Harnessing immunotherapy for liver recipients with hepatocellular carcinoma: a review from a transplant oncology perspective

Advanced therapeutics avenues in hepatocellular carcinoma: a novel paradigm

Hepatocellular carcinoma (HCC) is the most frequent type of primary liver cancer, and it poses a significant risk to patients health and longevity due to its high morbidity and fatality rates. Surgical ablation, radiotherapy, chemotherapy, and, most recently, immunotherapy have all been investigated for HCC, but none have yielded the desired outcomes. Several unique nanocarrier drug delivery techniques have been studied for their potential therapeutic implications in the treatment of HCC. Nanoparticle-based imaging could be effective for more accurate HCC diagnosis. Since its inception, nanomedicine has significantly transformed the approach to both the treatment and diagnostics of liver cancer. Nanoparticles (NPs) are being studied as a potential treatment for liver cancer because of their ability to carry small substances, such as treatment with chemotherapy, microRNA, and therapeutic genes. The primary focus of this study is on the most current discoveries and practical uses of nanomedicine-based diagnostic and therapeutic techniques for liver cancer. In this section, we had gone over what we know about metabolic dysfunction in HCC and the treatment options that attempt to fix it by targeting metabolic pathways. Furthermore, we propose a multi-target metabolic strategy as a viable HCC treatment option. Based on the findings given here, the scientists believe that smart nanomaterials have great promise for improving cancer theranostics and opening up new avenues for tumor diagnosis and treatment.

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

BACKGROUND AND AIMS

Treatment of de novo malignancies and recurrent hepatocellular carcinoma with immune checkpoint inhibitors (ICI) in liver transplant recipients (LT) is an attractive strategy that is infrequently pursued because of the lack of strong evidence regarding their safety and efficacy. In this systematic review with pooled analysis, we aimed to assess safety and efficacy of ICI therapy following LT.

METHODS

We performed a systematic search of case reports and series published until January 2022. We included 31 publications reporting a total of 52 patients treated with ICIs after LT and assessed in a pooled analysis the risk of graft rejection and the outcome of ICI therapy.

RESULTS

Acute graft rejection occurred in 15 patients (28.8%) and 7 patients (13.4% of the total cohort) died because of graft loss. Rejection was associated with shorter overall survival (OS) (17.2 months, confidence interval [CI] 12.1-22.2 vs. 3.5 months, CI 1.6-5.4, p < 0.001). Disease control rate was 44.2% (n = 23), and in these patients, OS was longer than in non-responders (26.4 months, CI 20.8-32.0 vs. 3.4 months, CI 2.1-4.7, p < 0.001).

CONCLUSIONS

Observational, off-label experience suggests that treatment with ICI for advanced malignancies in LT recipients might not be discarded a priori. This notwithstanding, ICI treatment in these patients is associated with a substantial risk of graft rejection and mortality. Prospective studies are needed to provide adequate safety and efficacy figures of ICI treatment in this fragile population.

Immune microenvironment and therapeutic progress of recurrent hepatocellular carcinoma after liver transplantation

HCC is a highly lethal tumor, and orthotopic liver transplantation, as one of the radical treatment methods for HCC, has opened-up a new therapeutic approach for the treatment of primary liver cancer. However, tumor recurrence after liver transplantation is the main reason that affects the long-term survival of recipients. At present, the application of ICIs has brought dawn to patients with refractory HCC. However, because of the special immune tolerance state created by long-term oral immunosuppressants in patients with HCC after liver transplantation, the current focus is how to regulate the immune balance of such patients and simultaneously maximize the anti-tumor effect. This article reviews the relationship between liver cancer and immunity, immune tolerance of liver transplantation, immune microenvironment after liver transplantation for HCC, and the application of immunotherapy in the recurrence of liver transplantation for HCC.

Low-dose PD-1 inhibitor combined with lenvatinib for preemptive treatment of recurrence after liver transplantation for hepatocellular carcinoma: Case report and literature review

Orthotopic liver transplantation (OLT), as one of the curative methods for the treatment of hepatocellular carcinoma (HCC), has brought hope to patients with HCC. However, treatment options for HCC recurrence and metastasis after liver transplantation are limited. Immune checkpoint inhibitor (ICI), such as programmed cell death protein 1 (PD-1) inhibitor, have been successfully used in advanced or metastatic HCC, but the data on the safety of PD-1 inhibitor after liver transplantation is limited. In this article, we report a 47-year-old patient with acute-on-chronic liver failure and multiple HCC who was successfully treated with liver transplantation. On the 45th day after OLT, the patient’s alpha fetoprotein (AFP) and lens culinaris agglutinin-reactive fraction of AFP (AFP-L3) were increased, and imaging examination showed no residual tumor. The patient had high risk factors for tumor recurrence before operation, so the possibility of tumor recurrence was considered. When the tumor markers showed an upward trend, we immediately treated the patient with lenvatinib 8 mg, after half a month, the AFP and AFP-L3 continued to increase compared with before. Then we used low-dose nivolumab 40mg, the patient’s AFP and AFP-L3 gradually decreased. One month later, a second low-dose nivolumab 40mg was given, and the patient’s tumor markers gradually decreased to normal. No acute rejection and other complications occurred during the treatment. So far, we have followed up this patient for 2 years, and no tumor recurrence was observed. To our knowledge, this is the first reported case using a low dose of nivolumab in combination with lenvatinib to prevent recurrence of HCC after liver transplantation.

