Below this threshold risk score of ≤30, priority status for organ allocation could be stratified based on the predicted risks of wait-list dropout without significant differences in post-LT survival.

LAY SUMMARY

Prioritising patients with hepatocellular carcinoma for liver transplant based on risk of wait-list dropout has been considered but may lead to inferior post-transplant survival. In this study of nearly 7,000 patients, we created a threshold dropout risk score based on tumour and liver-related factors beyond which patients with hepatocellular carcinoma will likely have poor post-liver transplant outcomes (60% at 5 years). For patients below this risk score threshold, priority status could be stratified based on the predicted risk of wait-list dropout without compromising post-transplant survival.

Recurrence of hepatocellular carcinoma following liver transplantation

INTRODUCTION

Hepatocellular carcinoma (HCC) is an increasingly common disease with liver transplant (LT) the best long-term therapy for early stage disease. We will review the data for assessing risk and managing recurrence for patients undergoing LT for HCC.

AREAS COVERED

In this review, we will provide an overview of methods of patient risk stratification in the post-transplant period, the data around surveillance for HCC recurrence, and the evidence for and against post-LT adjuvant treatment strategies. Finally, we will provide data regarding treatment options for patients with HCC recurrence after LT. Using an extensive search of original papers and society guidelines, this paper provides a comprehensive review of the data for assessing risk and managing recurrence for patients undergoing LT for HCC.

EXPERT OPINION

The development of multiple post-transplant prognostic scoring systems have allowed for improved assessment of recurrence risk and stratification of patients. However, the ability to translate this information into surveillance and therapeutic strategies that improve patient outcomes still have to be fully demonstrated. Post-LT immunosuppression strategies have been implemented in order to attempt to reduce this risk. Evidence-based strategies for managing recurrent HCC are evolving. We expect that with further understanding of individual patient characteristics will allow for optimal therapeutic selection.

Liver Transplantation Outcomes in a U.S. Multicenter Cohort of 789 Patients With Hepatocellular Carcinoma Presenting Beyond Milan Criteria

BACKGROUND AND AIMS

The Organ Procurement and Transplantation Network recently approved liver transplant (LT) prioritization for patients with hepatocellular carcinoma (HCC) beyond Milan Criteria (MC) who are down-staged (DS) with locoregional therapy (LRT). We evaluated post-LT outcomes, predictors of down-staging, and the impact of LRT in patients with beyond-MC HCC from the U.S. Multicenter HCC Transplant Consortium (20 centers, 2002-2013).

APPROACH AND RESULTS

Clinicopathologic characteristics, overall survival (OS), recurrence-free survival (RFS), and HCC recurrence (HCC-R) were compared between patients within MC (n = 3,570) and beyond MC (n = 789) who were down-staged (DS, n = 465), treated with LRT and not down-staged (LRT-NoDS, n = 242), or untreated (NoLRT-NoDS, n = 82). Five-year post-LT OS and RFS was higher in MC (71.3% and 68.2%) compared with DS (64.3% and 59.5%) and was lowest in NoDS (n = 324; 60.2% and 53.8%; overall P < 0.001). DS patients had superior RFS (60% vs. 54%, P = 0.043) and lower 5-year HCC-R (18% vs. 32%, P < 0.001) compared with NoDS, with further stratification by maximum radiologic tumor diameter (5-year HCC-R of 15.5% in DS/<5 cm and 39.1% in NoDS/>5 cm, P < 0.001). Multivariate predictors of down-staging included alpha-fetoprotein response to LRT, pathologic tumor number and size, and wait time >12 months. LRT-NoDS had greater HCC-R compared with NoLRT-NoDS (34.1% vs. 26.1%, P < 0.001), even after controlling for clinicopathologic variables (hazard ratio [HR] = 2.33, P < 0.001) and inverse probability of treatment-weighted propensity matching (HR = 1.82, P < 0.001).

CONCLUSIONS

In LT recipients with HCC presenting beyond MC, successful down-staging is predicted by wait time, alpha-fetoprotein response to LRT, and tumor burden and results in excellent post-LT outcomes, justifying expansion of LT criteria. In LRT-NoDS patients, higher HCC-R compared with NoLRT-NoDS cannot be explained by clinicopathologic differences, suggesting a potentially aggravating role of LRT in patients with poor tumor biology that warrants further investigation.

Evolution of Liver Transplant Selection Criteria and U.S. Allocation Policy for Patients with Hepatocellular Carcinoma

Liver transplantation (LT) is an optimal treatment option for early-stage unresectable hepatocellular carcinoma (HCC) in patients with cirrhosis as it provides a treatment for underlying liver disease as well as a decreased incidence of recurrent cancer compared with alternative treatment strategies. A primary barrier to LT for HCC is the critical shortage of available liver allografts. The system of prioritization and access to deceased donor transplantation for patient with HCC in the United States has continued to evolve, while variable approaches including no additional priority, are in use around the world. While the Milan criteria remain the most well-established pretransplantation selection criteria, multiple other algorithms which expand beyond Milan have been proposed. The current review focuses on liver allocation for HCC as well as the principles and varied models available for pretransplant patient selection.

