Validation of the α-fetoprotein Model for Hepatocellular Carcinoma Recurrence After Transplantation in an Asian Population

New Scenarios in Liver Transplantation for Hepatocellular Carcinoma

BACKGROUND AND AIMS

Despite liver transplantation (LT) is considered the optimal treatment for hepatocellular carcinoma (HCC), particularly in patients with impaired liver function, the shortage of donors has forced the application of very restrictive criteria for selecting ideal candidates for whom LT can offer the best outcome. With the evolving LT landscape due to the advent of direct-acting antivirals (DAAs) and the steady increase in donors, major efforts have been made to expand the transplant eligibility criteria for HCC. In addition, the emergence of immune checkpoint inhibitors (ICIs) for the treatment of HCC, with demonstrated efficacy in earlier stages, has revolutionized the therapeutic approach for these patients, and their integration in the setting of LT is challenging. Management of immunological compromise from ICIs, including the wash-out period before LT and post-LT immunosuppression adjustments, is crucial to balance the risk of graft rejection against HCC recurrence. Additionally, the effects of increased immunosuppression on non-hepatic complications must be understood to prevent them from becoming obstacles to long-term OS.

METHODS AND RESULTS

In this review, we will evaluate the emerging evidence and its implications for the future of LT in HCC. Addressing these novel challenges and opportunities, while integrating the current clinical evidence with predictive algorithms, would ensure a fair balance between individual patient needs and the overall population benefit in the LT system.

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

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.

AFP score and metroticket 2.0 perform similarly and could be used in a "within-ALL" clinical decision tool

BACKGROUND & AIMS

Two recently developed composite models, the alpha-fetoprotein (AFP) score and Metroticket 2.0, could be used to select patients with hepatocellular carcinoma (HCC) who are candidates for liver transplantation (LT). The aim of this study was to compare the predictive performance of both models and to evaluate the net risk reclassification of post-LT recurrence between them using each model's original thresholds.

METHODS

This multicenter cohort study included 2,444 adult patients who underwent LT for HCC in 47 centers from Europe and Latin America. A competing risk regression analysis estimating sub-distribution hazard ratios (SHRs) and 95% CIs for recurrence was used (Fine and Gray method). Harrell's adapted c-statistics were estimated. The net reclassification index for recurrence was compared based on each model's original thresholds.

RESULTS

During a median follow-up of 3.8 years, there were 310 recurrences and 496 competing events (20.3%). Both models predicted recurrence, HCC survival and survival better than Milan criteria (p <0.0001). At last tumor reassessment before LT, c-statistics did not significantly differ between the two composite models, either as original or threshold versions, for recurrence (0.72 vs. 0.68; p = 0.06), HCC survival, and overall survival after LT. We observed predictive gaps and overlaps between the model's thresholds, and no significant gain on reclassification. Patients meeting both models ("within-ALL") at last tumor reassessment presented the lowest 5-year cumulative incidence of HCC recurrence (7.7%; 95% CI 5.1-11.5) and higher 5-year post-LT survival (70.0%; 95% CI 64.9-74.6).

CONCLUSIONS

In this multicenter cohort, Metroticket 2.0 and the AFP score demonstrated a similar ability to predict HCC recurrence post-LT. The combination of these composite models might be a promising clinical approach.

IMPACT AND IMPLICATIONS

Composite models were recently proposed for the selection of liver transplant (LT) candidates among individuals with hepatocellular carcinoma (HCC). We found that both the AFP score and Metroticket 2.0 predicted post-LT HCC recurrence and survival better than Milan criteria; the Metroticket 2.0 did not result in better reclassification for transplant selection compared to the AFP score, with predictive gaps and overlaps between the two models; patients who met low-risk thresholds for both models had the lowest 5-year recurrence rate. We propose prospectively testing the combination of both models, to further optimize the LT selection process for candidates with HCC.