Advances in novel systemic therapies for advanced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents the most frequent type of primary liver tumor. Most HCC patients present with advanced disease at diagnosis and the recurrence rate after surgery remains high. Treatment options for advanced HCC are limited, with sorafenib representing the only systemic agent approved for treatment of advanced HCC in more than a decade. However, in recent years new molecular targeted therapies and immune checkpoint inhibitors (ICIs) have revolutionized the treatment of advanced HCC. In particular, combinations of ICIs with antiangiogenic drugs, or with other ICIs, represent one of the most promising strategies. Herein we provide a comprehensive overview of the main therapeutic advances in the systemic treatment of HCC, focusing on the most relevant ongoing clinical trials.

Utilization of Immunotherapy for the Treatment of Hepatocellular Carcinoma in the Peri-Transplant Setting: Transplant Oncology View

Simple Summary

Hepatocellular carcinoma is the second most common cause of cancer-related deaths and accounts for over eighty percent of primary liver cancers worldwide. Regarding the Milan Criteria, only a small portion of HCC patients are eligible for liver transplantation due to advanced-stage disease and large tumor size preventing/delaying organ allocation. Recently, the use of anti-programmed cell death protein 1 and programmed cell death ligand 1 (PD-1 and PD-L1) checkpoint inhibitors in the treatment of cancers have evolved rapidly and these therapies have been approved for the treatment of HCC, however, the main concerns about organ rejection in liver transplant patients who will be treated with ICPIs are still the same in both pre-and post-transplant setting. To alleviate those concerns, more global collaborations to explore the safety and efficacy of ICPIs in both the pre-and post-organ transplantation settings are required. The decision to administer ICPI treatment in liver transplant patients should be made on a case-by-case basis according to the goal of care and the availability and efficacy of other treatment options.

Abstract

Hepatocellular carcinoma (HCC) represents the second most common cause of cancer-related deaths and accounts for over eighty percent of primary liver cancers worldwide. Surgical resection and radiofrequency ablation in small tumors are included in the treatment options for HCC patients with good liver function profiles. According to the Milan Criteria, only a small portion of HCC patients are eligible for liver transplantation due to advanced-stage disease and large tumor size preventing/delaying organ allocation. Recently, the use of anti-programmed cell death protein 1 and programmed cell death ligand 1 (PD-1 and PD-L1) checkpoint inhibitors in the treatment of cancers have evolved rapidly and these therapies have been approved for the treatment of HCC. Immune checkpoint inhibitors have resulted in good clinical outcomes in pre-and post-transplant HCC patients, although, some reports showed that certain recipients may face rejection and graft loss. In this review, we aim to illustrate and summarize the utilization of immune checkpoint inhibitor therapies in pre-and post-liver transplants for HCC patients and discuss the assessment of immune checkpoint inhibitor regulators that might determine liver transplant outcomes.

Immunotherapy in liver transplantation for hepatocellular carcinoma: Pros and cons

Liver transplantation (LT) has emerged as a curative strategy for hepatocellular carcinoma (HCC), but contributes to a higher predisposition to HCC recurrence in the immunosuppression context, especially for tumors beyond the Milan criteria. Although immunotherapy has dramatically improved survival for immunocompetent patients and has become the standard of care for a variety of tumors, including HCC, it is mainly used outside the scope of organ transplantation owing to potentially fatal allograft rejection. Nevertheless, accumulative evidence has expanded the therapeutic paradigms of immunotherapy for HCC, from downstaging or bridging management in the pretransplant setting to the salvage or adjuvant strategy in the posttransplant setting. Generally, immunotherapy mainly includes immune checkpoint inhibitors (ICIs), adoptive cell transfer (ACT) and vaccine therapy. ICIs, followed by ACT, have been most investigated in LT, with some promising results. Because of the complex tumor microenvironment and immunoreactivity when immunosuppressants are combined with immunotherapy, it is difficult to reach formulations for immunosuppressant adjustment and the optimal selection of immunotherapy as well as patients. In addition, the absence of effective biomarkers for identifying rejection and tumor response is still an unresolved barrier to successful clinical immunotherapy applications for LT. In this review, we comprehensively summarize the available evidence of immunotherapy used in LT that is specific to HCC. Moreover, we discuss clinically concerning issues regarding the concurrent goals of graft protection and antitumor response.

