Liver Transplantation for Hepatocellular Carcinoma after Downstaging or Bridging Therapy with Immune Checkpoint Inhibitors

Expanding Indications for Liver Transplantation in the Treatment of Hepatocellular Carcinoma

Improvements in downstaging therapies have expanded the indications for liver transplantation (LT) for hepatocellular carcinoma (HCC). Patients with more advanced disease are now considered candidates due to advancements in radiation therapy, combination therapies, and immunotherapy. Combination stereotactic body radiation therapy (SBRT) and trans-arterial chemoembolization (TACE) has been shown to be superior to the historic treatment, sorafenib, in patients with macrovascular invasion. These patients are now candidates for LT with stable disease after LRT. Patients with ruptured HCC and prolonged stability have also been shown to have acceptable outcomes. The role of neoadjuvant immunotherapy needs to be further defined and has the potential to further improve tumor control prior to transplant.

Impact of pre-transplant immune checkpoint inhibitor use on post-transplant outcomes in HCC: A systematic review and individual patient data meta-analysis

BACKGROUND AND AIM

Treatment with immune checkpoint inhibitors (ICIs) for hepatocellular carcinoma (HCC) prior to liver transplantation (LT) has been reported; however, ICIs may elevate the risk of allograft rejection and impact other clinical outcomes. This study aims to summarize the impact of ICI use on post-LT outcomes.

MATERIALS AND METHODS

In this individual patient data meta-analysis, we searched databases to identify HCC cases treated with ICIs before LT, detailing allograft rejection, HCC recurrence, and overall survival. We performed Cox regression analysis to identify risk factors for allograft rejection.

RESULTS

Among 91 eligible patients, with a median (interquartile range [IQR]) follow-up of 690.0 (654.5) days, there were 24 (26.4%) allograft rejections, 9 (9.9%) HCC recurrences, and 9 (9.9%) deaths. Age (adjusted hazard ratio [aHR] per 10 years=0.72, 95% confidence interval [CI]=0.53, 0.99, P=0.044) and ICI washout time (aHR per 1 week=0.92, 95% CI=0.86, 0.99, P=0.022) were associated with allograft rejection. The median (IQR) washout period for patients with ≤20% probability of allograft rejection was 94 (196) days. Overall survival did not differ between cases with and without allograft rejection (log-rank test, p=0.2). Individuals with HCC recurrence had fewer median (IQR) ICI cycles than those without recurrence (4.0 [1.8]) vs. 8.0 [9.0]); p=0.025). The proportion of patients within Milan post-ICI was lower for those with recurrence vs. without (16.7% vs. 65.3%, p=0.032) CONCLUSION: Patients have acceptable post-LT outcomes after ICI therapy. Age and ICI washout length relate to the allograft rejection risk, and a 3-month washout may reduce it to that of patients without ICI exposure. Number of ICI cycles and tumor burden may affect recurrence risk. Large prospective studies are necessary to confirm these associations.

IMPACT AND IMPLICATIONS

This systematic review and individual patient data meta-analysis of 91 patients with hepatocellular carcinoma and immune checkpoint inhibitors use prior to liver transplantation suggests acceptable overall post-transplant outcomes. Older age and longer immune checkpoint inhibitor washout period have a significant inverse association with the risk of allograft rejection. A 3-month washout may reduce it to that of patients without ICI exposure. Additionally, a higher number of immune checkpoint inhibitor cycles and tumor burden within Milan criteria at the completion of immunotherapy may predict a decreased risk of hepatocellular carcinoma recurrence, but this observation requires further validation in larger prospective studies. CODE FOR INTERNATIONAL PROSPECTIVE REGISTER OF SYSTEMATIC REVIEWS (PROSPERO): CRD42023494951.

