Liver Transplantation for Hepatocellular Carcinoma beyond Milan Criteria: Multidisciplinary Approach to Improve Outcome

New Developments and Challenges in Liver Transplantation

Liver disease is increasing in incidence and is the third most common cause of premature death in the United Kingdom and fourth in the United States. Liver disease accounts for 2 million deaths globally each year. Three-quarters of patients with liver disease are diagnosed at a late stage, with liver transplantation as the only definitive treatment. Thomas E. Starzl performed the first human liver transplant 60 years ago. It has since become an established treatment for end-stage liver disease, both acute and chronic, including metabolic diseases and primary and, at present piloting, secondary liver cancer. Advances in surgical and anaesthetic techniques, refined indications and contra-indications to transplantation, improved donor selection, immunosuppression and prognostic scoring have allowed the outcomes of liver transplantation to improve year on year. However, there are many limitations to liver transplantation. This review describes the milestones that have occurred in the development of liver transplantation, the current limitations and the ongoing research aimed at overcoming these challenges.

Diagnostic accuracy and prognostic significance of osteopontin in liver cirrhosis and hepatocellular carcinoma: a Meta-analysis

OBJECTIVE

At present, there is no definite suggestion about effective tumour biomarkers for the diagnostic accuracy and prognostic significance of hepatocellular carcinoma (HCC) and liver cirrhosis (LC). The aim of our research was to determine the value of the tumour biomarker osteopontin (OPN), which is encoded by the Spp1 gene, in the diagnosis, prognosis and development of HCC and LC through meta-analysis.

METHODS

A systematic literature search was performed in the PubMed, Embase, Cochrane Library and China National Knowledge Infrastructure electronic databases up to March 2021. Studies evaluating the diagnostic and/or prognostic value of OPN in HCC and/or LC were included.

RESULTS

From the systematic search, 35 studies including 9150 participants were eligible, 25 of which provided data on the diagnostic value of OPN overexpression, while 15 studies provided data on the prognostic value. OPN had high diagnostic accuracy in both HCC and LC patients compared with healthy controls, and the diagnostic efficiency was increased by the biomarker combination OPN + AFP.

CONCLUSIONS

OPN may be adopted as a promising predictive tumour biomarker for the diagnosis and prognosis of HCC and LC and may be a potential therapeutic target.

Living donor liver transplantation for hepatic malignancies in children

BACKGROUND

Living donor liver transplantation is a treatment option for unresectable hepatic tumors in children.

METHODS

We enrolled 45 living donor transplantations performed between 1993 and 2018 for liver malignacies, which included hepatoblastoma (n = 33), hepatocellular carcinoma (n = 10), hepatic angiosarcoma (n = 1), and rhabdomyosarcoma (n = 1).

RESULTS

No mortality or major morbidities were encountered in any donor, and the complication rate was 9%. In the hepatoblastoma group, 5-year overall and event-free survival rate in recipients was 87.4% and 75.8%, respectively, and mortality was significantly higher in patients after rescue transplantation (p = .001). Inferior vena cava replacement in these recipients appeared to be associated with reduced mortality (p = .034), but this was not confirmed when rescue patients were excluded (p = .629). In hepatocellular carcinoma group, both 5-year overall and event-free survival rates were 75.4% each, and invasion of hepatic veins was significantly associated with increased risk of recurrence and death (p = .028). The patient with rhabdomyosarcoma died from EBV-induced lymphoma 2 months after transplantation. The patient with angiosarcoma was in complete remission at the last follow-up. Overall, 5-year graft survival rate was 81.3%, and one patient underwent re-transplantation due to chronic rejection.

CONCLUSIONS

Pediatric oncological liver transplantation has become a key player in the management of malignancies with cancer cure in 84% of patients in this series. Living donor liver transplantation for pediatric recipients with unresectable tumors might be a beneficial surgical option, which is technically safe for donors and recipients, thus, allowing timely planning according to chemotherapy protocols.

Exploration of the effects of the CYCLOPS gene RBM17 in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most lethal and malignant tumours worldwide. New therapeutic targets for HCC are urgently needed. CYCLOPS (copy number alterations yielding cancer liabilities owing to partial loss) genes have been noted to be associated with cancer-targeted therapies. Therefore, we intended to explore the effects of the CYCLOPS gene RBM17 on HCC oncogenesis to determine if it could be further used for targeted therapy.

METHODS

We collected data on 12 types of cancer from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) queries for comparison with adjacent non-tumour tissues. RBM17 expression levels, clinicopathological factors and survival times were analysed. RNAseq data were downloaded from the Encyclopaedia of DNA Elements database for molecular mechanism exploration. Two representative HCC cell models were built to observe the proliferation capacity of HCC cells when RBM17 expression was inhibited by shRBM17. Cell cycle progression and apoptosis were also examined to investigate the pathogenesis of RBM17.

