Liver transplantation for hepatocellular carcinoma: five steps to prevent recurrence

Effects of maintenance immunosuppression with sirolimus after liver transplant for hepatocellular carcinoma

For recipients of liver transplantations (LTs) for hepatocellular carcinoma (HCC), HCC recurrence after transplantation remains a major concern. Sirolimus (SRL), an immunosuppressant with anticarcinogenic properties, may reduce HCC recurrence and improve survival. In our study, the US Scientific Registry of Transplant Recipients was linked to pharmacy claims. For liver recipients transplanted for HCC, Cox regression was used to estimate associations of early SRL use with recurrence, cancer-specific mortality, and all-cause mortality, adjusting for recipient ethnicity, calendar year of transplant, total tumor volume, alpha-fetoprotein, transplant center size, use of interleukin 2 induction therapy, and allocated and calculated Model for End-Stage Liver Disease score. We performed stratified analyses among recipients who met Milan criteria, among those without renal failure, among those with deceased liver donors, by age at transplantation, and by tumor size. Among the 3936 included HCC LTs, 234 (6%) were SRL users. In total, there were 242 recurrences and 879 deaths, including 261 cancer-related deaths. All-cause mortality was similar in SRL users and nonusers (adjusted hazard ratio [aHR], 1.01; 95% CI, 0.73-1.39). HCC recurrence and cancer-specific mortality rates appeared lower in SRL users, but associations were not statistically significant (recurrence aHR, 0.86; 95% CI, 0.45-1.65; cancer-specific mortality aHR, 0.80; 95% CI, 0.43-1.50). Among recipients >55 years old, associations were suggestive of better outcomes for SRL users (all-cause mortality aHR, 0.62; 95% CI, 0.38-1.01; recurrence aHR, 0.52; 95% CI, 0.19-1.44; cancer-specific mortality aHR, 0.34; 95% CI, 0.11-1.09), whereas among recipients ≤55 years old, SRL users had worse outcomes (all-cause mortality aHR, 1.76; 95% CI, 1.12-2.75; recurrence aHR, 1.49; 95% CI, 0.62-3.61; cancer-specific mortality aHR, 1.54; 95% CI, 0.71-3.32). In conclusion, among HCC liver recipients overall, SRL did not appear beneficial in reducing all-cause mortality. However, there were suggestions of reductions in recurrence and cancer-specific mortality, and effects appeared to be modified by age at transplantation. Liver Transplantation 22 627-634 2016 AASLD.

Phosphorylated Heat Shock Protein 20 (HSPB6) Regulates Transforming Growth Factor-α-Induced Migration and Invasion of Hepatocellular Carcinoma Cells

Human hepatocellular carcinoma (HCC) is one of the major malignancies in the world. Small heat shock proteins (HSPs) are reported to play an important role in the regulation of a variety of cancer cell functions, and the functions of small HSPs are regulated by post-translational modifications such as phosphorylation. We previously reported that protein levels of a small HSP, HSP20 (HSPB6), decrease in vascular invasion positive HCC compared with those in the negative vascular invasion. Therefore, in the present study, we investigated whether HSP20 is implicated in HCC cell migration and the invasion using human HCC-derived HuH7 cells. The transforming growth factor (TGF)-α-induced migration and invasion were suppressed in the wild-type-HSP20 overexpressed cells in which phosphorylated HSP20 was detected. Phospho-mimic-HSP20 overexpression reduced the migration and invasion compared with unphosphorylated HSP20 overexpression. Dibutyryl cAMP, which enhanced the phosphorylation of wild-type-HSP20, significantly reduced the TGF-α-induced cell migration of wild-type HSP20 overexpressed cells. The TGF-α-induced cell migration was inhibited by SP600125, a c-Jun N-terminal kinases (JNK) inhibitor. In phospho-mimic-HSP20 overexpressed HuH7 cells, TGF-α-stimulated JNK phosphorylation was suppressed compared with the unphosphorylated HSP20 overexpressed cells. Moreover, the level of phospho-HSP20 protein in human HCC tissues was significantly correlated with tumor invasion. Taken together, our findings strongly suggest that phosphorylated HSP20 inhibits TGF-α-induced HCC cell migration and invasion via suppression of the JNK signaling pathway.