Downstaging of Hepatocellular Carcinoma Before Liver Transplantation: Current Advances in Selection Criteria and Therapeutic Options

Liver transplantation (LT) is an ideal therapeutic option for selected patients with hepatocellular carcinoma (HCC). The selection criteria of HCC for LT have evolved in recent decades. Downstaging therapy is a promising strategy for patients with tumor burden beyond transplant criteria to increase the chance of receiving LT and improve posttransplant survival. Downstaging therapy is also a selection tool that refines the conventional selection criteria based on tumor morphology. Recently, the success of systemic treatment, including immune checkpoint inhibitors, antiangiogenic tyrosine kinase inhibitors, and VEGF inhibitors, in advanced HCC has prompted the discussion regarding the role of systemic therapies for HCC downstaging before transplantation. In this review, we aimed to summarize the current advances in selection criteria and therapeutic options of downstaging therapy for HCC before LT.

Hepatocellular Carcinoma: The Evolving Role of Systemic Therapies as a Bridging Treatment to Liver Transplantation

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related deaths. Classically, liver transplantation (LT) can be curative for HCC tumors within the Milan criteria. Bridging strategies to reduce the dropouts from LT waiting lists and/or to downstage patients who are beyond the Milan criteria are widely utilized. We conducted a literature-based review to evaluate the role of systemic therapies as a bridging treatment to liver transplantation (LT) in HCC patients. Tyrosine kinase inhibitors (TKIs) can be used as a systemic bridging therapy to LT in patients with contraindications for locoregional liver-directed therapies. Immune checkpoint inhibitor (ICI) treatment can be utilized either as a monotherapy or as a combination therapy with bevacizumab or TKIs prior to LT. Acute rejection after liver transplantation is a concern in the context of ICI treatment. Thus, a safe ICI washout period before LT and cautious post-LT immunosuppression strategies are required to reduce post-LT rejections and to optimize clinical outcomes. Nevertheless, prospective clinical trials are needed to establish definitive conclusions about the utility of systemic therapy as a bridging modality prior to LT in HCC patients.

Geographic disparities in access to liver transplant for advanced cirrhosis: Time to ring the alarm!

Decompensated cirrhosis and hepatocellular cancer are major risk factors for mortality worldwide. Liver transplantation (LT), both live-donor LT or deceased-donor LT, are lifesaving, but there are several barriers toward equitable access. These barriers are exacerbated in the setting of critical illness or acute-on-chronic liver failure. Rates of LT vary widely worldwide but are lowest in lower-income countries owing to lack of resources, infrastructure, late disease presentation, and limited donor awareness. A recent experience by the Chronic Liver Disease Evolution and Registry for Events and Decompensation consortium defined these barriers toward LT as critical in determining overall survival in hospitalized cirrhosis patients. A major focus should be on appropriate, affordable, and early cirrhosis and hepatocellular cancer care to prevent the need for LT. Live-donor LT is predominant across Asian countries, whereas deceased-donor LT is more common in Western countries; both approaches have unique challenges that add to the access disparities. There are many challenges toward equitable access but uniform definitions of acute-on-chronic liver failure, improving transplant expertise, enhancing availability of resources and encouraging knowledge between centers, and preventing disease progression are critical to reduce LT disparities.

Liver Transplantation for Hepatocellular Carcinoma beyond the Milan Criteria: A Specific Role for Living Donor Liver Transplantation after Neoadjuvant Therapy

PURPOSE

This study was designed to elucidate the various new classifications and the use of LDLT and bridging therapy for HCC in this context beyond the Milan criteria (MC).

METHODS

The clinical data of patients with HCC outside the MC who underwent LT at Jena University between January 2007 and August 2023 were retrospectively analysed. Eligible patients were classified according to various classification systems. Clinicopathological features, overall and disease-free survival rates were compared between LT and LDLT within the context of bridging therapy.

