Immune checkpoint inhibitors in malignancies after liver transplantation: A systematic review and pooled analysis

Latin American expert opinion letter on the feasibility of systemic therapies in combination with locoregional therapies for hepatocellular carcinoma

Recent advances in the systemic treatment of advanced hepatocellular carcinoma (HCC) with immunotherapy have once again reignited discussion over the role of combined therapy in earlier stages. This year, different international meetings have presented recent results from clinical trials on adjuvant therapy alone (IMBrave-050) and combined with transarterial chemoembolization (EMERALD-1 and LEAP-12). Increased enthusiasm for the use of adjuvant and neoadjuvant therapy for liver transplantation, surgery, and local-regional treatment of HCC has been shown. However, the initial results from these trials should be interpreted cautiously as we wait for final analyses and effects on overall survival. In this position paper from the special interest group from the Latin American Association for the Study of Liver Diseases (ALEH), we underline the caveats of the applicability of these potential treatments in our region, explore points of agreement, and highlight areas of uncertainty. Moreover, we underscore the role of hepatologists in the clinical decision-making process and management of these patients.

Renal metastasis of hepatocellular carcinoma after living donor liver transplantation

Introduction

We report a case of renal metastasis of hepatocellular carcinoma in a liver transplant recipient.

Case presentation

A 66-year-old man who was diagnosed with hepatocellular carcinoma and considered to be in complete remission for 7 years underwent living donor liver transplantation. A residual tumor was found in the removed native liver. Computed tomography at 13 months after transplantation revealed a 24-mm hypervascular tumor with arterial phase enhancement, venous phase washout in the right kidney, and increasing hepatocellular carcinoma tumor markers. Partial nephrectomy was performed and the renal tumor was diagnosed as renal metastasis of hepatocellular carcinoma. Tumor marker levels decreased temporarily, but pulmonary metastasis and pleural dissemination subsequently appeared.

Conclusion

Renal metastasis of hepatocellular carcinoma should be considered when renal tumors are detected in liver transplant recipients because the risks of tumor recurrence and metastasis are increased.

Surgical treatment for hepatocellular carcinoma in era of multidisciplinary strategies

Hepatocellular carcinoma (HCC) remains a significant global health challenge, with over 800,000 new cases diagnosed annually. This comprehensive review examines current surgical approaches and emerging multidisciplinary strategies in HCC treatment. While traditional surgical criteria, such as the Barcelona Clinic Liver Cancer (BCLC) staging system, have been relatively conservative, recent evidence from high-volume Asian centers supports more aggressive surgical approaches in carefully selected patients. The review discusses the evolution of selection criteria, including the new "Borderline Resectable HCC" classification system, which provides more explicit guidance for surgical decision-making. Technical innovations have significantly enhanced surgical precision, including three-dimensional simulation, intraoperative navigation systems, and the advancement of minimally invasive approaches. The review evaluates the ongoing debate between anatomical versus non-anatomical resection and examines the emerging role of robotic surgery. In liver transplantation, expanded criteria beyond the Milan criteria show promising outcomes, while the integration of novel biomarkers and imaging techniques improves patient selection. The role of preoperative and adjuvant therapies is increasingly important, with recent trials demonstrating the potential of immune checkpoint inhibitors combined with anti-VEGF agents in both settings. Despite these advances, postoperative recurrence remains a significant challenge. The review concludes that successful HCC treatment requires a personalized approach, integrating surgical expertise with emerging technologies and systemic therapies while considering individual patient factors and regional variations in practice patterns.