Identifying patients at higher risk of hepatocellular carcinoma recurrence after liver transplantation in a multicenter cohort study from Argentina

BACKGROUND AND AIM

The Up-to-7 criteria on the basis of the explanted liver features categorize patients at higher risk of hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT). The aim of this study was to propose a novel pretransplant scoring system to predict recurrence including pre-LT data.

PATIENTS AND METHODS

From 763 consecutive adult patients who underwent transplantation in four LT centers from Argentina, 124 patients with HCC were included. A scoring system was developed in 87 patients from pre-LT risk factors for recurrence as determined by hazard ratios (HRs) from a multivariate Cox regression analysis.

RESULTS

Overall survival and recurrence rates at 5 years were 63.3 and 13.7%, respectively, during a follow-up period of 3.5±2.2 years. Variables associated with HCC recurrence on multivariate analysis were α-fetoprotein more than 100 ng/ml (HR=5.6, P=0.001) and tumor beyond Up-to-7 imaging criteria (HR=6.3, P=0.001). Bootstrap validation showed that overfitting was negligible. Scoring points were assigned as follows (0-2 points): pre-LT α-fetoprotein more than 100 ng/ml (presence=1 point, absence=0 point), and tumor beyond Up-to-7 imaging criteria (presence=1 point, absence=0 point). AUROC curve indicated a c-statistic of 0.74 (0.58-0.88, P=0.003). Two distinct subgroups of patients were identified with a cut-off more than or equal to 1 point (62% sensitivity and 82% specificity): low risk (0 point) and high risk (1-2 points). The 5-year recurrence rate was 9.4 and 44.5% (P=0.0001) and the 5-year overall survival was 78.1 and 34.8% (P=0.0001) in the low-risk and high-risk groups, respectively.

CONCLUSION

This scoring model may be a useful additional tool for HCC recurrence risk stratification before LT. Prospective studies are needed to evaluate our model.

Development of a circulating tumor cells based RNA in situ hybridization technique

AIM: To develop a circulating tumor cells (CTCs) based RNA in situ hybridization technique for analyzing CTC phenotype and indirectly detecting tumor progression.

METHODS: We adopted the negative enrichment method to obtain slides of peripheral blood CTC and nucleated cells of hepatocellular carcinoma patients, and then RNA ISH on CTC slides was then developed. The peptidyl-prolyl cis-trans isomerase B (PPIB) gene, which is highly conserved in eukaryotes, was used as a positive control probe, which can detect the PPIB gene transcriptional activity on CTC slides.

RESULTS: The negative enrichment method allowed for successful isolation of peripheral blood CTCs from hepatocellular carcinoma patients. However, on CTC and nucleated cell slides which were fixed by conventional methods, RNA in situ hybridization signal was very weak. We tested the reagents used in negative enrichment, which showed that the reagents had no influence on the cells. Finally, we got the transcriptional information of PPIB on CTC slides after adjusting the conventional fixing method and time, and provided scientific data for real-time dynamic monitoring specific gene expression in peripheral blood CTCs of patients with solid tumors.

CONCLUSION: Shortening the time between blood collection and cell fixation can improve RNA degradation. On more than 10 slides of peripheral nucleated blood cells isolated by negative enrichment, real-time monitoring of CTC specific gene transcription level can be achieved through a high sensitive RNA in situ hybridization technique.

Reassessing the boundaries of liver transplantation for hepatocellular carcinoma: Where do we stand with tumor down-staging?

Down-staging of hepatocellular carcinoma prior to liver transplantation (LT) has generated a lot of interest in recent years and has been identified in two recent national conferences on hepatocellular carcinoma as one of the priorities for research. Down-staging is defined as reduction in the tumor burden using local regional therapy specifically to meet acceptable criteria for LT. The rationale behind down-staging of tumors initially exceeding conventional criteria for LT is to select a subgroup of tumors with favorable biology and prognosis for LT as assessed by their response to local regional therapy. The expectation is to achieve comparable posttransplant survival between patients who achieve successful tumor down-staging before LT and those whose tumors meet LT criteria at the outset without needing down-staging. The application of tumor down-staging requires a highly structured approach using a treatment protocol that includes five essential components: eligibility criteria, down-staging endpoints, selection of the type of local regional therapy, minimal observation period from successful tumor down-staging to LT, and criteria for treatment failure and exclusion from LT. This review article summarizes published data on down-staging and addresses key questions related to each of the components of the down-staging protocol as well as treatment efficacy.