THE RESULTS

Among the 245 patients analysed, 120 patients did not meet the MC, and 125 patients met the MC. Moreover, there were comparable overall survival rates between patients outside the MC for LT versus LDLT (OS 44.3 months vs. 28.3 months; 5-year survival, 56.4% vs. 40%; p = 0.84). G3 tumour differentiation, the presence of angioinvasion and lack of bridging were statistically significant risk factors for tumour recurrence according to univariate and multivariate analyses (HR 6.34; p = 0.0002; HR 8.21; p < 0.0001; HR 7.50; p = 0.0001). Bridging therapy before transplantation provided a significant survival advantage regardless of the transplant procedure (OS: p = 0.008; DFS: p < 0.001).

CONCLUSIONS

Patients with HCC outside the MC who underwent LT or LDLT had worse outcomes compared to those of patients who met the MC but still had a survival advantage compared to patients without transplantation. Nevertheless, such patients remain disadvantaged on the waiting list, which is why LDLT represents a safe alternative to LT and should be considered in bridged HCC patients because of differences in tumour differentiation, size and tumour marker dynamics.

Transplant oncology - Current indications and strategies to advance the field

Liver transplantation (LT) was originally described by Starzl as a promising strategy to treat primary malignancies of the liver. Confronted with high recurrence rates, indications drifted towards non-oncologic liver diseases with LT finally evolving from a high-risk surgery to an almost routine surgical procedure. Continuously improving outcomes following LT and evolving oncological treatment strategies have driven renewed interest in transplant oncology. This is not only reflected by constant refinements to the criteria for LT in patients with HCC, but especially by efforts to expand indications to other primary and secondary liver malignancies. With new patient-centred oncological treatments on the rise and new technologies to expand the donor pool, the field has the chance to come full circle. In this review, we focus on the concept of transplant oncology, current indications, as well as technical and ethical aspects in the context of donor organs as precious resources.

Immunotherapy before liver transplant in unresectable hepatocellular carcinoma: a case report

Background

Hepatocellular carcinoma (HCC) is a leading cause of global cancer mortality, with liver transplantation as the sole curative treatment. For advanced disease, first-line systemic therapies including immune checkpoint inhibitors (ICIs) have shown a survival benefit, but there is scarce data on clinical outcomes when used prior to transplantation.

Case Description

We present three case studies of patients who received immunotherapy with atezolizumab/bevacizumab or ipilimumab/nivolumab before liver transplant. We reviewed clinical outcomes including disease response, adverse events related to systemic therapy, as well as graft function post-operatively. One case demonstrated a 45% reduction in total HCC tumour burden whereas another showed stable disease with ICIs. No adverse clinical outcomes such as graft rejection or poor wound healing were noted post-transplant. Indeed, all three patients were successfully transplanted with excellent graft function at the last follow-up.

Conclusions

Our observations and data suggest ICIs are a viable option for treatment in the pre-transplant setting. It does not routinely lead to fatal graft rejection and may lengthen eligibility times until a donor organ is available.

Evidence to Date: Clinical Utility of Tremelimumab in the Treatment of Unresectable Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide and is associated with significant health care costs and burden. Management of HCC is guided based on the Barcelona Clinic Liver Cancer (BCLC) system and includes liver transplantation, surgical resection, and liver-directed and systemic therapies. In recent years, there have been significant advancements in understanding the immunogenicity of HCC and this has led to approval of different targeted agents as well as immunotherapy for advanced HCC. Tremelimumab is a cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) blocking antibody and has recently been approved in combination with durvalumab (a programmed death-ligand 1 [PDL1] inhibitor) as first-line therapy for advanced (Barcelona Clinic Liver Cancer Stage C) HCC. In this article, we review the different available systemic therapies for advanced HCC with special focus on the clinical utility of tremelimumab for the treatment of unresectable HCC.