Liver transplantation for hepatocellular carcinoma: Historical evolution of transplantation criteria

Liver transplantation (LT) for hepatocellular carcinoma is still a hot topic, and the main factor that is associated with the success of treatment is to determine the patients who will benefit from LT. Milan criteria have been defined 25 years ago and still is being used for patient selection for LT. However, in living donor LT, the Milan criteria is being extended. Current criteria for patient selection do not only consider morphologic characteristics such as tumor size and number of tumor nodules but also biologic markers that show tumor aggressiveness is also being considered. In the present review article, we have summarized all the criteria and scoring systems regarding LT for hepatocellular carcinoma. All criteria have 5-year overall survival rates that were comparable to the Milan Criteria and ranged between 60%-85%. On the other hand, it was seen that the recurrence rates had increased as the Milan criteria were exceeded; the 5-year recurrence rates ranged between 4.9% to 39.9%. Treatment of hepatocellular carcinoma needs a multidisciplinary approach. Ideal selection criteria are yet to be discovered. The same is true for treatment modalities. The goal will be achieved by a harmonic interplay between basic science researchers and clinicians.

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.

Different Models to Predict the Risk of Recurrent Hepatocellular Carcinoma in the Setting of Liver Transplantation

Simple Summary

Liver transplantation is considered the first-choice curative therapy for hepatocellular carcinoma in the early phase of the disease, when surgical resection is not possible. Even when implementing restrictive criteria to select patients for liver transplantation, there is a risk of recurrence in the transplanted liver, influencing the long-term outcome and prognosis. As it is challenging to predict the individual risk of recurrence, there is a need for validated and predictive scoring systems to use to stratify patients before and/or after liver transplantation. Most of the proposed scorings include biological markers for tumour behavior, in addition to the number and size of tumoral nodules. In this review, we discuss different published models to assess the risk of recurrent hepatocellular carcinoma after transplantation. Our aim is to refine clinical decisions about prioritization and listing for liver transplantation, to better inform patients and provide an appropriate surveillance strategy to influence their prognosis.

Abstract

Liver transplantation is the preferred therapeutic option for non-resectable hepatocellular carcinoma in early-stage disease. Taking into account the limited number of donor organs, liver transplantation is restricted to candidates with long-term outcomes comparable to benign indications on the waiting list. Introducing the morphometric Milan criteria as the gold standard for transplant eligibility reduced the recurrence rate. Even with strict patient selection, there is a risk of recurrence of between 8 and 20% in the transplanted liver, and this is of even greater importance when using more expanded criteria and downstaging protocols. Currently, it remains challenging to predict the risk of recurrence and the related prognosis for individual patients. In this review, the recurrence-risk-assessment scores proposed in the literature are discussed. Currently there is no consensus on the optimal model or the implications of risk stratification in clinical practice. The most recent scorings include additional biological markers for tumour behavior, such as alfa-foetoprotein, and the response to locoregional therapies, in addition to the number and diameter of tumoral nodules. The refinement of the prediction of recurrence is important to better inform patients, guide decisions about prioritization and listing and implement individualized surveillance strategies. In the future, this might also provide indications for tailored immunosuppressive therapy or inclusion in trials for adjuvant treatment.

Risk stratification of patients with hepatocellular carcinoma undergoing trans arterial chemoembolization using an alpha-fetoprotein model

Background

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. There are multiple factors that could affect the malignancy and progression of HCC including tumor number, size, and macrovascular invasion. The alpha-fetoprotein (AFP) model was validated as a predictor for HCC recurrence post-liver transplantation, especially in France. However, the AFP model has not been studied on patients with HCC undergoing locoregional treatment. This study aimed to assess the prognostic value of the AFP model in patients with HCC undergoing trans arterial chemoembolization (TACE). This cohort study was conducted at Ain Shams University Hospitals, Cairo, Egypt. We included all newly diagnosed patients with HCC who were fit for TACE from January 2012 to January 2017. The AFP model was calculated for each patient before TACE. Subsequently, we classified them into low- and high-risk groups for TACE. The patients were followed up by AFP level and triphasic spiral CT performed 1 month after TACE to evaluate the response then at 4 months and 7 months post TACE to evaluate the local and distant recurrence.

Results

One hundred and thirty-two patients were included in the study. Complete response (CR) was achieved nonsignificantly at a higher percentage in the low-risk group in comparison with the high-risk group. One- and three-year recurrence-free survivals (RFS) were longer in the low-risk group in comparison with the high-risk group (50% and 24.1% vs. 29.1% and 16.2%, respectively). One- and three-year overall survival (OS) rates were 97% and 37.3% in the low-risk group vs. 98.1% and 11.6% in the high-risk group, respectively, without statistical significance. On classifying patients with AFP levels < 100 IU/mL into low- and high-risk patients, CR was achieved in a significantly higher percentage in the low-risk group in comparison with the high-risk group(P < 0.05). Recurrence occurred nonsignificantly in a less percentage in low than high-risk group. The median OS was significantly higher in the low-risk group in comparison with that in the high-risk group (18 vs. 16 months respectively) (P < 0.01).