CONCLUSION

Based on a review of published data and recommendations from recent national and international conferences on hepatocellular carcinoma and LT, a standardized down-staging protocol is proposed to further evaluate the feasibility and efficacy of applying tumor down-staging on a broader scale.

Prediction of hepatocellular carcinoma biological behavior in patient selection for liver transplantation

Morphological criteria have always been considered the benchmark for selecting hepatocellular carcinoma (HCC) patients for liver transplantation (LT). These criteria, which are often inappropriate to express the tumor’s biological behavior and aggressiveness, offer only a static view of the disease burden and are frequently unable to correctly stratify the tumor recurrence risk after LT. Alpha-fetoprotein (AFP) and its progression as well as AFP-mRNA, AFP-L3%, des-γ-carboxyprothrombin, inflammatory markers and other serological tests appear to be correlated with post-transplant outcomes. Several other markers for patient selection including functional imaging studies such as ¹⁸F-FDG-PET imaging, histological evaluation of tumor grade, tissue-specific biomarkers, and molecular signatures have been outlined in the literature. HCC growth rate and response to pre-transplant therapies can further contribute to the transplant evaluation process of HCC patients. While AFP, its progression, and HCC response to pre-transplant therapy have already been used as a part of an integrated prognostic model for selecting patients, the utility of other markers in the transplant setting is still under investigation. This article intends to review the data in the literature concerning predictors that could be included in an integrated LT selection model and to evaluate the importance of biological aggressiveness in the evaluation process of these patients.

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.

Timing of Antiviral Therapy in Candidates for Liver Transplant for Hepatitis C and Hepatocellular Carcinoma

OBJECTIVES

Hepatitis C virus infection is the most common underlying reason for hepatocellular carcinoma and indication for liver transplant. The increased availability of non-interferon-based therapy has expanded the number of treatment-eligible patients.

MATERIALS AND METHODS

We used a decision analysis model to compare 2 strategies of treating hepatitis C virus. Included patients were followed for 1 year after liver transplant. The probabilities and costs were obtained from a literature review, an expert panel, and our institution's experience. Sensitivity analyses were performed on all variables.

RESULTS

Our model demonstrated that it would be less costly to treat patients after liver transplant than to treat patients while they wait for transplant. When we compared baseline values, the cost difference between the 2 strategies was $25,011 per patient and $41,535 per sustained viral response. Overall survival was 60.1% for both strategies. Our model was robust across most of the variables tested in the sensitivity analysis.

CONCLUSIONS

Our results indicated that there is no substantial pharmacoeconomic or survival advantage of treating hepatitis C virus in patients with compensated cirrhosis and hepatocellular carcinoma before liver transplant versus after transplant.

Liver transplantation for hepatocellular carcinoma - factors influencing outcome and disease-free survival

Hepatocellular carcinoma is one of the leading causes of cancer-related death worldwide. Liver transplantation can be a curative treatment in selected patients. However, there are several factors that influence disease-free survival after transplantation. This review addresses the pre-, intra- and postoperative factors that influence the risk of tumor recurrence after liver transplantation.

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.

Managements of recurrent hepatocellular carcinoma after liver transplantation: A systematic review

AIM: To investigate the efficacy (survival) and safety of treatments for recurrent hepatocellular carcinoma (HCC) in liver transplantation (LT) patients.

METHODS: Literature search was performed on available online databases without a time limit until January 2015. Clinical studies describing survival after HCC recurrence in LT patients were retrieved for a full-text evaluation. A total of 61 studies were selected: 13 case reports, 41 retrospective case series, and 7 retrospective comparative studies.