Hepatocellular Carcinoma: The Role of Immunotherapy and Transplantation in the Era of Transplant Oncology

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer deaths worldwide. As most patients present with advanced disease, curative therapy such as surgical resection and radiofrequency ablation are rarely utilized. With the advent of immunotherapy, historical treatment approaches such as liver transplantation are being challenged. In particular, the use of immune checkpoint inhibitors (ICIs) has emerged as a safe and useful option in the treatment of HCC. However, there is concern over adverse effects, such as graft rejection and graft loss. This updated review discusses the role of immunotherapy in the pre- and post-transplantation setting and provides insights into the potential of immunotherapy as an adjunct to liver transplantation. We deliberate on the use of ICI in the setting of the Milan criteria as well as the University of California San Francisco's expanded criteria for liver transplantation. Current data suggest that ICI has utility, especially in the pretransplantation setting. Nevertheless, larger, purposefully designed clinical trials are needed to clearly identify patients who will benefit most from ICI treatment in the transplant setting and determine parameters that will minimize the risk of graft rejection and maximize the benefits of this adjunct treatment.

Immunotherapy and Liver Transplantation: A Narrative Review of Basic and Clinical Data

Immune checkpoint inhibitors (ICIs) have improved the management of patients with intermediate- and advanced-stage HCC, even making some of them potential candidates for liver transplantation. However, acute rejection has been observed after ICI therapy, challenging its safety in transplant settings. We summarize the key basic impact of immune checkpoints on HCC and liver transplantation. We analyze the available case reports and case series on the use of ICI therapy prior to and after liver transplantation. A three-month washout period is desirable between ICI therapy and liver transplantation to reduce the risk of acute rejection. Whenever possible, ICIs should be avoided after liver transplantation, and especially so early after a transplant. Globally, more robust prospective data in the field are required.

Trial watch: immunotherapeutic strategies on the horizon for hepatocellular carcinoma

The use of immune checkpoint inhibitors (ICIs) targeting PD-L1/PD-1 and CTLA-4 has transformed the oncology practice of hepatocellular carcinoma. However, only 25-30% of the patients with advanced HCC treated with atezolizumab-bevacizumab or tremelimumab-durvalumab (STRIDE) respond initially, and mechanistic biomarkers and novel treatment strategies are urgently needed for patients who present with or acquire resistance to first-line ICI-based therapies. The recent approval of the STRIDE regimen has also engendered new questions, such as patient selection factors (e.g. portal hypertension and history of variceal bleed) and biomarkers, and the optimal combination and sequencing of ICI-based regimens. Triumphs in the setting of advanced HCC have also galvanized considerable interest in the broader application of ICIs to early- and intermediate-stage diseases, including clinical combination of ICIs with locoregional therapies. Among these clinical contexts, the role of ICIs in liver transplantation - which is a potentially curative strategy unique to HCC management - as a bridge to liver transplant in potential candidates or in the setting of post-transplant recurrence, warrants investigation in view of the notable theoretical risk of allograft rejection. In this review, we summarize and chart the landscape of seminal immuno-oncology trials in HCC and envision future clinical developments.

Proceedings of the 27th Annual Congress of the International Liver Transplantation Society

After a virtual congress in 2021 and a previous absence in 2020 because of the coronavirus disease 2019 pandemic, the 27th Annual Congress of the International Liver Transplantation Society was held from May 4 to 7, 2022, in a hybrid format in Istanbul, with 1123 (58% on-site) liver transplant professionals from 61 countries attending the meeting. The hybrid format successfully achieved a balance of much yearned-for "in-person interaction" and global online participation. Almost 500 scientific abstracts were presented. In this report, the Vanguard Committee aims to present a summary of key invited lectures and selected abstracts for the liver transplant community.

The Additive Value of Radiomics Features Extracted from Baseline MR Images to the Barcelona Clinic Liver Cancer (BCLC) Staging System in Predicting Transplant-Free Survival in Patients with Hepatocellular Carcinoma: A Single-Center Retrospective Analysis

BACKGROUND

To study the additive value of radiomics features to the BCLC staging system in clustering HCC patients.