RESULTS

Based on 6,136 clinical samples, RBM17 was markedly overexpressed in most cancers, especially HCC. Moreover, data from 442 patients revealed that high RBM17 expression levels were related to a worse prognosis. Overexpression of RBM17 was related to the iCluster1 molecular subgroup, TNM stage, and histologic grade. Pathway analysis of RNAseq data suggested that RBM17 was involved in mitosis. Further investigation revealed that the proliferation rates of HepG2 (P = 0.003) and SMMC-7721 (P = 0.030) cells were significantly reduced when RBM17 was knocked down. In addition, RBM17 knockdown also arrested the progression of the cell cycle, causing cells to halt at the G2/M phase. Increased apoptosis rates were also found in vitro.

CONCLUSION

These results suggest that RBM17 is a potential therapeutic target for HCC treatment.

Dietary Choline Supplementation Attenuates High-Fat-Diet-Induced Hepatocellular Carcinoma in Mice

BACKGROUND

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related death in the world. Choline deficiency has been well studied in the context of liver disease; however, less is known about the effects of choline supplementation in HCC.

OBJECTIVE

The objective of this study was to test whether choline supplementation could influence the progression of HCC in a high-fat-diet (HFD)-driven mouse model.

METHODS

Four-day-old male C57BL/6J mice were treated with the chemical carcinogen, 7,12-dimethylbenz[a]anthracene, and were randomly assigned at weaning to a cohort fed an HFD (60% kcal fat) or an HFD with supplemental choline (60% kcal fat, 1.2% choline; HFD+C) for 30 wk. Blood was isolated at 15 and 30 wk to measure immune cells by flow cytometry, and glucose-tolerance tests were performed 2 wk prior to killing. Overall tumor burden was quantified, hepatic lipids were measured enzymatically, and phosphatidylcholine species were measured by targeted MS methods. Gene expression and mitochondrial DNA were quantified by quantitative PCR.

RESULTS

HFD+C mice exhibited a 50-90% increase in both circulating choline and betaine concentrations in the fed state (P ≤ 0.05). Choline supplementation resulted in a 55% decrease in total tumor numbers, a 67% decrease in tumor surface area, and a 50% decrease in hepatic steatosis after 30 wk of diet (P ≤ 0.05). Choline supplementation increased the abundance of mitochondria and the relative expression of β-oxidation genes by 21% and ∼75-100%, respectively, in the liver. HFD+C attenuated circulating myeloid-derived suppressor cells at 15 wk of feeding (P ≤ 0.05).

CONCLUSIONS

Choline supplementation attenuated HFD-induced HCC and hepatic steatosis in male C57BL/6J mice. These results suggest a therapeutic benefit of choline supplementation in blunting HCC progression.

Modeling of implementation of the new Organ Procurement and Transplantation Network/United Network for Organ Sharing policy for patients with hepatocellular carcinoma

Aim: To simulate effects of the new Organ Procurement and Transplantation Network/United Network for Organ Sharing policy on the patients' characteristics and post orthotopic liver transplantation (OLT) outcome. Materials & methods: The United Network for Organ Sharing database was used to identify patients with hepatocellular carcinoma who were listed for OLT 2002-2014. All patients (actual group) versus simulated group with new 6-month delay in assigning Model for End-Stage Liver Disease score exception and Model for End-Stage Liver Disease exception cap of 34 were compared. Results & conclusion: With the new policy, 7,745 (30.4%) of the transplanted patients would have received a delayed transplantation or not be transplanted. The simulated group also showed significantly higher mean overall survival after OLT (p < 0.002) and received more locoreginal treatments (p < 0.001).

Achieving Complete Remission of Hepatocellular Carcinoma: A Significant Predictor for Recurrence-Free Survival after Liver Transplantation

BACKGROUND

Liver transplantation (LT) is a curative treatment for hepatocellular carcinoma (HCC) and the underlying primary liver disease; however, tumor recurrence is still a major issue. Therefore, the aim of this study was to assess predictors and risk factors for HCC recurrence after LT in patients within and outside the Milan criteria with a special focus on the impact of different bridging strategies.

METHODS

All patients who underwent LT for HCC between 07/2002 and 09/2016 at the University Hospital of Muenster were consecutively included in this retrospective study. Database research was performed and a multivariable regression analysis was conducted to explore potential risk factors for HCC recurrence.