The Impact of Allocation Changes on Patients with Hepatocellular Carcinoma

Since the establishment of the Milan criteria, liver transplantation (LT) has been identified as an optimal therapy for selected patients with early stage, unresectable hepatocellular carcinoma (HCC) complicating cirrhosis, although a major limitation is the critical shortage of available deceased donor liver allografts. This review focuses on the evolution of liver allocation for HCC in the United States and what the most recent revisions to the allocation system mean for patients with HCC.

Downstaging to Liver Transplant: Success Involves Choosing the Right Patient

Hepatocellular carcinoma is a rising indication for liver transplantation in the United States. Downstaging, defined as the reduction of tumor burden using local-regional therapy into Milan criteria, opens an avenue to access cure through transplant for patients who traditionally would not qualify. Approaching the selection of downstaging candidates through an assessment of hepatic function, staying within a modest expansion of tumor burden, and incorporation of serologic/imaging markers for tumor biology provide the best chance for successful downstaging. Following well-defined downstaging protocols with built-in failure criteria ensures excellent post-transplant outcomes.

Striving for more just allocation of liver allografts between patients with and without hepatocellular carcinoma: successes and challenges

PURPOSE OF REVIEW

Recently the United Network for Organ Sharing (UNOS) adopted new rules for the allocation of liver allografts for recipients with hepatocellular carcinoma (HCC) in hopes of removing regional variation in HCC practice and regional differences in patient survival. Understanding how previous changes to HCC allocation have both succeeded and failed to match the pretransplant mortality of HCC and non-HCC patients on the waitlist will help us to better evaluate these changes and predict where we may again fail.

RECENT FINDINGS

Previous revisions of the HCC allocation rules were successful in more accurately matching the waitlist mortality of HCC and non-HCC patients. Efforts to select for less aggressive tumor biology have resulted in better disease free and patient survival. Several articles have also supported the practice of using locoregional therapies to downstage the patients to within Milan criteria. New rules seek to reduce the amount of geographic disparity in the allocation system.

SUMMARY

Over time UNOS has steady improved the liver allocation polices to attempt to match pretransplant mortality for patients with HCC and without HCC. The latest changes to the organ allocation rules succeed in implementing some of these best practices. However, one can also predict several ongoing challenges to fair allocation that may not have been addressed by recent changes.

Increased Surgical Complications but Improved Overall Survival with Adult Living Donor Compared to Deceased Donor Liver Transplantation: A Systematic Review and Meta-Analysis

Background

Living donor liver transplantation (LDLT) provides an alternative to deceased donor liver transplantation (DDLT) for patients with end-stage liver disease in the circumstance of scarcity of deceased grafts. However, the outcomes of LDLT remain controversial.

Method

A systematic review and meta-analysis were performed to compare the outcomes of LDLT with DDLT. Twelve outcomes were assessed.

Results

Thirty-nine studies involving 38563 patients were included. LDLT was comparable in red blood cell transfusion, perioperative mortality, length of hospital stay, retransplantation rate, hepatitis C virus recurrence rate, and hepatocellular carcinoma recurrence rate with DDLT. Cold ischemia time was shorter and duration of recipient operation was longer in LDLT. Postoperative intra-abdominal bleeding rate occurred less frequently in LDLT recipients (odds ratio (OR) = 0.64, 95%confidence interval (CI) = 0.46 − 0.88, P = 0.006), but this did not decrease the perioperative mortality. LDLT was associated with significantly higher biliary (OR = 2.23, 95%CI = 1.59 − 3.13, P < 0.00001) and vascular (OR = 2.00, 95%CI = 1.31 − 3.07, P = 0.001) complication rates and better overall survival (OS) (1 year: OR = 1.32, 95%CI = 1.01 − 1.72, P = 0.04; 3 years: OR = 1.39, 95%CI = 1.14 − 1.69, P = 0.0010; and 5 years: OR = 1.33, 95%CI = 1.04 − 1.70, P = 0.02). According to subgroup analysis, biliary complication rate and OS improved dramatically as experience increased, while vascular complication rate could not be improved because it was mainly caused by the difference of the donor type itself.

Conclusions

LDLT remains a valuable option for patients in need of liver transplantation for it provides an excellent alternative to DDLT without compromising recipient outcomes. Further refinement in biliary and vascular reconstruction techniques and the accumulation of liver transplantation centers' experience are the key factors in expanding the application of LDLT.

Predictors of outcome after liver transplantation for hepatocellular carcinoma (HCC) beyond Milan criteria

The Milan criteria have been the cornerstone of selection policies for patients with hepatocellular carcinoma (HCC) awaiting liver transplantation (LT) globally for over two decades. Many groups have proposed the transplantation of patients with larger and more numerous tumors achieving comparable results. Many of these use radiologic morphometric criteria as surrogates for explant pathology to predict outcomes. Several other indices have been developed both within and beyond Milan incorporating biological indices as well as dynamic markers of response to pre-transplant locoregional treatments and waiting time. These have allowed for successful expansion of transplant selection criteria without compromising outcomes with limited organ supplies. In this review we will discuss the predictors of outcome in patients beyond Milan criteria.