METHODS

A total of 266 patients with HCC were included in this retrospective study. All patients had undergone baseline MR imaging, and 95 radiomics features were extracted from 3D segmentations representative of lesions on the venous phase and apparent diffusion coefficient maps. A random forest algorithm was utilized to extract the most relevant features to transplant-free survival. The selected features were used alongside BCLC staging to construct Kaplan-Meier curves.

RESULTS

Out of 95 extracted features, the three most relevant features were incorporated into random forest classifiers. The Integrated Brier score of the prediction error curve was 0.135, 0.072, and 0.048 for the BCLC, radiomics, and combined models, respectively. The mean area under the receiver operating curve (ROC curve) over time for the three models was 81.1%, 77.3%, and 56.2% for the combined radiomics and BCLC models, respectively.

CONCLUSIONS

Radiomics features outperformed the BCLC staging system in determining prognosis in HCC patients. The addition of a radiomics classifier increased the classification capability of the BCLC model. Texture analysis features could be considered as possible biomarkers in predicting transplant-free survival in HCC patients.

Adjuvant ICIs Plus Targeted Therapies Reduce HCC Recurrence after Hepatectomy in Patients with High Risk of Recurrence

BACKGROUND

The high recurrence rate of hepatocellular carcinoma (HCC) after hepatectomy usually results in poor prognosis. To the best of our knowledge, no study has reported the efficacy of immune checkpoint inhibitors (ICIs) plus targeted therapies on preventing HCC recurrence after hepatectomy. Thus, the aim of this study was to investigate the benefits and safety of applying adjuvant ICIs plus targeted therapies after hepatectomy for patients at high risk of HCC recurrence.

METHODS

A total of 196 patients with any risk factors for recurrence who underwent hepatectomy for HCC were reviewed in this retrospective study.

RESULTS

Compared with the control group (n = 158), ICIs plus targeted therapies (n = 38) had a significantly higher recurrence-free survival (RFS) rate in univariate analysis (HR, 0.46; 95% confidence interval [CI], 0.24-0.90; p = 0.020), multivariate analysis (adjusted HR, 0.62; 95%CI, 0.49-0.79; p < 0.001) and propensity score-matched analysis (HR, 0.35; 95%CI, 0.16-0.75; p = 0.005). Subgroup analyses also showed that postoperative adjuvant ICIs plus targeted therapies might reduce HCC recurrence in patients with the most of risk factors.

CONCLUSION

Postoperative adjuvant ICI plus targeted therapies may reduces early HCC recurrence in patients with a high risk of recurrence, and the treatments are well tolerated.

Immunotherapy for Hepatocellular Carcinoma in the Setting of Liver Transplantation: A Review

The emerging field of immuno-oncology has brought exciting developments in the treatment of hepatocellular carcinoma (HCC). It has also raised urgent questions about the role of immunotherapy in the setting of liver transplantation, both before and after transplant. A growing body of evidence points to the safety and efficacy of immunotherapeutic agents as potential adjuncts for successful down-staging of advanced HCCs to allow successful transplant in carefully selected patients. For patients with recurrent HCC post-transplant, immunotherapy has a limited, yet growing role. In this review, we describe optimal regimens in the setting of liver transplantation.

Current status of liver transplantation for non-B non-C liver cirrhosis and hepatocellular carcinoma

Recently, non-B non-C chronic liver diseases, including alcoholic liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH), have markedly increased worldwide. Liver transplantation (LT) is an effective curative therapy for hepatocellular carcinoma (HCC) as well as decompensated liver cirrhosis. In Japan, where the source of liver grafts is strongly dependent on living donors, efforts have been made to unify the indications for eligibility of HCC patients for LT, leading to the development of 5-5-500 criteria. Along with the expansion of eligibility for LT, the current changing trends in underlying liver diseases of LT recipients, which are related to the rising tide of non-B non-C cirrhosis and HCC, are highlighting the importance of peri-transplant management of patients with various comorbidities. The post-LT prognosis of patients with ALD is significantly affected by de novo malignancies and metabolic syndrome-related complications as well as posttransplant alcohol relapse. NAFLD/NASH patients often suffer from obesity, type 2 diabetes mellitus, and other metabolic syndrome-related disorders, and nonneoplastic factors such as cardiovascular events and recurrence of NAFLD/NASH have a significant impact on post-LT outcomes. Patient management in the peri-transplant period as well as risk assessment for LT are key to improving post-LT outcomes in the era of a growing number of cases of LT for non-B non-C liver diseases.