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.

Cross-Match as an Immuno-Oncological Risk Factor for Hepatocellular Carcinoma Recurrence and Inferior Survival After Living Donor Liver Transplantation: A Call for Further Investigation

Background:

The success of immunotherapy for patients with hepatocellular carcinoma (HCC) suggests that immune dysregulation occurs in HCC patients. This warrants an immuno-oncological risk assessment in the platform of liver transplantation.

Methods:

This retrospective single-center study analyzed risk factors for—particularly cross-matching performed through conventional complement-dependent cytotoxicity cross-match tests—and the outcomes of HCC recurrence following living donor liver transplant.

Results:

A total of 71 patients were included. The median follow-up period was 29.1 months; 17 (23.9%) patients had posttransplant HCC recurrence, and their 1-, 3-, and 5-year-survival rates were 70.6%, 25.7%, and 17.1%, respectively, which were inferior to those of patients without HCC recurrence (87.0%, 80.7%, and 77.2%, respectively; P < .001). In addition to microvascular invasion, positive cross-match results for B cells at 37°C (B- 37°C) or T cells at 4°C (T- 4°C) were associated with inferior overall survival in multivariable analysis after adjustment for tumor status beyond Milan criteria and elevated alpha-fetoprotein levels. Rejection alone cannot be the mechanism underlying the effects of positive cross-match results on patient outcomes. Adjusted survival curves suggested that positive cross-match B- 37°C or T- 4°C was associated with inferior recurrence-free and patient survival, but the robustness of the finding was limited by insufficient power.

Conclusions:

Additional large-scale studies are required to validate positive cross-match as an immuno-oncological factor associated with HCC recurrence and inferior patient survival.

Immuno-Oncotherapeutic Approaches in Advanced Hepatocellular Carcinoma

Advanced hepatocellular carcinoma has limited treatment options, but there has been extensive growth recently with cabozantinib, regorafenib, lenvatinib, nivolumab, atezolizumab, and bevacizumab, which are some of the treatments that have received FDA approval just over the last three years. Because HCC tumor microenvironment is potentially immunogenic and typically characterized by inflammation, immunotherapy has been proposed as a potential novel therapeutic approach, which has prompted studies in advanced HCC patients investigating various immune-therapeutic strategies such as CAR-T cell therapy, checkpoint inhibitors, and onco-vaccines. The anti-PD-1 checkpoint inhibitors nivolumab and pembrolizumab have been FDA approved as a second line treatment in patients who progressed or are intolerant to Sorafenib. To build up on the success of PD-1 monotherapy, combinatorial regimens with PD-1/PD-L1 inhibitors plus VEGF targeted agents have shown positive results in various malignancies including HCC. The combination of atezolizumab plus bevacizumab is the new addition to the HCC treatment armamentarium following a pivotal study that demonstrated an improvement in OS over frontline sorafenib. Other novel immune-based approaches and oncolytic viruses are in the early phases of clinical evaluation. These innovative approaches enhance the intensity of cancer-directed immune responses and will potentially impact the outlook of this aggressive disease.

Neoadjuvant therapy and immunotherapy strategies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers with high mortality rate worldwide. Due to aggressive and invasive characteristics of HCC, poor prognosis is often displayed at advanced stages while therapeutic options are limited. Liver resection is still an essential curative-intent treatment in HCC management, while locoregional and systematic therapies made promising advances that may improve the proportion and outcomes of patients who are surgical candidates. In this review, we discussed status of currently available neoadjuvant treatments aimed at improving resectability and reducing recurrence rates. More than ever, in order to implement this therapeutic concepts and exploit the full potential of neoadjuvant treatment strategies, it is of utmost importance to use more high-level evidence to guide treatment decision making. Unfortunately, the use of preoperative treatments is not sponsored by tough evidence and consensus guidelines are absent.

Role and mechanism of programmed death-ligand 1 in hypoxia-induced liver cancer immune escape

Immune escape plays a vital role in the development of liver cancer. The interaction between programmed death-ligand 1 (PD-L1) and programmed cell death-1 is a key mediator of cancer immune escape, which leads to the suppression of anticancer immunity and promotion of tumor progression. Hypoxia is a common phenomenon in the tumor microenvironment. Under hypoxic conditions, suppressive immune cells, such as regulatory T cells, myeloid-derived suppressor cells and M2 macrophages, are frequently recruited to tumor tissues to form the immunosuppressive microenvironment in liver cancer. These cells secrete cancer-promoting inflammatory cytokines, which activate the STAT3 and NF-κB signaling pathways. Recent studies have shown that STAT3 is associated with NF-κB and that these transcription factors are often co-activated to regulate tumor proliferation, survival, angiogenesis and invasion. The activation of STAT3 and NF-κB signaling pathways can directly and indirectly induce PD-L1 expression. Therefore, further understanding of the association between hypoxia and PD-L1 may help in the future treatment of liver cancer. The present review summarizes the recent progresses on PD-L1-mediated regulation and facilitation of liver cancer cell immune escape in response to hypoxia.