Liver transplantation in hepatocellular carcinoma after tumour downstaging (XXL): a randomised, controlled, phase 2b/3 trial

BACKGROUND

Indications for liver transplantation for hepatocellular carcinoma are evolving and so-called expanded criteria remain debated. Locoregional therapies are able to downstage hepatocellular carcinoma from beyond to within the Milan criteria. We aimed to investigate the efficacy of liver transplantation after successful hepatocellular carcinoma downstaging.

METHODS

We did an open-label, multicentre, randomised, controlled trial designed in two phases, 2b and 3, at nine Italian tertiary care and transplantation centres. Patients aged 18-65 years with hepatocellular carcinoma beyond the Milan criteria, absence of macrovascular invasion or extrahepatic spread, 5-year estimated post-transplantation survival of at least 50%, and good liver function (Child-Pugh A-B7) were recruited and underwent tumour downstaging with locoregional, surgical, or systemic therapies according to multidisciplinary decision. After an observation period of 3 months, during which sorafenib was allowed, patients with partial or complete responses according to modified Response Evaluation Criteria in Solid Tumors were randomly assigned (1:1) by an interactive web-response system to liver transplantation or non-transplantation therapies (control group). A block randomisation (block size of 2), stratified by centre and compliance to sorafenib treatment, was applied. Liver transplantation was done with whole or split organs procured from brain-dead donors. The control group received sequences of locoregional and systemic treatment at the time of demonstrated tumour progression. The primary outcomes were 5-year tumour event-free survival for phase 2b and overall survival for phase 3. Analyses were by intention to treat. Organ allocation policy changed during the course of the study and restricted patient accrual to 4 years. This trial is registered with ClinicalTrials.gov, NCT01387503.

FINDINGS

Between March 1, 2011, and March 31, 2015, 74 patients were enrolled. Median duration of downstaging was 6 months (IQR 4-11). 29 patients dropped out before randomisation and 45 were randomly assigned: 23 to the transplantation group versus 22 to the control group. At data cutoff on July 31, 2019, median follow-up was 71 months (IQR 60-85). 5-year tumour event-free survival was 76·8% (95% CI 60·8-96·9) in the transplantation group versus 18·3% (7·1-47·0) in the control group (hazard ratio [HR] 0·20, 95% CI 0·07-0·57; p=0·003). 5-year overall survival was 77·5% (95% CI 61·9-97·1) in the transplantation group versus 31·2% (16·6-58·5) in the control group (HR 0·32, 95% CI 0·11-0·92; p=0·035). The most common registered grade 3-4 serious adverse events were hepatitis C virus recurrence (three [13%] of 23 patients) and acute transplant rejection (two [9%]) in the transplantation group, and post-embolisation syndrome (two [9%] of 22 patients) in the control group. Treatment-related deaths occurred in four patients: two (8%) of 23 patients in the transplantation group (myocardial infarction and multi-organ failure) versus two (9%) of 22 patients in the control group (liver decompensation).

INTERPRETATION

Although results must be interpreted with caution owing to the early closing of the trial, after effective and sustained downstaging of eligible hepatocellular carcinomas beyond the Milan criteria, liver transplantation improved tumour event-free survival and overall survival compared with non-transplantation therapies Post-downstaging tumour response could contribute to the expansion of hepatocellular carcinoma transplantation criteria.

FUNDING

Italian Ministry of Health.

Unfair Advantages for Hepatocellular Carcinoma Patients Listed for Liver Transplant in Short-Wait Regions Following 2015 Hepatocellular Carcinoma Policy Change

For patients with hepatocellular carcinoma (HCC) listed for liver transplantation (LT), United Network for Organ Sharing (UNOS) enacted policy changes in 2015 to improve equity between HCC and non-HCC patients. We evaluated the impact of these changes on regional disparities in wait-list dropout and LT. We included patients in the UNOS database listed with Model for End-Stage Liver Disease HCC exceptions in long-wait regions (LWRs), mid-wait regions (MWRs), and short-wait regions (SWRs) before these policy changes (era 1, January 1 to December 31, 2013) and after (era 2, October 7, 2015, to October 7, 2016). Cumulative incidence of wait-list dropout and LT were evaluated using competing risk regression. Median time to LT increased by 3.6 months (3.1 to 6.7 months) in SWRs and 1.3 months (6.9 to 8.2 months) in MWRs (P < 0.001), with a slight decrease in LWRs (13.4 to 12.9 months; P = 0.02). The 2-year cumulative incidence of dropout increased from 9.7% to 14.8% in SWRs (P = 0.03) and from 18.9% to 22.6% in MWRs (P = 0.18) but decreased in LWRs from 26.7% to 24.8% (P = 0.31). Factors predicting wait-list dropout included listing in era 2 (hazard ratio [HR], 1.17), in LWRs (HR, 2.56), and in MWRs (HR, 1.91). Regional differences in wait-list outcomes decreased with policy changes, but HCC patients in SWRs remain advantaged. Recent policy change may narrow these disparities.