RESULTS: Based on all included studies, the mean HCC recurrence rate was 16% of all LTs for HCC. A total of 1021 LT patients experienced HCC recurrence. The median time from LT to HCC recurrence was 13 mo (range 2-132 mo). The majority of patients (67%) presented with HCC extra-hepatic recurrences, involving lung, bone, adrenal gland, peritoneal lymph nodes, and rarely the brain. Overall survival after HCC recurrence was 12.97 mo. Surgical resection of localized HCC recurrence and Sorafenib for controlling systemic spread of HCC recurrence were associated with the higher survival rates (42 and 18 mo, respectively). However, Sorafenib, especially when combined with mTOR, was frequently associated with severe side effects that required dose reduction or discontinuation

CONCLUSION: Management of recurrent HCC in LT patients is challenging and associated with poor prognosis independently of the type of treatment.

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.

Total tumor volume and alpha-fetoprotein for selection of transplant candidates with hepatocellular carcinoma: A prospective validation

The selection of liver transplantation (LT) candidates with hepatocellular carcinoma (HCC) is currently validated based on Milan criteria. The use of extended criteria has remained a matter of debate, mainly because of the absence of prospective validation. The present prospective study recruited patients according to the previously proposed total tumor volume (TTV; ≤115 cm(3) )/alpha-fetoprotein (AFP; ≤400 ng/mL) score. Patients with AFP >400 ng/mL were excluded, and, as such, the Milan group was modified to include only patients with AFP <400 ng/mL; these patients were compared to patients beyond Milan, but within TTV/AFP. From January 2007 to March 2013, 233 patients with HCC were listed for LT. Of them, 195 patients were within Milan and 38 beyond Milan, but within TTV/AFP. The average follow-up from listing was 33.9 ± 24.9 months. Risk of dropout was higher for patients beyond Milan, but within TTV/AFP (16 of 38; 42.1%), than for those within Milan (49 of 195 [25.1%]; P = 0.033). In parallel, intent-to-treat survival from listing was lower in patients beyond Milan (53.8% vs. 71.6% at 4 years; P < 0.001). After a median waiting time of 8 months, 166 patients were transplanted, 134 within Milan criteria, and 32 beyond Milan but within TTV/AFP. They demonstrated acceptable and similar recurrence rates (4.5% vs. 9.4%; P = 0.138) and post-transplant survivals (78.7% vs. 74.6% at 4 years; P = 0.932).

CONCLUSION

Based on the present prospective study, HCC LT candidate selection could be expanded to the TTV (≤115 cm(3) )/AFP (≤400 ng/mL) criteria in centers with at least 8-month waiting time. An increased risk of dropout on the waiting list can be expected, but with equivalent and satisfactory post-transplant survival.

Validation of a criteria-specific long-term survival prediction model for hepatocellular carcinoma patients after liver transplantation

The aim of this study was to validate a criteria-specific long-term survival prediction model (MHCAT) in a large cohort of hepatocellular carcinoma (HCC) patients after liver transplantation (LT) in China. Independent risk factors in MHCAT were retrospectively analysed for HCC patients recorded in the China Liver Transplant Registry. Survival predictions for each patient were calculated using MHCAT scores and the Metroticket formula separately, and the prediction efficacy of MHCAT and Metroticket was compared using the area under ROC curve (c-statistic). A total of 1371 LTs for HCC were analysed in the study, with a median follow-up of 22.2 months (IQR 6.1–72.4 months). The proportions meeting the Milan, UCSF, Fudan and Hangzhou criteria were 34.4%, 39.7%, 44.2% and 51.9%, respectively. The c-statistics for MHCAT predictions of 3- and 5-year survival rates of HCC recipients were 0.712–0.727 and 0.726–0.741, respectively. Among these patients, 1298 LTs for HCC were ultimately selected for the comparison analysis for prediction efficacy. The c-statistic of MHCAT for predictions of 3-year survival with reference to the Milan, UCSF and Fudan criteria was significantly increased compared with that for Metroticket (p < 0.05). In conclusion, MHCAT can effectively predict long-term survival for HCC recipients after LT.

miR-744 is a potential prognostic marker in patients with hepatocellular carcinoma