Immunosuppression protocols for emerging oncological indications in liver transplantation: A systematic review and pooled analysis

The evolving field of liver transplant (LT) oncology calls for tailored immunosuppression protocols to minimize the risk of tumor recurrence. We systematically reviewed the available evidence from inception to May 2023 regarding immunosuppression protocols used in patients undergoing LT for cholangiocarcinoma, neuroendocrine tumors (NET), hepatic-endothelial hemangioendothelioma, and colorectal liver metastases (CRLM) to identify common practices and to evaluate their association with oncological outcomes. Studies not involving humans, case reports, and short case series (ie, n < 10) were excluded. Among 3374 screened references, we included 117 studies involving 6797 patients distributed as follows: cholangiocarcinoma (58.1%), NETs (18.8%), hepatic-endothelial hemangioendothelioma (7.7%), CRLM (6.8%), mixed neoplasms (6.8%), or others (1.7%). Only 41% of the studies disclosed details of the immunosuppression protocol, and 20.8% of studies provided drug trough concentrations during follow-up. The immunosuppression protocols described were heterogeneous and broadly mirrored routine practices for nontumoral indications. The only exception was CRLM, where tacrolimus minimization-or even withdrawal-in combination with inhibitors of the mammalian target of rapamycin (mTORi) were consistently reported. None of the studies evaluated the relationship between the immunosuppression protocol and oncological outcomes. In conclusion, based on low-quality and indirect scientific evidence, patients with tumoral indications for LT should receive the lowest tacrolimus level tolerated under close surveillance. The combination with mTORi titrated to achieve the top therapeutic range of trough concentrations could allow complete tacrolimus withdrawal. This approach may be particularly useful in patients with cholangiocarcinoma and CRLM, in whom tumor recurrence is the main cause of death. We propose a tool for reporting immunosuppression protocols, which could be implemented in future transplant oncology studies.

EASL Clinical Practice Guidelines on the management of hepatocellular carcinoma

Liver cancer is the third leading cause of cancer-related deaths worldwide, with hepatocellular carcinoma (HCC) accounting for approximately 90% of primary liver cancers. Advances in diagnostic and therapeutic tools, along with improved understanding of their application, are transforming patient treatment. Integrating these innovations into clinical practice presents challenges and necessitates guidance. These clinical practice guidelines offer updated advice for managing patients with HCC and provide a comprehensive review of pertinent data. Key updates from the 2018 EASL guidelines include personalised surveillance based on individual risk assessment and the use of new tools, standardisation of liver imaging procedures and diagnostic criteria, use of minimally invasive surgery in complex cases together with updates on the integrated role of liver transplantation, transitions between surgical, locoregional, and systemic therapies, the role of radiation therapies, and the use of combination immunotherapies at various stages of disease. Above all, there is an absolute need for a multiparametric assessment of individual risks and benefits, considering the patient's perspective, by a multidisciplinary team encompassing various specialties.

Bibliometric and LDA analysis of acute rejection in liver transplantation: Emerging trends, immunotherapy challenges, and the role of artificial intelligence

With the rising demand for liver transplantation (LT), research on acute rejection (AR) has become increasingly diverse, yet no consensus has been reached. This study presents a bibliometric and latent Dirichlet allocation (LDA) topic modeling analysis of AR research in LT, encompassing 1399 articles. The United States, Zhejiang University, and the University of California, San Francisco emerged as leading contributors, while Levitsky J and Uemoto SJ were key researchers. The most influential journals included the American Journal of Transplantation, Journal of Hepatology, and Transplantation. The analysis reveals a transition from traditional histological assessments to molecular diagnostics, genetic and epigenetic profiling, and noninvasive biomarkers such as donor-derived cell-free DNA (dd-cfDNA) and microRNAs. Advances in immune checkpoint inhibitors (ICIs), cell-based therapies (Tregs, mesenchymal stem cells (MSCs)), AI-guided immunosuppression, and nanoparticle-mediated drug delivery systems reflect a growing emphasis on precision medicine. In addition, recent exploration of microbiome-based therapies and regenerative medicine, including MSCs and their extracellular vesicles, offers promising new avenues for reducing long-term immunosuppressive drug dependency and enhancing graft survival. These developments not only improve early AR detection and personalized treatment but also reduce toxicity, foster immune tolerance, and expand the scope of individualized therapeutic options. Global collaboration, supported by cutting-edge research and AI-driven decision-making, remains essential for refining AR strategies, improving graft survival, and achieving better long-term patient outcomes.