Liver Transplantation Beyond Milan Criteria

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide, being the fifth most common cancer and the third most common cause of cancer-related mortality. The incidence of HCC has been rising in the USA over the last 20 years. Liver transplantation is an optimal treatment option, as it eliminates HCC as well as the underlying liver disease. The Milan criteria (1 lesion greater than or equal to 2 cm and less than or equal to 5 cm, or up to 3 lesions, each greater than or equal to 1 cm and less than or equal to 3 cm) have been adopted by many transplant societies worldwide as the criteria to determine whether patients with HCC can move forward with liver transplantation. However, many believe that the Milan criteria may be too strict in regard to its size requirements for lesions. This has led to a number of expanded criteria for liver transplantation, concerning both overall size and number of lesions, as well as incorporation of other markers of tumor biology. Tumor markers, such as alpha-fetoprotein, can also be used to follow treatment of HCC and possibly exclude patients from transplant. HCC presenting beyond Milan criteria can also be down-staged with locoregional therapy. Monitoring response to locoregional therapy and longer wait times after locoregional therapy prior to transplant can serve as surrogate markers of tumor biology as well.

National Experience on Down-Staging of Hepatocellular Carcinoma Before Liver Transplant: Influence of Tumor Burden, Alpha-Fetoprotein, and Wait Time

BACKGROUND AND AIMS

United Network for Organ Sharing (UNOS) recently implemented a national policy granting priority listing for liver transplantation (LT) in patients who achieved down-staging of hepatocellular carcinoma (HCC) to Milan criteria. We aimed to evaluate the national experience on down-staging by comparing two down-staging groups with (1) tumor burden meeting UNOS down-staging (UNOS-DS) inclusion criteria and (2) "all-comers" (AC-DS) with initial tumor burden beyond UNOS-DS criteria versus patients always within Milan.

APPROACH AND RESULTS

This is a retrospective analysis of the UNOS database of 3,819 patients who underwent LT from 2012 to 2015, classified as always within Milan (n = 3,276), UNOS-DS (n = 422), and AC-DS (n = 121). Median time to LT was 12.8 months in long wait regions, 6.5 months in mid wait regions (MWR), and 2.6 months in short wait regions (SWR). On explant, vascular invasion was found in 23.7% of AC-DS versus 16.9% of UNOS-DS and 14.4% of Milan (P = 0.002). Kaplan-Meier 3-year post-LT survival was 83.2% for Milan, 79.1% for UNOS-DS (P = 0.17 vs. Milan), and 71.4% for AC-DS (P = 0.04 vs. Milan). Within down-staging groups, risk of post-LT death in multivariable analysis was increased in SWR or MWR (hazard ratio [HR], 3.1; P = 0.005) and with alpha-fetoprotein (AFP) ≥ 100 ng/mL at LT (HR, 2.4; P = 0.009). The 3-year HCC recurrence probability was 6.9% for Milan, 12.8% for UNOS-DS, and 16.7% for AC-DS (P < 0.001). In down-staging groups, AFP ≥ 100 (HR, 2.6; P = 0.02) was the only independent predictor of HCC recurrence.

CONCLUSIONS

Our results validated UNOS-DS criteria based on comparable 3-year survival between UNOS-DS and Milan groups. Additional refinements based on AFP and wait time may further improve post-LT outcomes in down-staging groups, especially given that reported 3-year recurrence was higher than in those always within Milan criteria.

Resection vs Transplant Listing for Hepatocellular Carcinoma: An Intention-to-Treat Analysis

BACKGROUND

Liver transplantation (LT) and liver resection (LR) are curative treatment options for patients with hepatocellular carcinoma within the Milan criteria. Severe organ shortage dictates the preference for LR. Our aim was to provide an intention-to-treat retrospective comparison of survival between patients who were placed on waiting lists for LT and those who underwent LR.

METHODS

The medical records of patients with hepatocellular carcinoma within the Milan criteria treated by LR or listed for LT between 2007 and 2016 were reviewed. We performed intention-to-treat analyses of overall survival and recurrence.

RESULTS

There were 54 patients on the waiting list for LT, and 30 of them underwent LR. Thirteen of the 54 patients (24%) were not transplanted because of disease-related mortality or tumor progression. The median waiting time to transplantation was 304 days. The 90-day mortality was higher in transplanted patients (9.8% vs 3.3%, P = .003). Intention-to-treat survival was similar for the LT and LR groups (5-year survival, 47.8% vs 55%, respectively, P = .185). There was a trend toward improved 5-year disease-free survival for listed patients (56.2% vs 26.3% for patients undergoing LR, P = .15).

CONCLUSION

Intention-to-treat survival is similar in patients undergoing LR and those on waiting lists for LT. There is a 24% risk to drop from the transplant list. The higher perioperative mortality among patients undergoing LT is balanced by a higher tumor recurrence rate after LR.

