Recurrence of Hepatocellular Carcinoma After Liver Transplantation is Associated with Episodes of Acute Rejections

Immunosuppression in liver transplant oncology: position paper of the Italian Board of Experts in Liver Transplantation (I-BELT)

Liver transplant oncology (TO) represents an area of increasing clinical and scientific interest including a heterogeneous group of clinical-pathological settings. Immunosuppressive management after LT is a key factor relevantly impacting result. However, disease-related guidance is still lacking, and many open questions remain in the field. Based on such a substantial lack of solid evidences, the Italian Board of Experts in Liver Transplantation (I-BELT) (a working group including representatives of all national transplant centers), unprecedently promoted a methodologically sound consensus conference on the topic, based on the GRADE approach. The group final recommendations are herein presented and commented. The 18 PICOs and Statements and their levels of evidence and grades of recommendation are reported and grouped into seven areas: (1) risk stratification by histopathological and bio-molecular parameters and role of mTORi post-LT; (2) steroids and HCC recurrence; (3) management of immunosuppression when HCC recurs after LT; (4) mTORi monotherapy; (5) machine perfusion and HCC recurrence after LT; (6) physiopathology of tumor-infiltrating lymphocytes and immunosuppression, the role of inflammation; (7) immunotherapy in liver transplanted patients. The interest in mammalian targets of rapamycin inhibitors (mTORi), for steroid avoidance and the need for a reduction to CNI exposure emerged from the consensus process. A selected list of unmet needs prompting further investigations have also been developed. The so far heterogeneous and granular approach to immunosuppression in oncologic patients deserves greater efforts for a more standardized therapeutic response to the different clinical scenarios. This consensus process makes a first unprecedented step in this direction, to be developed on a larger scale.

Detrimental impact of immunosuppressive burden on clinical course in patients with Cytomegalovirus infection after liver transplantation

INTRODUCTION

Cytomegalovirus (CMV)-infection and reactivation remain a relevant complication after liver transplantation (LT). The recipient and donor serum CMV-IgG-status has been established for risk stratification when choosing various pharmaceutical regimens for CMV-prophylaxis in the last two decades. However, factors influencing course of CMV-infection in LT remain largely unknown. In this study, the impact of immunosuppressive regimen was examined in a large cohort of patients.

METHODS

All patients that underwent primary LT between 2006 and 2018 at the Charité-Universitaetsmedizin, Berlin, were included. Clinical course as well as histological and laboratory findings of patients were analyzed our prospectively maintained database. Univariate and multivariate regression analysis for impact of variables on CMV-occurrence was conducted, and survival was examined using Kaplan-Meier analysis.

RESULTS

Overall, 867 patients were included in the final analysis. CMV-infection was diagnosed in 325 (37.5%) patients after transplantation. Significantly improved overall survival was observed in these patients (Log rank = 0.03). As shown by correlation and regression tree classification and regression tree analysis, the recipient/donor CMV-IgG-status with either positivity had the largest influence on CMV-occurrence. Analysis of immunosuppressive burden did not reveal statistical impact on CMV-infection, but statistically significant inverse correlation of cumulative tacrolimus trough levels and survival was found (Log rank < .001). Multivariate analysis confirmed these findings (p = .02).

DISCUSSION

CMV-infection remains of clinical importance after LT. Undergone CMV-infection of either recipient or donor requires prophylactic treatment. Additionally, we found a highly significant, dosage-dependent impact of immunosuppression (IS) on long-term outcomes for these patients, underlying the importance of minimization of IS in liver transplant recipients.

Inhibition of DNMT3B expression in activated hepatic stellate cells overcomes chemoresistance in the tumor microenvironment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a complex disease associated with a plethora of environmental and genetic/hereditary causative risk factors, more so than other oncological indications. Additionally, patients with HCC exhibit fibrosis, cirrhosis, and liver-related disease. This complicated etiology can affect the disease course and likely contributes to its poor prognosis. In this study, we aimed to improve HCC therapy by evaluating combination treatment using anti-cancer and anti-fibrosis drugs via identification of novel anti-fibrosis drugs. We performed high-throughput screening of 10,000 compounds to identify hepatic fibrosis inhibitors through morphometry analysis of multicellular hepatic spheroid (MCHS) models and identified CHIR-99021 as a candidate anti-fibrotic drug. Treatment with CHIR-99021 induced loss of cell-cell interactions and suppression of extracellular matrix-related protein expression via reprogramming of hepatic stellate cell (HSC) activation in MCHSs. In particular, CHIR-99021 regulated DNMT3B expression only in activated HSCs. Moreover, CHIR-99021 markedly improved the efficacy of sorafenib in HCC- multicellular tumor spheroids in vitro and through induction of apoptosis by decreasing DNMT3B expression in vivo. In summary, these findings suggest that targeting HSC reprogramming by attenuation of DNMT3B expression in the tumor environment might represent a promising therapeutic strategy for liver fibrosis and HCC.