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

BACKGROUND & AIMS

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.

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 (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% 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 inhibitor use prior to liver transplantation suggest 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 immune checkpoint inhibitor 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.

Cirrhosis and complications hepatocellular carcinoma - expanding indications for immunotherapy

The incidence of hepatocellular carcinoma (HCC) is rising, with a shift towards Metabolic Dysfunction-associated Steatotic Liver Disease becoming the dominant risk factor in Western countries. Significant advances in treatment have broadened the range of available therapeutic options. For this reason, clinical decision-making, along with a multidisciplinary team approach, plays a crucial role in improving patient outcomes. Following several landmark trials, immune checkpoint inhibitor-based therapy has now become the established first-line standard of care for advanced HCC. Additionally, the application of immunotherapy is shifting to include patients with earlier stages of HCC. Research on the combination with locoregional therapies for intermediate-stage HCC has recently reported positive results, and other phase III trials in the same patient population and early-stage HCC are currently in progress. Furthermore, a growing number of reports support the safety and efficacy of immunotherapeutic agents as potential adjuncts for downstaging of HCC, thus facilitating successful liver transplantation. We will discuss the published and ongoing trials in the expanding field of immune checkpoint inhibitor-based therapy for different stages of HCC.

Pembrolizumab in combination with LEnvatinib in participants with hepatocellular carcinoma before liver transplant as Neoadjuvant TherapY-PLENTY pilot study

BACKGROUND

The high recurrent rate after liver transplantation (LT) remains a clinical challenge, especially for those exceeding the Milan criteria (MC) and with high RETREAT scores. Therefore, the authors aim to investigate whether neoadjuvant systemic therapy allows safely administered and effectively reduces post-LT recurrence for those patients.

METHODS

In this prospective, randomized, open-label, pilot study, patients with HCC exceeding the MC were randomly assigned to PLENTY or control group before LT. The primary endpoint of the study was the recurrence-free survival after LT.

RESULTS

Twenty-two patients were enrolled and randomly assigned: 11 to the PLENTY group and 11 to the control group. The 30-month tumor-specific RFS was 37.5% in the PLENTY group and 12.5% in the control group. The 12-month tumor-specific RFS after LT was significantly improved in the PLENTY group (87.5%) compared to the control group (37.5%) ( P =0·0022). The objective response rate in the PLENTY group was 30 and 60% when determined by RECIST 1.1 and mRECIST, respectively. Six patients (60%) had significant tumor necrosis, including three (30%) who had complete tumor necrosis at histopathology. No acute allograft rejection after LT occurred in the PLENTY and Control group.

CONCLUSION

Neoadjuvant pembrolizumab plus lenvatinib before LT appears to be safe and feasible, associated with significantly better RFS for patients exceeding the MC. Despite the limitations of small sample size, this is the first RCT to evaluate neoadjuvant PD-1 blockade combined with tyrosine kinase inhibitors in LT recipients, the results of this study will inform future research.

Rethinking Immune Check Point Inhibitors Use in Liver Transplantation: Implications and Resistance

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy, including the two most common liver tumors, hepatocellular carcinoma and cholangiocarcinoma, but their use in the peri-transplantation period is controversial. ICI therapy aims to heighten cytotoxic T lymphocytes response against tumors. However, tumor recurrence is common owing to tumor immune response escape involving ablation of CTL response by interfering with antigen presentation, triggering CLT apoptosis and inducing epigenetic changes that promote ICI therapy resistance. ICI can also affect tissue resident memory T cell population, impact tolerance in the post-transplant period, and induce acute inflammation risking graft survival post-transplant. Their interaction with immunosuppression may be key in reducing tumor burden and may thus, require multimodal therapy to treat these tumors. This review summarizes ICI use in the liver transplantation period, their impact on tolerance and resistance, and new potential therapies for combination or sequential treatments for liver tumors.