Modeling of implementation of the new Organ Procurement and Transplantation Network/United Network for Organ Sharing policy for patients with hepatocellular carcinoma

Aim: To simulate effects of the new Organ Procurement and Transplantation Network/United Network for Organ Sharing policy on the patients' characteristics and post orthotopic liver transplantation (OLT) outcome. Materials & methods: The United Network for Organ Sharing database was used to identify patients with hepatocellular carcinoma who were listed for OLT 2002-2014. All patients (actual group) versus simulated group with new 6-month delay in assigning Model for End-Stage Liver Disease score exception and Model for End-Stage Liver Disease exception cap of 34 were compared. Results & conclusion: With the new policy, 7,745 (30.4%) of the transplanted patients would have received a delayed transplantation or not be transplanted. The simulated group also showed significantly higher mean overall survival after OLT (p < 0.002) and received more locoreginal treatments (p < 0.001).

Is it Time to Abandon the Milan Criteria?: Results of a Bicoastal US Collaboration to Redefine Hepatocellular Carcinoma Liver Transplantation Selection Policies

OBJECTIVES

European liver transplant (LT) centers have moved away from using the Milan Criteria (MC) for hepatocellular carcinoma (HCC) patient selection, turning to models including tumor biological indices, namely alpha-fetoprotein (AFP). We present the first US model to incorporate an AFP response (AFP-R), with comparisons to MC and French-AFP models (F-AFP).

METHODS

AFP-R was measured as differences between maximum and final pre-LT AFP in HCC patients undergoing LT at 3 US centers (2001 to 2013). Cox and competing risk-regression analyses identified predictors of recurrence-free survival (RFS).

RESULTS

Of 1450 patients, 235 (16.2%) were outside MC. Tumor size, number, and AFP-R were independent predictors of RFS and were assigned weighted points based on Cox-regression analysis. An AFP-R consistently < 200 ng/mL predicted the best outcome. A 3-tiered competing-risk RFS model, the New York/California (NYCA) score, was developed, accurately discriminating between groups (P < 0.001), and correlating with overall survival (P < 0.001). Two hundred one of 235 patients outside MC (85.5%) would be recategorized into NYCA low/acceptable-risk groups. The c-statistic for our NYCA score is 0.731 compared with 0.613 for MC and 0.658 for F-AFP (P < 0.0001).

CONCLUSION

Incorporation of AFP-R into HCC selection criteria allows for MC expansion. As United Network for Organ Sharing considers adding AFP to selection algorithms, the NYCA score provides an objective, user-friendly tool for centers to appropriately risk-stratify patients.

Predictors of low risk for dropout from the liver transplant waiting list for hepatocellular carcinoma in long wait time regions: Implications for organ allocation

All patients with hepatocellular carcinoma meeting United Network for Organ Sharing T2 criteria currently receive the same listing priority for liver transplant (LT). A previous study from our center identified a subgroup with a very low risk of waitlist dropout who may not derive immediate LT benefit. To evaluate this issue at a national level, we analyzed within the United Network for Organ Sharing database 2052 patients with T2 hepatocellular carcinoma receiving priority listing from 2011 to 2014 in long wait time regions 1, 5, and 9. Probabilities of waitlist dropout were 18.3% at 1 year and 27% at 2 years. In multivariate analysis, factors associated with a lower risk of waitlist dropout included Model for End-Stage Liver Disease-Na < 15, Child's class A, single 2- to 3-cm lesion, and α-fetoprotein ≤20 ng/mL. The subgroup of 245 (11.9%) patients meeting these 4 criteria at LT listing had a 1-year probability of dropout of 5.5% vs 20% for all others (P < .001). On explant, the low dropout risk group was more likely to have complete tumor necrosis (35.5% vs 24.9%, P = .01) and less likely to exceed Milan criteria (9.9% vs 17.7%, P = .03). We identified a subgroup with a low risk of waitlist dropout who should not receive the same LT listing priority.

Recent advances in liver transplantation for cancer: The future of transplant oncology

Liver transplantation is widely indicated as a curative treatment for selected patients with hepatocellular carcinoma. However, with recent therapeutic advances, as well as efforts to increase the donor pool, liver transplantation has been carefully expanded to patients with other primary or secondary malignancies in the liver. Cholangiocarcinoma, colorectal and neuroendocrine liver metastases, and hepatic epithelioid haemangioendothelioma are amongst the most relevant new indications. In this review we discuss the fundamental concepts of this ambitious undertaking, as well as the newest indications for liver transplantation, with a special focus on future perspectives within the recently established concept of transplant oncology.