Preoperative Immunotherapy in Hepatocellular Carcinoma: Current State of the Art

Hepatocellular carcinoma (HCC) is a malignancy that requires multidisciplinary evaluation to develop individualized and tailored treatment concepts. While liver resection and transplantation represent the mainstay of curative treatment in patients with early-stage HCC, disease recurrence remains an important burden. Immune checkpoint inhibitors (ICI) have become standard of care in the palliative setting, achieving promising response rates with overall good tolerability. Accordingly, ICIs are being evaluated in (neo)adjuvant concepts in order to improve survival. Nevertheless, neoadjuvant therapies are not recommended by current guidelines as they have not been proven to improve the outcome in large Phase III trials yet. Especially in the context of liver transplantation (LT), perioperative ICI usage is in need of a particularly critical risk-benefit assessment, as the immunotherapy may significantly increase the risk of rejection. In this review, we summarize available data on ICI-based perioperative treatment strategies in HCC. We discuss current drawbacks and challenges of this treatment concept and specifically highlight the risk of allograft rejection when ICI are given in patients (subsequently) considered for liver transplantation.

Chromenopyrimidinone exhibit antitumor effects through inhibition of CAP1 (Adenylyl cyclase-associated protein 1) expression in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most malignant human cancers, with a high mortality rate worldwide. Within an HCC tumor, cancer stem cells (CSCs) are responsible for tumor maintenance and progression and may contribute to resistance to standard HCC treatments. Previously, we characterized CD133⁺ cells as CSCs in primary HCC and identified chromenopyrimidinone (CPO) as a novel therapeutic for the effective treatment of CD133⁺ HCC. However, the biological function and molecular mechanism of CD133 remain unclear. Epigenetic alterations of CSCs have impacts on tumor initiation, progression, and therapeutic response. Here, we found that pharmacological and genetic depletion of CD133 in HCC attenuated the activity of DNA methyltransferases via control of DNMT3B stabilization. Genes were ranked by degree of promoter hypo/hyper methylation and significantly differential expression to create an "epigenetically activated by CPO" ranked genes list. Through this epigenetic analysis, we found that CPO treatment altered DNA methylation-mediated oncogenic signaling in HCCs. Specifically, CPO treatment inhibited Adenylyl cyclase-associated protein 1 (CAP1) expression, thereby reducing FAK/ERK activity and EMT-related proteins in HCC. Moreover, CPO improved the efficacy of sorafenib by inhibiting CAP1 expression and FAK/ERK activation in sorafenib-resistant HCC. These novel mechanistic insights may ultimately open up avenues for strategies targeting DNA methylation in liver cancer stem cells and provides novel therapeutic function of CPO for the effective treatment of sorafenib-resistant HCC.

Hepatocellular Carcinoma Intrinsic Cell Death Regulates Immune Response and Prognosis

Ablative and locoregional treatment options, such as radiofrequency, ethanol injection, microwave, and cryoablation, as well as irreversible electroporation, are effective therapies for early-stage hepatocellular carcinoma (HCC). Hepatocyte death caused by ablative procedures is known to increase the release of tumor-associated antigen, thus enhancing tumor immunogenicity. In addition, the heat ablative resection induces pyroptotic cell death accompanied by the release of several inflammatory factors and immune-related proteins, including damage-associated molecular patterns (DAMPs), heat shock proteins (HSPs), ficolin 3, ATP, and DNA/RNA, which potentiate the antitumoral immune response. Surgical approaches that enhance tumor necrosis and reduce hypoxia in the residual liver parenchyma have been shown to increase the disease-free survival rate by reducing the host’s immunosuppressive response. Scalpel devices and targeted surgical approach combined with immune-modulating drugs are an interesting and promising area to maximize therapeutic outcomes after HCC ablation.

Preoperative Prognostic Nutritional Index May Be a Strong Predictor of Hepatocellular Carcinoma Recurrence Following Liver Transplantation

Purpose

Malnutrition is a major risk factor of immune dysfunction and poor outcome in cancer patients. The prognostic nutritional index (PNI), which is established by serum albumin level and peripheral lymphocyte count, was shown to correlate with prognosis of hepatocellular carcinoma (HCC) patients following liver resection and non-surgical interventions. The aim of this study was to analyze the predictive value of preoperative PNI in liver transplantation (LT) patients with HCC.

Patients and Methods

A total of 123 HCC patients that underwent LT were included in the analysis. The prognostic impact of preoperatively assessed clinical factors including the PNI on post-LT outcome was analyzed by uni- and multivariate analysis.

Results

Post-transplant tumor recurrence rates were 5.1% in high-PNI (> 42) and 55.6% in low-PNI (≤ 42) patients (p < 0.001). Preoperative high-PNI could be identified as a significant and independent promoter of both recurrence-free survival (hazard ratio [HR] = 10.12, 95% CI: 3.40–30.10; p < 0.001) and overall survival (HR = 1.69, 95% CI: 1.02–2.79; p = 0.004) following LT. Apart from that low-PNI proved to be a significant and independent predictor of microvascular tumor invasion (OR = 7.71, 95% CI: 3.17–18.76; p < 0.001). In contrast, no tumor morphology features including the Milan criteria revealed an independent prognostic value.