RESULTS

A total of 82 patients were eligible for the statistical analysis. Independent of bridging strategy, achieving complete remission (CR) was significantly associated with a lower risk for tumor recurrence (p = 0.029; OR = 0.426, 95% CI 0.198-0.918). A maximal diameter of lesion < 3 cm was also associated with lower recurrence rates (p = 0.040; OR = 0.140, 95% CI 0.022-0.914). Vascular invasion proved to be an independent risk factor for HCC recurrence (p = 0.004; OR = 11.357, 95% CI 2.142-60.199).

CONCLUSION

Achieving CR prior to LT results in a significant risk reduction of HCC recurrence after LT independent of the treatment modalities applied.

Accuracy of Milan, University of California San Francisco, and Up-To-7 Criteria in Predicting Tumor Recurrence Following Deceased-Donor Liver Transplant in Patients With Hepatocellular Carcinoma

OBJECTIVES

We aimed to investigate the accuracy of the Milan, University of California San Francisco, and Up-to-7 criteria in predicting tumor recurrence after liver transplant for hepatocellular carcinoma.

MATERIALS AND METHODS

For this study, 165 patients with deceased-donor liver transplant for hepatocellular carcinoma were evaluated. The Milan, University of California San Francisco, and Up-to-7 criteria were calculated based on explant pathology.

RESULTS

Tumor recurrence rate after liver transplant was 14.6%. Of 165 patients, 115 (70%) were within Milan, 131 (79%) were within University of California San Francisco, and 135 (82%) were within Up-to-7 criteria. The odds ratio of tumor recurrence in patients outside versus within criteria for Milan, University of California San Francisco, and Up-to-7 was 3.6 (95% confidence interval, 1.5-9.1; P = .005), 7.5 (95% confidence interval, 2.5-19.3; P < .001), and 7.5 (95% confidence interval, 2.9-19.6; P < .001) times higher, respectively. The sensitivity of being outside of Milan in predicting tumor recurrence was comparable to University of California San Francisco and Up-to-7 criteria (56.5%, 56.5%, and 52.2%, respectively). Specificity was highest in Up-to-7 (87.3%) versus 85.2% for University of California San Francisco and 73.9% for Milan criteria. The area under the curve for Milan, University of California San Francisco, and Up-to-7 criteria was 0.63, 0.65, and 0.63.

CONCLUSIONS

Application of standard criteria has significantly improved prediction of hepatocellular carcinoma recurrence. However, these criteria are inadequate, supporting the importance of other factors, including tumor biology. Research is ongoing in discovering novel biomarkers as predictors of tumor recurrence.

Selection of patients with hepatocellular carcinoma for liver transplantation: Past and future

The aim of liver transplantation (LT) for hepatocellular carcinoma (HCC) is to ensure a rate of disease-free survival similar to that of patients transplanted due to benign disease. Therefore, we are forced to adopt strict criteria when selecting candidates for LT and prioritizing patients on the waiting list (WL), to have clarified indications for bridging therapy for groups at risk for progression or recurrence, and to establish certain limits for downstaging therapies. Although the Milan criteria (MC) remain the standard and most employed criteria for indication of HCC patients for LT by far, in the coming years, criteria will be consolidated that take into account not only data regarding the size/volume and number of tumors but also their biology. This criteria will mainly include the alpha fetoprotein (AFP) values and, in view of their wide variability, any of the published logarithmic models for the selection of candidates for LT. Bridging therapy is necessary for HCC patients on the WL who meet the MC and have the possibility of experiencing a delay for LT greater than 6 mo or any of the known risk factors for recurrence. It is difficult to define single AFP values that would indicate bridging therapy (200, 300 or 400 ng/mL); therefore, it is preferable to rely on the criteria of a French AFP model score > 2. Other single indications for bridging therapy include a tumor diameter greater than 3 cm, more than one tumor, and having an AFP slope greater than 15 ng/mL per month or > 50 ng/mL for three months during strict monitoring while on the WL. When considering the inclusion of patients on the WL who do not meet the MC, it is mandatory to determine their eligibility for downstaging therapy prior to inclusion. The upper limit for this therapy could be one lesion up to 8 cm, 2-3 lesions with a total tumor diameter up to 8 cm, or a total tumor volume of 115 cm³. Lastly, liver allocation and the prioritization of patients with HCC on the WL should take into account the recently described HCC model for end-stage liver disease, which considers hepatic function, HCC size and the number and the log of AFP values. This formula has been calibrated with the survival data of non-HCC patients and produces a dynamic and more accurate assessment model.

Postoperative peak serum C-reactive protein is a predictor of outcome following liver transplantation for hepatocellular carcinoma

CONTEXT

C-reactive protein (CRP), a biomarker of inflammation, may correlate with prognosis in several malignancies.