A Point-based Histologic Scoring System for Hepatocellular Carcinoma Can Stratify Risk of Posttransplant Tumor Recurrence

Eligibility for liver transplant is most commonly decided by measuring tumor size and number on radiographic imaging. However, this method often underestimates the extent of disease. Evaluation of tumor histology has been shown to improve risk stratification when compared with imaging-based transplant criteria, but the World Health Organization (WHO) guidelines for grading hepatocellular carcinoma (HCC) are imprecise and require subjective interpretation by the pathologist. We performed a retrospective analysis of 190 explanted livers containing HCC and correlated histologic features with posttransplant recurrence to formulate a three-tiered, point-based scoring system that categorizes tumors as having a low, intermediate, or high risk of recurrence. Our Recurrence Risk Assessment Score (RRAS) evaluates tumor architecture and specific cytologic features-nuclear pleomorphism, cytoplasmic amphophilia, and nuclear-to-cytoplasmic ratio-showing superior stratification of HCC recurrence risk compared with imaging criteria and grade assigned by WHO methodology. Stratifying tumors using RRAS criteria, the rate of recurrence after transplant was 0% among low-risk tumors (compared with 3% of well-differentiated tumors), 12% among intermediate-risk tumors (compared with 15% of moderately differentiated tumors), and 54% among high-risk tumors (compared with 29% of poorly differentiated tumors). Receiver operating characteristic analysis shows significantly improved performance of RRAS criteria in predicting HCC recurrence compared with WHO grade (area under curve of 0.841 and 0.671, respectively; P=0.0061). Our results indicate that evaluation of tumor histology offers superior prediction of recurrence risk following liver transplantation compared with radiographic criteria, and that the RRAS system better stratifies recurrence risk compared with HCC grading by WHO methodology.

The Intention-to-Treat Effect of Bridging Treatments in the Setting of Milan Criteria-In Patients Waiting for Liver Transplantation

In patients with hepatocellular carcinoma (HCC) meeting the Milan criteria (MC), the benefit of locoregional therapies (LRTs) in the context of liver transplantation (LT) is still debated. Initial biases in the selection between treated and untreated patients have yielded conflicting reported results. The study aimed to identify, using a competing risk analysis, risk factors for HCC-dependent LT failure, defined as pretransplant tumor-related delisting or posttransplant recurrence. The study was registered at www.clinicaltrials.gov (identification number NCT03723304). In order to offset the initial limitations of the investigated population, an inverse probability of treatment weighting (IPTW) analysis was used: 1083 MC-in patients (no LRT = 182; LRT = 901) were balanced using 8 variables: age, sex, Model for End-Stage Liver Disease (MELD) value, hepatitis C virus status, hepatitis B virus status, largest lesion diameter, number of nodules, and alpha-fetoprotein (AFP). All the covariates were available at the first referral. After the IPTW, a pseudo-population of 2019 patients listed for LT was analyzed, comparing 2 homogeneous groups of untreated (n = 1077) and LRT-treated (n = 942) patients. Tumor progression after LRT was the most important independent risk factor for HCC-dependent failure (subhazard ratio [SHR], 5.62; P < 0.001). Other independent risk factors were major tumor diameter, AFP, MELD, patient age, male sex, and period of wait-list registration. One single LRT was protective compared with no treatment (SHR, 0.51; P < 0.001). The positive effect was still observed when 2-3 treatments were performed (SHR, 0.66; P = 0.02), but it was lost in the case of ≥4 LRTs (SHR, 0.80; P = 0.27). In conclusion, for MC-in patients, up to 3 LRTs are beneficial for success in intention-to-treat LT patients, with a 49% to 34% reduction in failure risk compared with untreated patients. This benefit is lost if more LRTs are required. A poor response to LRT is associated with a higher risk for HCC-dependent transplant failure.

From a Philosophical Framework to a Valid Prognostic Staging System of the New "Comprehensive Assessment" for Transplantable Hepatocellular Carcinoma

The comprehensive assessment of the transplantable tumor (TT) proposed and included in the last Italian consensus meeting still deserve validation. All consecutive patients with hepatocellular carcinoma (HCC) listed for liver transplant (LT) between January 2005 and December 2015 were post-hoc classified by the tumor/patient stage as assessed at the last re-staging-time (ReS-time) before LT as follow: high-risk-class (HRC) = stages TT_DR, TT_PR; intermediate-risk-class (IRC) = TT0_NT, TT_FR, TT_UT; low-risk-class (LRC) = TT1, TT0_L, TT0_C. Of 376 candidates, 330 received LT and 46 dropped-out. Transplanted patients were: HRC for 159 (48.2%); IRC for 63 (19.0%); LRC for 108 (32.7%). Cumulative incidence function (CIF) of tumor recurrence after LT was 21%, 12%, and 8% at 5-years and 27%, 15%, and 12% at 10-years respectively for HRC, IRC, and LRC (P = 0.011). IRC patients had significantly lower CIF of recurrence after LT if transplanted >2-months from ReS-time (28% vs. 3% for <2 and >2 months, P = 0.031). HRC patients had significantly lower CIF of recurrence after-LT if transplanted <2 months from the ReS-time (10% vs. 33% for <2 and >2 months, P = 0.006). The proposed TT staging system can adequately describe the post-LT recurrence, especially in the LRC and HRC patients. The intermediate-risk-class needs to be better defined and further studies on its ability in defining intention-to-treat survival (ITT) and drop-out are required.