Conclusion

The AFP model may have a prognostic value for patients with HCC undergoing TACE especially in patients with an AFP level < 100 IU/mL.

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.

Risk factors for poor survival after recurrence of hepatocellular carcinoma after liver transplantation

Purpose

This study was designed to analyze the risk factors for poor survival after recurrence of hepatocellular carcinoma after liver transplantation.

Methods

Patients who underwent liver transplantation for hepatocellular carcinoma during the period of 2007 to 2018 were reviewed and patients who experienced recurrence were included. Multivariable Cox proportional hazard ratios were performed for potential risk factors for survival after recurrence.

Results

A total of 151 recipients experienced hepatocellular carcinoma recurrence after liver transplantation. The median of the recurrence-free period was 9.3 months (0.89–97.25 months). The median follow-up after recurrence was 13.4 months (0.59–118.28 months). One-, 3-, and 5-year survival after recurrence were 65.2%, 34.0% and 20.5%, respectively. Multivariable Cox analysis showed that, graft from living donor (hazard ratio [HR], 0.430; 95% confidence interval [CI], 0.210–0.882; P = 0.021), recurrence-free interval of ≥9 months (HR, 0.257; 95% CI, 0.164–0.403; P < 0.001), alphafetoprotein of ≥100 ng/mL at the time of recurrence (HR, 1.689; 95% CI, 1.059–2.695; P = 0.028), and recurrence in bone (HR, 2.304; 95% CI, 1.399–3.794; P = 0.001) and everolimus within 3 months after recurrence (HR, 0.354; 95% CI, 0.141–0.889; P = 0.027) were related to survival after recurrence.

Conclusion

Although survival was generally poor after recurrence of hepatocellular carcinoma in liver transplantation recipients, prolonged survival can be achieved in certain patients with better prognostic factors.

Impact of Graft Weight Change During Perfusion on Hepatocellular Carcinoma Recurrence After Living Donor Liver Transplantation

BACKGROUNDS

Inadequate liver volume and weight is a major source of morbidity and mortality after adult living donor liver transplantation (LDLT). The purpose of our study was to investigate HCC recurrence, graft failure, and patient survival according to change in right liver graft weight after histidine-tryptophan-ketoglutarate (HTK) solution perfusion in LDLT.

METHODS

Two hundred twenty-eight patients underwent LDLT between 2013 and 2017. We calculated the change in graft weight by subtracting pre-perfusion graft weight from post-perfusion graft weight. Patients with increased graft weight were defined as the positive group, and patients with decreased graft weight were defined as the negative group.

RESULTS

After excluding patients who did not meet study criteria, 148 patients underwent right or extended right hepatectomy. The negative group included 89 patients (60.1%), and the positive group included 59 patients (39.9%). Median graft weight change was -28 g (range; -132-0 g) in the negative group and 21 g (range; 1-63 g) in the positive group (P<0.001). Median hospitalization time was longer for the positive group than the negative group (27 days vs. 23 days; P=0.048). There were no statistical differences in tumor characteristics, postoperative complications, early allograft dysfunction, or acute rejection between the two groups. Disease-free survival, death-censored graft survival, and patient survival were lower in the positive group than the negative group. Additionally, the positive group showed strong association with HCC recurrence, death-censored graft survival, and patient survival in multivariate analysis.

CONCLUSION

This study suggests that positive graft weight change during HTK solution perfusion indicates poor prognosis in LDLT.