OBJECTIVE

To investigate the prognostic impact of early postoperative peak serum levels of CRP on tumor-specific outcome in 106 liver transplant patients with hepatocellular carcinoma (HCC).

METHODS AND RESULTS

In multivariate Cox regression analysis, a posttransplant elevated peak CRP level (>versus ≤ 3.5 mg/dl) was identified as an independent predictor of poor recurrence-free survival (p = 0.01; HR = 4.04; CI = 1.399-11.640).

CONCLUSION

Early postoperative serum CRP may serve as a useful inflammation-based biomarker of outcome in liver transplant patients with HCC.

Treating ischaemia-reperfusion injury with prostaglandin E1 reduces the risk of early hepatocellular carcinoma recurrence following liver transplantation

BACKGROUND

Surgical stress by hepatic ischaemia-reperfusion (I/R) is supposed to promote intra- and extrahepatic tumour recurrence. Treatment with prostaglandin E1 (PGE1) has been shown to attenuate hepatic I/R injury in liver transplant patients, but the potential anti-cancer effects have not been analysed.

AIM

To evaluate the impact of PGE1 therapy on risk of hepatocellular carcinoma (HCC) recurrence in liver transplant patients.

METHODS

A retrospective review of 106 liver transplant patients with HCC was conducted. Fifty-nine patients underwent early post-liver transplantation (LT) treatment with the stable PGE1 analogue alprostadil. Administration of alprostadil was correlated with outcome in uni- and multivariate analysis. Subgroup analysis focused on patients with HCC beyond the Milan criteria (Milan Out) on radiographic imaging.

RESULTS

Three- and 5-year recurrence-free survival rates were 87.9% and 85.7% in the PGE1-group, but only 65.3% and 63.1% in the non-PGE1-population (P = 0.003). Multivariate Cox regression analysis identified absence of PGE1-treatment (HR = 11.42), along with presence of poor tumour grading (HR = 2.69) and microvascular tumour invasion (HR = 35.8) to be independently associated with early (within 12 months) HCC recurrence. In Milan Out-patients, only therapy with PGE1 (HR = 5.09) and well/moderate tumour differentiation (HR = 6.51) were independent promoters of recurrence-free survival.

CONCLUSIONS

Treating hepatic ischaemia-reperfusion injury with alprostadil reduces the risk of early HCC recurrence following LT. In particular patients with HCC exceeding the Milan criteria seem to benefit from PGE1-treatment. The molecular mechanisms of the anti-tumour effects need to be further assessed.

Extended Ischemia Times Promote Risk of HCC Recurrence in Liver Transplant Patients

BACKGROUND

There is increasing evidence that ischemia-reperfusion injury (IRI) promotes vasculogenesis and tumor outgrowth in the liver. Hepatic IRI is exaggerated by prolongation of ischemia times.

AIMS

The aim of this retrospective analysis was to assess the impact of ischemia times on risk of hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT). Subgroup analysis focused on patients with (18)F-fluoro-deoxy-glucose ((18)F-FDG)-avid HCC on pretransplant positron emission tomography (PET).

METHODS

A total of 103 liver transplant patients with HCC were included in this study. The impact of cold (CIT), warm (WIT), and total ischemia times (TIT) along with other prognostic variables on posttransplant outcome was analyzed in uni- and multivariate analysis.

RESULTS

Twenty-four patients (23.3 %) developed tumor relapse after LT. Mean durations of CIT (468.0 vs. 375.5 min; P = 0.001), WIT (58.4 vs. 45.7 min; P = 0.001), and TIT (525.8 vs. 422.0 min; P < 0.001) were significantly longer in patients with compared to those without HCC recurrence. In multivariate regression analysis, (18)F-FDG-avid HCC (odds ratio [OR] 73.4), WIT >50 min (OR 52.5), alpha-fetoprotein level >400 IU/ml (OR 11.1), and Milan Out status (OR 7.4) were identified as independent predictors of HCC recurrence. In the subgroup of patients with PET-positive HCC, WIT remained the only independent variable to predict HCC recurrence (OR 15.5).

CONCLUSION

Prolongation of ischemia times promotes the risk of HCC recurrence after LT, especially in patients with unfavorable tumor biology on PET imaging.

Paracrine signaling mediated at cell-cell contacts

Recent findings in several organ systems show that cytoneme-mediated signaling transports signaling proteins along cellular extensions and targets cell-to-cell exchanges to synaptic contacts. This mechanism of paracrine signaling may be a general one that is used by many (or all) cell types in many (or all) organs. We briefly review these findings in this perspective. We also describe the properties of several signaling systems that have previously been interpreted to support a passive diffusion mechanism of signaling protein dispersion, but can now be understood in the context of the cytoneme mechanism. Also watch the Video Abstract.