Identification of new biomarkers for aggressiveness of hepatocellular carcinoma (HCC) to supplement the current group of prognosis algorithms is a significant clinical need. To clarify expression levels of microRNA-744 (miR-744) in HCC tissues and to explore its clinicopathological significance in HCC patients following liver transplantation (LT), we quantified miR-744 using real-time quantitative reverse transcription polymerase chain reaction in 96 paired cancerous tissues and para-cancerous normal liver tissues. We investigated relationships among miR-744 expression, clinicopathological parameters, and overall survival (OS). Of 96 paired samples, 68 cancer tissues expressed low miR-744 compared with their matched normal liver tissues. Patients with microvascular invasion or multi-tumor nodules showed significantly lower miR-744 expression; miR-744 was further decreased in patients with post-LT HCC recurrence compared with non-recurring patients. Patients with lower miR-744 expression showed significantly poorer recurrence-free survival and OS than individuals with higher miR-744 levels. Multivariate analysis revealed that lower miR-744 was an independent predictor of poor prognosis. Our results associate decreased miR-744 expression with HCC recurrence and prognosis, and also suggest that miR-744 is an independent predictor of survival in HCC patients after LT and may therefore be a potential biomarker for their prognosis.

Current strategies for preventing the recurrence of hepatocellular carcinoma after liver transplantation

BACKGROUND

Liver transplantation is the optimal treatment for a selected group of patients with moderate to severe cirrhosis and hepatocellular carcinoma (HCC). Despite the strict selection of candidates, post-transplant recurrence often occurs and markedly reduces the long-term survival of patients with HCC. The present review focuses on the current strategies on preventing the recurrence of HCC after liver transplantation.

DATA SOURCES

Relevant articles were identified by extensive searching of PubMed using the keywords "hepatocellular carcinoma", "recurrence" and "liver transplantation" between January 1996 and January 2014. Additional papers were searched manually from the references in key articles.

RESULTS

The current theories of HCC recurrence after liver transplantation are: (i) the growth of pre-transplant occult metastases; (ii) the engraftment of circulating tumor cells released at the time of transplantation. Pre-transplant treatment aims to control local tumor by radiofrequency ablation, transarterial embolization and transarterial chemoembolization. The main objective during the operation is to prevent tumor cell dissemination. Post-transplant treatment includes systemic anticancer therapy, antiviral therapy, and most recently, immunotherapy. These strategies concentrate on the control of the tumor when the patients are waiting for transplant, to reduce the release of HCC cells during surgical procedures and to clear the occult HCC cells after transplantation.

CONCLUSIONS

Much can be done to prevent HCC recurrence after liver transplantation. In future, effort is likely to be directed towards combining multidisciplinary approaches and various treatment modalities.

Toward a better liver graft allocation that accounts for candidates with and without hepatocellular carcinoma

In some countries where the Model for End-Stage Liver Disease (MELD) score is used for graft allocation, selected patients with hepatocellular carcinoma (HCC) receive a fixed number of exception points at listing, and increasing priority on the list by accruing additional exception points at regular time intervals. This system originally aimed at balancing the risks of HCC patients of developing contraindications and of non-HCC patients of dying before transplantation, is not ideal because it appears to offer an advantage to HCC patients, regardless of tumor characteristics and response to loco-regional treatment. Scores modulated by HCC characteristics have been proposed. They are based on a more refined estimate of the risk of pretransplant drop-out or of the posttransplant transplant benefit expressed as the life-years gained for each graft. This review describes the newly proposed systems, and discusses their advantages and drawbacks. We believe that the current exception points allocation should be revised and that drop-out-equivalent or transplant benefit-equivalent models should be studied further. As with all policy changes, these should be done under close monitoring that allows subsequent revisions.

Pre-retrieval reperfusion decreases cancer recurrence after rat ischemic liver graft transplantation

BACKGROUND & AIMS

Liver transplantation from marginal donors is associated with ischemia/reperfusion (I/R) lesions, which may increase the risk of post-transplant hepatocellular carcinoma (HCC) recurrence. Graft reperfusion prior to retrieval (as for extracorporeal membrane oxygenation--ECMO) can prevent I/R lesions. The impact of I/R on the risk of cancer recurrence was assessed on a syngeneic Fischer-rat liver transplantation model.

METHODS

HCC cells were injected into the vena porta of all recipients at the end of an orthotopic liver transplantation (OLT). Control donors were standard heart-beating, ischemic ones (ISC), underwent 10 min or 30 min inflow liver clamping prior to retrieval, and ischemic/reperfused (ISC/R) donors underwent 2h liver reperfusion after the clamping.