Venous outflow congestion is related to poor recurrence-free survival of living donor liver transplantation recipients with hepatocellular carcinoma - a retrospective study

This study analyzed the impact of venous outflow congestion in the liver graft on hepatocellular carcinoma recurrence in liver transplantation recipients. Hepatocellular carcinoma patients who underwent living donor liver transplantation at Samsung Medical Center between 2007 and 2018 were included. The congested volume was calculated based on 2-week post-transplantation computed tomography. Recurrence-free survival and overall survival were analyzed using the multivariable Cox proportional hazard model including the degree of venous congestion. A total of 582 patients were included. There were 232 patients (39.9%) with certain degree of congestion volume. Kaplan-Meier survival analyses showed 1-, 5-, and 10-year recurrence-free survivals of 86.0%, 72.2%, and 70.7%, respectively, and overall survivals of 91.5%, 73.4%, and 68.9%, respectively. While congestion volume per 10 cm³ was a significant risk factor for recurrence-free survival (HR = 1.024, CI: 1.002-1.047, P = 0.034), there was no significant relationship with overall survival. (HR = 1.015, CI: 0.992-1.039, P = 0.213). Venous outflow congestion in the liver after living donor liver transplantation was related to the poor recurrence-free survival of hepatocellular carcinoma patients.

A 2020 update on liver transplant for hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma is the most frequent liver tumor and is associated with chronic liver disease in 90% of cases. In selected cases, liver transplantation represents an effective therapy with excellent overall survival.

AREA COVERED

Since the introduction of Milan criteria in 1996, numerous alternative selection systems to LT for HCC patients have been proposed. Debate remains about how best to select HCC patients for transplant and how to prioritize them on the waiting list.

EXPERT OPINION

The selection of the best scoring system to propose in the context of LT for HCC is far to be identified. In this review, we analyze and categorize the various selection systems, assessing their roles in the different decisional phases.

Argentinian clinical practice guideline for surveillance, diagnosis, staging and treatment of hepatocellular carcinoma

The A.A.E.E.H has developed this guideline for the best care of patients with hepatocellular carcinoma (HCC) from Argentina. It was done from May 2018 to March 2020. Specific clinical research questions were systematically searched. The quality of evidence and level of recommendations were organized according to GRADE. HCC surveillance is strongly recommended with abdominal ultrasound (US) every six months in the population at risk for HCC (cirrhosis, hepatitis B or hepatitis C); it is suggested to add alpha-feto protein (AFP) levels in case of inexeperienced sonographers. Imaging diagnosis in patients at risk for HCC has high specificity and tumor biopsy is not mandatory. The Barcelona Clinic Liver Cancer algorithm is strongly recommended for HCC staging and treatment-decision processes. Liver resection is strongly recommended for patients without portal hypertension and preserved liver function. Composite models are suggested for liver transplant selection criteria. Therapies for HCC with robust clinical evidence include transarterial chemoembolization (TACE) and first to second line systemic treatment options (sorafenib, lenvatinib, regorafenib, cabozantinib and ramucirumab). Immunotherapy with nivolumab and pembrolizumab has failed to show statistical benefit but the novel combination of atezolizumab plus bevacizumab has recently shown survival benefit over sorafenib in frontline.

Shadows Behind Using Simple Risk Models in Selection of Hepatocellular Carcinoma Patients for Liver Transplantation

OBJECTIVE

To assess the potential influence of replacing Milan criteria with simple risk scores on outcomes of hepatocellular carcinoma (HCC) patients undergoing liver transplantation.

SUMMARY BACKGROUND DATA

Several risk scores combining morphological and biological features were recently proposed for precise selection of HCC patients for transplantation.

METHODS

This retrospective study included 282 HCC liver transplant recipients. Recurrence-free survival (RFS), the primary outcome measure, was evaluated according to Metroticket 2.0 model and French AFP model with Milan criteria serving as benchmark.

RESULTS

Patients were well stratified with respect to RFS by Milan criteria, Metroticket 2.0 criteria, and AFP model cut-off ≤2 points (all P < 0.001) with c-statistics of 0.680, 0.695, and 0.681, respectively. Neither Metroticket 2.0 criteria (0.014, Z = 0.023; P = 0.509) nor AFP model (-0.014, Z = -0.021; P = 0.492) provided significant net reclassification improvement. Both patients within the Metroticket 2.0 criteria and AFP model ≤2 points exhibited heterogeneous recurrence risk, dependent upon alpha-fetoprotein (P = 0.026) and tumor number (P = 0.024), respectively. RFS of patients beyond Milan but within Metroticket 2.0 criteria (75.3%) or with AFP model ≤2 points (74.1%) was inferior to that observed for patients within Milan criteria (87.1%; P = 0.067 and P = 0.045, respectively). Corresponding microvascular invasion rates were 37.2% and 50.0%, compared with 13.6% in patients within Milan criteria (both P < 0.001). Moreover, Milan-out status was associated with significantly higher recurrence risk in subgroups within Metroticket 2.0 criteria (P = 0.021) or AFP model ≤2 points (P = 0.014).