Successful Treatment of Disseminated Hepatocellular Carcinoma After Liver Transplantation With Nivolumab

The use of immunotherapy in transplant recipients is considered a contraindication because of very high risks for graft loss. The graft loss is to be expected because cytotoxic T-lymphocyte-associated protein-4 and programmed death 1 pathways are implicated in graft tolerance. In this case report, we describe a woman with recurrent, disseminated hepatocellular carcinoma who was successfully treated with nivolumab, an immune checkpoint inhibitor.

Challenges in liver cancer and possible treatment approaches

Globally, liver cancer is the most frequent fatal malignancy; in the United States, it ranks fifth. Patients are often diagnosed with liver cancer in advanced stages, contributing to its poor prognosis. Of all liver cancer cases, >90% are hepatocellular carcinomas (HCCs) for which chemotherapy and immunotherapy are the best options for therapy. For liver cancer patients, new treatment options are necessary. Use of natural compounds and/or nanotechnology may provide patients with better outcomes with lower systemic toxicity and fewer side effects. Improved treatments can lead to better prognoses. Finally, in this review, we present some of the problems and current treatment options contributing to the poor outcomes for patients with liver cancer.

Medical oncology management of advanced hepatocellular carcinoma 2019: a reality check

In terms of global cancer-related deaths, hepatocellular carcinoma (HCC) has the fourth highest mortality rate. Up until 2017, treatment of advanced HCC was largely limited to sorafenib, an oral tyrosine kinase inhibitor, with little to no success in the development of alternative treatment options. However, in the past two years, there has been an unprecedented increase in both the number and type of treatment options available for HCC. As of 2019, the US FDA has approved four oral tyrosine kinase inhibitors, two immune checkpoint inhibitors, and one anti-angiogenesis antibody for the treatment of HCC. Even with this new variety, systemic treatment of advanced HCC remains largely unsatisfactory, and the median survival rate stands at approximately one year. The expected breakthrough of using immune checkpoint inhibitors in advanced HCC did not materialize in 2019. The use of immune checkpoint inhibitors in conjunction with oral tyrosine kinase inhibitors or anti-angiogenesis medications is the current clinical research trend, the results of which are eagerly anticipated. Despite limited progress in survival, HCC research is currently experiencing a period of growth and innovation, and there is hope for significant advances in the treatment of advanced HCC as the field continues to develop.

125I suppressed the Warburg effect viaregulating miR-338/PFKL axis in hepatocellular carcinoma

OBJECTIVES

Iodine-125 (¹²⁵I) irradiation has been widely applied in the treatment of advanced multiple malignant tumors. However, the underlying mechanism of ¹²⁵I exerted an anti-tumor effect on hepatocellular carcinoma (HCC) was largely unknown.

METHODS

In both HCCLM3 and SMMC-7721 cells, the effect of ¹²⁵I irradiation on the glycolysis was detected. The mRNA in HCC tissues and cell lines were detected by RT-qPCR. Cell proliferation, invasion and migration, and apoptosis were examined by CCK-8, Transwell, wound healing assay and flow cytometry assay, respectively. The interaction between miR-338 and PFKL (6-phosphofructokinase) were verified by dual-luciferase reporter gene assay. Western blotting was used to detect the expression of glycolysis-related proteins. We also evaluated the effect of ¹²⁵I seed implantation on the tumor growth and Warburg effect in vivo.

RESULTS

¹²⁵I irradiation significantly decreased the Warburg effect, cell proliferation, invasion and migration, and induced apoptosis of HCCLM3 and SMMC-7721 cells. miR-338 was upregulated in HCC cells treated with ¹²⁵I irradiation, which was a negative correlation with tumor size, tumor metastasis, and tumor development. Moreover, miR-338 directly interacted with PFKL and suppressed its expression. Mechanistically, ¹²⁵I irradiation significantly decreased the Warburg effect and exhibited anti-tumorigenesis function through upregulating the inhibitory effect of miR-338 on PFKL expression.

CONCLUSION

¹²⁵I irradiation upregulated the suppression of miR-338 on PFKL to downregulate the Warburg effect and anti-tumorigenesis in HCC and provided a new potential strategy for HCC clinical treatment.