RESULTS

I/R lesions were confirmed in the ISC group, with the presence of endothelial and hepatocyte injury, and increased liver function tests. These lesions were in part reversed by the 2h reperfusion in the ISC/R group. HCC growth was higher in the 10 min and 30 min ISC recipients (p = 0.018 and 0.004 vs. control, as assessed by MRI difference between weeks one and two), and was prevented in the ISC/Rs (p = 0.04 and 0.01 vs. ISC). These observations were associated with a stronger pro-inflammatory cytokine profile in the ISC recipients only, and the expression of hypoxia and HCC growth-enhancer genes, including Hmox1, Hif1a and Serpine1.

CONCLUSIONS

This experiment suggests that ischemia/reperfusion lesions lead to an increased risk of post-transplant HCC recurrence and growth. This observation can be reversed by graft reperfusion prior to retrieval.

Hepatocellular cancer: how to expand safely inclusion criteria for liver transplantation

PURPOSE OF REVIEW

The Milan criteria are still considered to be the best ones to select patients with hepatocellular cancer (HCC) for liver transplantation. Although the Milan criteria allowed lowering the incidence of tumor recurrence to a remarkable 10%, there is growing evidence that high numbers of patients were unrightfully excluded from a curative liver transplantation when exceeding these criteria. New strategies have been advocated during recent years with the intent not only to enlarge the number of potential transplant candidates, but also to select recipients with the lowest biological risk of recurrence.

RECENT FINDINGS

Different 'biological' and 'dynamic' parameters have been proposed both in western and eastern scenarios, such as α-fetoprotein dynamics, radiological response to locoregional treatments and several inflammatory markers, the neutrophil-to-lymphocyte ratio being the most promising one.

SUMMARY

The paradigm that HCC patients should be selected according to morphological aspects (tumor numbers and diameters) only, based on the almost 20-year old success story of the Milan criteria, should be modified by combining these parameters with newer biological tumor markers in order to further refine the selection for liver transplantation. Such therapeutic algorithm will allow to further improve selection for and thus outcome after liver transplantation for HCC patients.

Accurate computed tomography-based portal pressure assessment in patients with hepatocellular carcinoma

BACKGROUND & AIMS

Liver resection is generally restricted to patients without clinically significant portal hypertension (Hepatic Venous Pressure Gradient - HVPG - ⩽10mmHg) and several teams perform transjugular HVPG measurements as part of the pre-operative work-up. The present study investigates whether a non-invasive Computed Tomography (CT)-based assessment could be as accurate as the invasive transjugular measurement.

METHODS

A cohort of patients with hepatocellular carcinoma (HCC) treated by resection (n=36) or transplantation (n=39) was selected (mean age: 61±9.2years, male/female ratio: 4/1). Pre-operative CTs were read by two independent investigators, and potential CT-based HVPG predictors were compared to the transjugular HVPG measurements. A validation was conducted on another cohort of 70 non-surgical patients.

RESULTS

The invasive HVPG values were significantly correlated to liver/spleen volume ratio, spleen volume, platelet count, and peri-hepatic ascites (p<0.001), which all showed high inter-observer agreements (intra-class correlation coefficients ⩾0.927, Kappa ⩾0.945). The presence of a HVPG >10mmHg was best predicted by the liver/spleen volume ratio (AUC: 0.883 [0.805-0.960]) and the peri-hepatic ascites (p<0.001). These two variables were combined into an accurate model for predicting HVPG >10mmHg (AUC: 0.911 [0.847-0.975]), with sensitivity, specificity, and positive and negative predictive values of 92%, 79%, 91%, and 81%. The model was also accurate in the validation cohort with an AUC of 0.820 [0.719-0.921]. The computed formula was:

CONCLUSIONS

The proposed CT-based model showed a high accuracy in the prediction of HVPG and, if further confirmed by prospective validation, could replace the invasive transjugular assessment in patients not requiring a biopsy of the non-tumoral liver.