Challenges in Liver Transplantation for Hepatocellular Carcinoma: A Review of Current Controversies

Liver transplantation (LT) remains one of the most effective treatments for hepatocellular carcinoma (HCC) and significantly enhances patient survival. However, the application of LT for HCC faces challenges owing to advancements in cancer-specific treatment modalities and the increased burden of patients' comorbidities. This narrative review explores current controversies and advancements in LT for HCC. Key areas of focus include the management of comorbidities and patient education by advanced practice nurses, impacts of frailty on waitlists and post-LT outcomes, selection criteria for LT in the era of new downstaging tools, role of radiology in patient selection, and implications of potential immunotherapy use both before and after LT. Additionally, the importance of immunosuppression management with strategies aimed at minimizing rejection while considering the risk of HCC recurrence and the role of surveillance for HCC recurrence is highlighted. This review also underscores the importance of a multidisciplinary approach for optimizing outcomes in patients with HCC undergoing LT.

Management of long-term complications from immunosuppression

This review discusses long-term complications from immunosuppressants after liver transplantation and the management of these complications. Common complications of calcineurin inhibitors include nephrotoxicity and metabolic diseases. Nephrotoxicity can be managed by targeting a lower drug level and/or adding an immunosuppressant of a different class. Metabolic disorders can be managed by treating the underlying condition and targeting a lower drug level. Gastrointestinal adverse effects and myelosuppression are common complications of antimetabolites that are initially managed with dose reduction or discontinuation if adverse events persist. Mammalian targets of rapamycin inhibitors are associated with myelosuppression, proteinuria, impaired wound healing, and stomatitis, which may require dose reduction or discontinuation. Induction agents and agents used for steroid-refractory rejection or antibody-mediated rejection are reviewed. Other rare complications of immunosuppressants are discussed as well.

Pushing the limits of treatment for hepatocellular carcinoma

PURPOSE OF REVIEW

We review existing and newer strategies for treatment and surveillance of hepatocellular carcinoma (HCC) both pre and postliver transplantation.

SUMMARY

HCC is rising in incidence and patients are often diagnosed at later stages. Consequently, there is a need for treatment strategies which include collaboration of multiple specialties. Combinations of locoregional, systemic, and surgical therapies are yielding better postliver transplantation (post-LT) outcomes for patients with HCC than previously seen. Tumor biology (tumor size, number, location, serum markers, response to therapy) can help identify patients who are at high risk for HCC recurrence posttransplantation and may expand transplant eligibility for some patients.

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 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.

New Opportunities to Individualize Frontline Therapy in Advanced Stages of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer death globally and is rising in incidence. Until recently, treatment options for patients with advanced stages of HCC have been limited to antiangiogenic therapies with modest improvements in overall survival. The emerging role of immunotherapy with immune checkpoint inhibitors (ICI) in oncology has led to a rapid expansion in treatment options and improvements in outcomes for patients with advanced stages of HCC. Recent clinical trials have shown meaningful survival improvement in patients treated with the combination of bevacizumab and atezolizumab, as well as with the combination of tremelimumab with durvalumab, resulting in regulatory approvals of these regimens as frontline therapy. Beyond improvements in overall survival, ICI-based combination regimens achieve higher rates of durable treatment response than multikinase inhibitors and have favorable side effect profiles. With the emergence of doublet anti-angiogenic and immune checkpoint inhibitor (ICI) and dual ICI combinations, individualized therapy is now possible for patients based on co-morbidity profiles and other factors. These more potent systemic therapies are also being tested in earlier stages of disease and in combination with loco-regional therapies such as trans-arterial chemoembolization and stereotactic body radiotherapy. We summarize these advances and emerging therapeutic combinations currently in clinical trials.