Immunotherapy Use Prior to Liver Transplant in Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related mortality worldwide, and its incidence has increased rapidly in the United States over the past two decades. Liver transplant is considered curative, but is not always possible, and pre-transplant immunotherapy is of great interest as a modality for downstaging the tumor burden. We present a review of the literature on pre-liver transplant immunotherapy use in patients with HCC. Our literature search queried publications in Ovid MEDLINE, Ovid Embase, and Web of Science, and ultimately identified 24 original research publications to be included for analysis. We found that the role of PD-1 and PD-L1 in risk stratification for rejection is of special interest to researchers, and ongoing randomized clinical trials PLENTY and Dulect 2020-1 will provide insight into the role of PD-1 and PD-L1 in liver transplant management in the future. This literature search and the resulting review represents the most thorough collection, analysis, and presentation of the literature on the subject to date.

Role of immunotherapy in downsizing hepatocellular carcinoma prior to liver transplantation

Hepatocellular carcinoma (HCC) is an aggressive primary liver neoplasm that, according to tumor stage, can be treated with resection, transplantation, locoregional treatment options, or systemic therapy. Although interventions only in early-stage disease can offer complete tumor regression, systemic therapy in advanced disease can significantly prolong overall survival, according to published clinical trials. The emergence of immunotherapy in the field of cancer therapy has had a positive impact on patients with HCC, resulting in atezolizumab–bevacizumab currently being the first-line option for treatment of advanced HCC. In light of this, application of immunotherapy in the preoperative process could increase the number of patients fulfilling the criteria for liver transplantation (LT). Implementation of this approach is faced with challenges regarding the safety of immunotherapy and the possibly increased risk of rejection in the perioperative period. Case reports and clinical trials assessing the safety profile and effectiveness of neoadjuvant immunotherapy, highlight important aspects regarding this newly evolving approach to HCC management. More studies need to be conducted in order to reach a consensus regarding the optimal way to administer immunotherapy prior to LT. In this review, we summarize the role, safety profile and future considerations regarding the use of neoadjuvant immunotherapy prior to LT in patients with HCC.

G Protein Subunit Gamma 5 Is a Prognostic Biomarker and Correlated with Immune Infiltrates in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the malignancies with an extremely inferior prognosis in the abdominal cavity, making it essential to develop more effective biomarkers for HCC. Although GNG5 has been linked to increased patient survival in a variety of human malignancies, no evidence has been found for its involvement in the development of HCC yet. Our study first analyzed the expression and prognosis of GNG5 in HCC using The Cancer Genome Atlas database (TCGA database) with the Gene Expression Omnibus database (GEO database) and found that GNG5 has a potential oncogenic role. Based on survival analysis, the clinical importance and prognostic value of the GNG5 gene were studied. Relying on tumor Immune Estimation Resource database (TIMER database), we analyzed the correlation between the GNG5 gene and HCC Immune infiltration cells. GNG5 expression levels were significantly higher in HCC tissues compared to normal liver tissues. HCC patients with high GNG5 expression had significantly reduced overall survival time and affected multiple immune cell infiltrates. Additionally, KEGG functional enrichment analysis indicated the PI3K-Akt signaling pathway as the most promising carcinogenic pathway associated with GNG5. This is the first comprehensive revelation of GNG5 as a possible new biological marker associated with immune infiltration in HCC. Additionally, it holds promise as an emerging target for HCC immunotherapy.