Alloimmune activation promotes anti-cancer cytotoxicity after rat liver transplantation

Liver transplantation for hepatocellular carcinoma (HCC) results in a specific condition where the immune response is potentially directed against both allogeneic and cancer antigens. We have investigated the level of anti-cancer immunity during allogeneic immune response. Dark Agouti-to-Lewis and Lewis-to-Lewis rat liver transplantations were performed and the recipients anti-cancer immunity was analysed at the time of alloimmune activation. The occurrence of rejection in the allogeneic recipients was confirmed by a shorter survival (p<0.01), increased liver function tests (p<0.01), the presence of signs of rejection on histology, and a donor-specific ex vivo mixed lymphocyte reaction. At the time of alloimmune activation, blood mononuclear cells of the allogeneic group demonstrated increased anti-cancer cytotoxicity (p<0.005), which was related to an increased natural killer (NK) cell frequency (p<0.05) and a higher monocyte/macrophage activation level (p<0.01). Similarly, liver NK cell anti-cancer cytotoxicity (p<0.005), and liver monocyte/macrophage activation levels (p<0.01) were also increased. The alloimmune-associated cytotoxicity was mediated through the NKG2D receptor, whose expression was increased in the rejected graft (p<0.05) and on NK cells and monocyte/macrophages. NKG2D ligands were expressed on rat HCC cells, and its inhibition prevented the alloimmune-associated cytotoxicity. Although waiting for in vivo validation, alloimmune-associated cytotoxicity after rat liver transplantation appears to be linked to increased frequencies and levels of activation of NK cells and monocyte/macrophages, and is at least in part mediated through the NKG2D receptor.

Endothelial transdifferentiation in hepatocellular carcinoma: loss of Stabilin-2 expression in peri-tumourous liver correlates with increased survival

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) is a malignant tumour that is characterized by extensive vascular remodelling and responsiveness to treatment with the anti-angiogenic multikinase inhibitor sorafenib. The aim was to study endothelial remodelling in HCC.

METHODS

The murine inducible albumin-SV40-large T-antigen model and two tissue microarrays (TMA) with 295 tumourous and 83 peri-tumourous samples of 296 patients with HCC were analysed for expression of liver sinusoidal endothelial cell (LSEC)-specific marker proteins, stabilin-1 and stabilin-2, LYVE-1 and CD32b.

RESULTS

LSEC marker proteins were sequentially lost during HCC progression in the murine HCC model being absent from tumour nodules larger than 800 μm in diameter. Similarly, the TMA analysis of human HCCs revealed loss of all four marker proteins in the majority of tumourous tissue samples. Preservation of LYVE-1 expression showed a significant correlation with low grading (G1). In corresponding peri-tumourous liver tissue, loss of all marker proteins was seen in a minor proportion of cases (34%) while the majority of cases retained expression of at least one of the marker proteins. Loss of stabilin-2 expression in peri-tumourous liver tissue of patients with HCC was significantly less likely to occur (38%) than loss of the other marker proteins (63-95%) and it was associated with significantly longer tumour-specific (P = 0.0523) and overall (P = 0.0338) survival. Loss of stabilin-2 may enhance survival in HCC by preventing endothelial-tumour cell adhesive interactions and microvascular invasion.

CONCLUSIONS

In summary, endothelial transdifferentiation is a major pathogenic event in HCC development indicating a switch from vessel co-option/intussusceptive angiogenesis to sprouting angiogenesis.

Additive effect of sirolimus and anti-death receptor 5 agonistic antibody against hepatocellular carcinoma

BACKGROUND & AIMS

Despite careful patient selection, hepatocellular carcinoma (HCC) recurs in 10-20% of cases after liver transplantation, and the use of potent adjuvant anticancer drugs would be welcome. The aim of this study was to evaluate the efficiency of a combined therapy of rapamycin (sirolimus) and anti-death receptor (DR)5 monoclonal antibody (mAb) on HCC.

METHODS

We first assessed the side effects of anti-DR5 mAb administration in vivo by giving various doses of anti-DR5 mAb. Cell proliferation assays were then performed using mouse Hepa1-6 cells or human Huh7 cells to quantify the relative cell viability under various concentrations of sirolimus, anti-DR5 mAb or a combination. Next, one million Hepa1-6 cells were transplanted into C.B17-SCID-beige mice subcutaneously, and four groups were created: (1) untreated, (2) anti-DR5 mAb alone, (3) sirolimus alone and (4) anti-DR5 mAb + sirolimus.