Live donor liver transplantation for patients with hepatocellular carcinoma offers increased survival vs. deceased donation

BACKGROUND & AIMS

There are conflicting reports on the outcomes after live donor liver transplantation in patients with hepatocellular carcinoma (HCC). We aimed to compare the survival of patients with HCC, with a potential live donor (pLDLT) at listing vs. no potential donor (pDDLT), on an intention-to-treat basis.

METHODS

All patients with HCC listed for liver transplantation between 2000-2015 were included. The pLDLT group was comprised of recipients with a potential live donor identified at listing. Patients without a live donor were included in the pDDLT group. Survival was assessed by the Kaplan-Meier method. Multivariable Cox regression was applied to identify potential predictors of mortality.

RESULTS

A total of 219 patients were included in the pLDLT group and 632 patients in the pDDLT group. In the pLDLT group, 57 patients (26%) were beyond the UCSF criteria whereas 119 patients (19%) in the pDDLT group were beyond (p = 0.02). Time on the waiting list was shorter for the pLDLT than the pDDLT group (4.8 [2.9-8.5] months vs. 6.2 [3.0-12.0] months, respectively, p = 0.02). The dropout rate was 32/219 (14.6%) in the pLDLT and 174/632 (27.5%) in the pDDLT group, p <0.001. The 1-, 3- and 5-year intention-to-treat survival rates were 86%, 72% and 68% in the pLDLT vs. 82%, 63% and 57% in the pDDLT group, p = 0.02. Having a potential live donor was a protective factor for death (hazard ratio [HR] 0.67; 95% CI 0.53-0.86). Waiting times of 9-12 months (HR 1.53; 95% CI 1.02-2.31) and ≥12 months (HR 1.69; 95% CI 1.23-2.32) were predictors of death.

CONCLUSION

Having a potential live donor at listing was associated with a significant decrease in the risk of death in patients with HCC in this intention-to-treat analysis. This benefit is related to a lower dropout rate and a shorter waiting period.

LAY SUMMARY

Liver transplantation (LT) offers the best chance of survival for patients with hepatocellular carcinoma and can be performed using grafts from deceased donors or live donors. In this work, we aimed to assess the differences in survival after live donor LT when compared to deceased donor LT. We studied 219 patients listed for live donor LT and 632 patients listed for deceased donor LT. Patients who had a potential live donor at the time of listing had a higher survival rate. Therefore, being listed for a live donor LT was a protective factor against death.

The mRECIST Classification Provides Insight into Tumor Biology for Patients With Hepatocellular Carcinoma Awaiting Liver Transplantation

With recent changes in United Network for Organ Sharing policy, patients in the United States with hepatocellular carcinoma (HCC) are likely to spend more time on the liver transplantation (LT) waiting list. The increasing wait time will allow for an opportunity to assess tumor biology prior to LT. Modified Response Evaluation Criteria in Solid Tumors (mRECIST) paradigm provides such a framework for this assessment, and yet little is understood of its utility as it would apply for patients listed for LT in the United States. Through a collaboration between the University of California, San Francisco, and the Mayo Clinic, Jacksonville, Florida, the experience of 772 patients listed for LT were retrospectively reviewed to study the impact of immediate mRECIST classification following locoregional therapy (LRT) on pre- and post-LT outcomes. Patients who had progression of disease (PD; n = 72), failed to respond to LRT (n = 89) at any time point, or did not achieve radiologic complete response (CR; n = 224) were all at significant risk for wait-list dropout (odds ratio [OR] = 12.11, 4.81, and 2.48; respectively). CR identified a cohort of patients who were at a reduced risk for wait-list dropout. However, 24.9% eventually required further intervention while waiting for transplant, and as many as 82.4% were found to have residual HCC on explant pathology. Failure to respond to LRT was associated with increased risk for recurrence (OR = 3.00) more so than PD (OR = 1.36), suggesting that despite PD, patients who eventually can respond to LRT may represent favorable candidates for LT. In conclusion, for patients awaiting LT, the mRECIST assessment provides critical guidance for patient management. Although PD portends a poor prognosis, our findings suggest that further aggressive LRT should be pursued because a response to LRT may yield acceptable results for patients awaiting LT as well as after LT.

Increasing Liver Transplantation Wait-List Dropout for Hepatocellular Carcinoma With Widening Geographical Disparities: Implications for Organ Allocation