Conclusion

Our data indicate that preoperative PNI correlates with biological tumor aggressiveness and outcome following LT in HCC patients and may therefore be useful for refining oncologic risk stratification.

The Role of Immunosuppression for Recurrent Cholangiocellular Carcinoma after Liver Transplantation

Liver transplantation (LT) for cholangiocarcinoma (CCA), or biliary tract cancer (BTC), remains controversial regarding high recurrence rates and poor prognosis. Oncological follow-up may benefit from tumor-inhibiting properties of mTOR inhibitors (mTORI), shown with improved survival for recurrent hepatocellular carcinoma (HCC) patients after LT. The aim of this study was to investigate the recurrence and survival in relation to tumor type and type of immunosuppression (IS). LT patients with CCA or mixed HCC/CCA (mHCC/CCA) (n = 67) were retrospectively analyzed. Endpoints were the time from LT to recurrence (n = 44) and survival after recurrence. Statistically significant impairment in survival for recurrent CCA (rCCA) was shown in patients not eligible for surgical resection (HR 2.46 (CI: 1.2−5.1; p = 0.02). Histological proven grading >1 and N1 status at initial transplantation were associated with impaired survival (HR 0.13 (CI: 0.03−0.58); p < 0.01 and HR 3.4 (CI: 1.0−11.65); p = 0.05). Reduced IS after tumor recurrence improved survival (HR 4.2/CI: 1.3−13.6; p = 0.02). MTORI initiation before recurrence or after had no significant impact on survival. Our data thereby indicate, similar to findings in recurrent HCC after LT, that patients with rCCA after LT benefit from a reduction in IS upon recurrence.

The RETREAT score provides valid predictions regarding hepatocellular carcinoma recurrence after liver transplantation

Prediction of hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT) with knowledge of explant data is important for guiding post-LT surveillance and treatment. The RETREAT score was recently introduced for this purpose, but has not been validated outside the USA. In a retrospective single-center study of 169 consecutive patients undergoing LT in Gothenburg, through 2000-2017 (mean age 57 years, 80% men), there were 34 HCC recurrences during a median 4.6-year follow-up. The 5-year cumulative incidence of HCC recurrence was 0% with RETREAT scores of 0-1 (18%), 11-22% with scores of 2-4 (58%), and 65% with scores of 5-8 (24%). The C-statistic, as a measure of discrimination for prediction of HCC recurrence was 0.762, 0.664, 0.616, and 0.717, for the RETREAT score, Milan criteria, UCSF criteria, and post-MORAL criteria. The RETREAT score had no significant impact on patient survival after HCC recurrence (HR 1.00, P = 0.97). In conclusion, the RETREAT score provided valid predictions of post-LT HCC recurrence in a European setting, with the ability to discriminate between high, intermediate, and low risk for HCC recurrence in a clinically important way. Prognosis after recurrence did not differ according to the RETREAT score in our study.

[The use of immuno-oncologic therapy in hepatocellular carcinoma in the context of liver transplantation. An interdisciplinary benefit/risk assessment]

BACKGROUND

Multiple systemic therapy options have been recently approved for the treatment of hepatocellular carcinoma (HCC). In particular, immuno-oncology combination therapies can now achieve impressive response rates and significantly prolonged survival with good tolerability. These immuno-oncology (IO)-based combinations are currently not only evaluated for the therapy of advanced HCC, but increasingly also in earlier stages in terms of peri-interventional therapy concepts and also for down-sizing to local therapies. In the context of liver transplantation (LTx), a particularly critical benefit/risk assessment must be made before the use of immunotherapeutics in the context of multimodal concepts, since the risk of a potentially lethal rejection can be significantly increased by immunotherapy.

METHODS

This review is based on a selective literature search performed between December 2020 and April 2021 in the PubMed and Cochrane Library databases. Guidelines, expert opinions, and recommendations from professional societies were given special consideration.

RESULTS

Nearly one in five LTx in Germany are performed due to HCCs. In this context, LTx is a curative therapy option not only for the underlying liver disease but also for the malignant tumor. Individual case reports indicate that IO therapy prior to LTx may increase the risk of rejection or liver failure after subsequent liver transplantation. Since 2015, immunotherapeutics have also been widely used for tumor therapy in patients after LTx. In small case series, rejection rates of 36%, associated with rejection-related mortality of 20% of treated patients, have been described. A similar incidence of rejection has also been described following the use of immunotherapeutics in patients after other organ transplantations.

CONCLUSION

In the context of organ transplantation, IO therapy carries the risk of graft rejection, which can lead to graft loss and also patient death. However, from today's point of view, IO-based therapy can be considered in the context of organ transplantation with a careful benefit/risk assessment.