CONCLUSION

Utilization of simple risk scores for liver transplant eligibility assessment leads to selection of patients at higher risk of posttransplant HCC recurrence.

Systematic review: risk prediction models for recurrence of hepatocellular carcinoma after liver transplantation

Recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) is a significant clinical problem associated with poor surgical outcomes. This study aims to summarize the current evidence on risk prediction models of HCC recurrence after LT. PubMed and EMBASE were searched to May 25, 2019, for relevant articles. Studies originally designed to develop or validate a risk prediction model for HCC recurrence after LT were included. Two independent authors summarized the study characteristics and evaluated the risk of bias and applicability concerns in the included studies. From 26 included studies, 18 original risk prediction models were determined, but only five models were externally validated. The average number of predictors involved in the construction of risk models was three. The most frequently employed predictors were alpha-fetoprotein, tumor size, vascular invasion, tumor number, tumor differentiation, and neutrophil-lymphocyte ratio. Most studies showed good discriminatory performance (AUC >0.75). The overall quality of the included studies was generally low. Most of the original models lacked the highly recommended external and prospective validation in diverse populations. The AFP model was the well-validated preoperative risk model that can stratify patients into high- and low-risk groups.

Is It Time to Reconsider the Milan Criteria for Selecting Patients With Hepatocellular Carcinoma for Deceased-Donor Liver Transplantation?

Liver transplantation (LT) is considered the optimal treatment for hepatocellular carcinoma (HCC) because it removes tumor as well as the underlying cirrhotic liver. Because of a global organ shortage, LT for patients with HCC is limited to patients with expected survival comparable to that of nonmalignant indications. Therefore, identifying patients with lower rates of HCC recurrence and higher rates of survival is critical. International guidelines have considered the Milan Criteria (MC) the standard for selecting patients with HCC for deceased-donor LT (DDLT). However, several alternative criteria have been reported in the Western world. Interestingly, the two most recent models combining α-fetoprotein level, number of nodules, and size of the largest nodule have been shown to outperform MC in identifying patients with low risk of HCC recurrence or those who will survive for 5 years after liver transplantation. In addition, new models overcome limitations of MC in improving classification of high- versus low-risk patients with HCC for DDLT. These recent scoring systems also provide clinicians with user-friendly tools to better identify patients at lower risk of recurrence. Conclusion: Although most Western countries still select patients based on MC, there is a mounting change in recent practice patterns regarding the selection of patients with HCC for DDLT. Herein, we describe how alternative criteria should lead to reconsideration of MC as it applies to selecting patients with HCC for DDLT in international guidelines.

Serum biomarkers and risk of hepatocellular carcinoma recurrence after liver transplantation

Liver transplantation (LT) is the only potentially curative treatment for selected patients with cirrhosis and hepatocellular carcinoma (HCC) who are not candidates for resection. When the Milan criteria are strictly applied, 75% to 85%of 3- to 4-year actuarial survival rates are achieved, but up to 20% of the patients experience HCC recurrence after transplantation. The Milan criteria are based on the preoperative tumor macromorphology, tumor size and number on computed tomography or magnetic resonance imaging that neither correlate well with posttransplant histological study of the liver explant nor accurately predict HCC recurrence after LT, since they do not include objective measures of tumor biology. Preoperative biological markers, including alpha-fetoprotein, des-gamma-carboxiprothrombin or neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio, can predict the risk for HCC recurrence after transplantation. These biomarkers have been proposed as surrogate markers of tumor differentiation and vascular invasion, with varied risk magnitudes depending on the defined cutoffs. Different studies have shown that the combination of one or several biomarkers integrated into prognostic models predict the risk of HCC recurrence after LT more accurately than Milan criteria alone. In this review, we focus on the potential utility of these serum biological markers to improve the performance of Milan criteria to identify patients at high risk of tumoral recurrence after LT.