Given the increasing incidence of hepatocellular carcinoma (HCC) and regional variation in liver transplantation (LT) rates for HCC, we investigated temporal and geographic disparities in LT and wait-list dropout. LT candidates receiving Model for End-Stage Liver Disease (MELD) exception from 2005 to 2014 were identified from the United Network for Organ Sharing database (n = 14,320). Temporal differences were compared across 2 eras (2005-2009 and 2010-2014). Regional groups were defined based on median wait time as long-wait region (LWR; regions 1, 5, and 9), mid-wait region (MWR; regions 2, 4, 6, 7, and 8), and short-wait region (SWR; regions 3, 10, and 11). Fine and Gray competing risk regression estimated risk of wait-list dropout as hazard ratios (HRs). The cumulative probability of LT within 3 years was 70% in the LWR versus 81% in the MWR and 91% in the SWR (P < 0.001). From 2005-2009 to 2010-2014, median time to LT increased by 6.0 months (5.6 to 11.6 months) in the LWR compared with 3.8 months (2.6 to 6.4 months) in the MWR and 1.3 months (1.0 to 2.3 months) in the SWR. The cumulative probability of dropout within 3 years was 24% in the LWR versus 16% in the MWR and 8% in the SWR (P < 0.001). From 2005-2009 to 2010-2014, the LWR also had the greatest increase in probability of dropout. Risk of dropout was increased in the LWR (HR, 3.5; P < 0.001) and the MWR (HR, 2.2; P < 0.001) compared with the SWR, and year of MELD exception 2010-2014 (HR, 1.9; P < 0.001) compared with 2005-2009. From 2005-2009 to 2010-2014, intention-to-treat 3-year survival decreased from 69% to 63% in the LWR (P < 0.001), 72% to 69% in the MWR (P = 0.008), and remained at 74% in the SWR (P = 0.48). In conclusion, we observed a significant increase in wait-list dropout in HCC patients in recent years that disproportionately impacted LWR patients. Widening geographical disparities call for changes in allocation policy as well as enhanced efforts at increasing organ donation and utilization.

Excellent Outcomes of Liver Transplantation Following Down-Staging of Hepatocellular Carcinoma to Within Milan Criteria: A Multicenter Study

BACKGROUND & AIMS

Single-center studies have reported excellent outcomes of patients who underwent liver transplantation for hepatocellular carcinoma (HCC) after successful down-staging (reduction of tumor burden with local-regional therapy), but multi-center studies are lacking. We performed a multi-center study, applying a uniform down-staging protocol, to assess outcomes of liver transplantation and performed an intention to treat analysis. We analyzed factors associated with treatment failure, defined as dropout from the liver transplant waitlist due to tumor progression, liver-related death without transplant, or recurrence of HCC after transplant.

METHODS

We performed a retrospective multi-center study of 187 consecutive adults with HCC enrolled in the down-staging protocol at 3 liver transplant centers in California (Region 5), from 2002 through 2012. All patients underwent abdominal imaging 1 month after each local-regional treatment, and at a minimum of once every 3 months. The primary outcome was probability of treatment failure.

RESULTS

Liver transplantation was performed after successful down staging in 109 patients (58%). Tumor explant from only 1 patient had poorly differentiated grade and 7 (6.4%) had vascular invasion. Based on Kaplan-Meier analysis of data collected a median 4.3 years after liver transplantation, 95% of patients would survive 1 year and 80% of patients would survive 5 years; probabilities of recurrence-free survival were 95% and 87%, respectively. There were no center-specific differences in survival in the intention to treat analysis (P = .62), in survival after liver transplantation (P = .95), or in recurrence of HCC (P = .99). Patients were removed from the liver transplantation waitlist due to tumor progression in (n = 59; 32%) or liver-related death without liver transplantation (n = 9; 5%). Factors associated with treatment failure, based on multivariable analysis, were pre-treatment levels of alpha-fetoprotein (AFP) >1000 ng/mL (hazard ratio, 3.3; P < .001) and Child Pugh class B or C (hazard ratio, 1.6; P < .001). The probability of treatment failure at 2 years from the first down-staging procedure was 100% for patients with levels of AFP >1000 and Child Pugh class B or C vs 29.4% for patients with neither risk factor (P < .001).

CONCLUSIONS

In a retrospective, multi-center study on HCC down staging under a uniform protocol, we found patients to have excellent outcomes following liver transplantation, with no center-specific effects. Our findings support application of the down-staging protocol on a broader scale. Patients with Child Pugh class B or C and AFP >1000 are unlikely to benefit from down staging.

Liver transplantation beyond or downstaging within the Milan criteria for hepatocellular carcinoma

Unresectable hepatocellular carcinoma (HCC) is a common indication for liver transplantation (LT). The Milan criteria became standard criteria but expansion beyond the Milan criteria (tumor size and number) have resulted in similar post-transplant outcomes, thus suggesting LT is a viable treatment option for HCC presenting beyond the Milan criteria Areas covered: Expanded criteria and the use of downstaging therapies to meet Milan criteria are reviewed. Surrogates of tumor biology (including biomarkers and response to therapy) are described in detail. The controversy regarding treatment of HCV infection prior to transplant for HCC is addressed. Predictors of post-transplant recurrence and therapeutic options are explored. English-language manuscripts pertaining to LT criteria for HCC, downstaging, and tumor prognosis were reviewed. Effort was made to include manuscripts from throughout the world to ensure the reader a broad international perspective. Expert commentary: Patients can be successfully transplanted with HCC beyond Milan criteria, or patients beyond Milan criteria can be downstaged to within Milan criteria and achieve successful post-liver transplant outcomes. The current reliance on tumor burden (size and number) alone ignores the mounting data supporting the prognostic use of additional surrogates of tumor biology in identifying appropriate candidates.