RESULTS

Anti-DR5 mAb (200 and 300 μg/day) induced liver dysfunction with partial necrosis of the liver, but 100 μg/day was well tolerated with transaminitis, but normal bilirubin and only minor histological liver damage. In vitro, anti-DR5 mAb lysed Hepa1-6 and Huh7 cells in a dose-dependent manner, and combinations of sirolimus and anti-DR5 mAb demonstrated an additive effect. In vivo studies demonstrated that tumour sizes were significantly smaller in the combined therapy group than in the monotherapy groups.

CONCLUSIONS

Combining sirolimus and low-dose anti-DR5 mAb has a significant effect against HCC. This strategy represents a potential novel approach for the management of HCC.

Factors predicting survival after post-transplant hepatocellular carcinoma recurrence

BACKGROUND

Although factors associated with an increased risk of recurrence after liver transplantation for hepatocellular carcinoma (HCC) have been extensively studied, the history of patients with a post-transplant recurrence is poorly known.

METHODS

Patients experiencing a post-transplant HCC recurrence from 1996 to 2011 in two transplant programs were included. Demographic, transplant, and post-recurrence variables were assessed.

RESULTS

Thirty patients experienced an HCC recurrence-22 men and 8 women with a mean age of 55 ± 6 years. Sixteen (53 %) were outside the Milan criteria at the time of transplantation. Most recurrences (60 %) appeared within the first 18 months after transplantation, ranging between 1.7 and 109 months (median 14.2 months). Mean post-recurrence survival was 33 ± 31 months. On univariate analysis, total tumor volume (TTV; p = 0.047), microvascular invasion (p = 0.011), and time from transplant to recurrence (p = 0.001) predicted post-recurrence survival. On multivariate analysis, both time from transplant to recurrence (p = 0.001) and history of rejection (p = 0.043), but not the location of the recurrence or the type of recurrence treatment, predicted post-recurrence survival.

CONCLUSION

This study suggests that patients with early post-transplant HCC recurrence have worse outcomes. Those with a history of graft rejection have better survivals, possibly due to more active anti-cancer immunity.

The mTOR pathway in hepatic malignancies

The mechanistic/mammalian target of rapamycin (mTOR) pathway plays a critical role in cellular metabolism, growth, and proliferation and has been evaluated as a target for therapy in various malignancies. The mTOR pathway is a major tumor-initiating pathway in hepatocellular carcinoma, with up-regulation seen in up to 50% of tumors. Metformin, which represses mTOR signaling by activating adenosine monophosphate-activated protein kinase, has been shown to decrease liver carcinogenesis in population studies. mTOR inhibitors such as everolimus have been evaluated as adjunctive chemotherapy with some success, although efficacy has been limited by the lack of complete mTOR pathway inhibition. The active site mTOR inhibitors hold greater promise, given that they offer complete mTOR suppression. There is also evidence of mTOR pathway activation in cholangiocarcinoma, although its biological significance in initiating and promoting tumor progression remains ambiguous. This review provides an overview of the complex biochemistry behind the mTOR pathway and its role in carcinogenesis, especially as it pertains to hepatic malignancies.

Pre-liver transplant biopsy in hepatocellular carcinoma: a potential criterion for exclusion from transplantation?

BACKGROUND

In cirrhotic patients with hepatocellular carcinoma (HCC), poor differentiation in pre-liver transplantation (LT) biopsy of the largest tumour is used as a criterion for exclusion from LT in some centres. The potential role of pre-LT biopsy at one centre was explored.

METHODS

A prospective database of patients undergoing orthotopic LT for radiologically diagnosed HCC at St James's University Hospital, Leeds during 2006-2011 was analysed.

RESULTS

A total of 60 predominantly male (85.0%) patients with viral hepatitis were identified. There were discrepancies between radiological and histopathological findings with respect to the number of tumours identified (in 27 patients, 45.0%) and their size (in 63 tumours, 64.3%). In four (6.7%) patients, the largest lesion, which would theoretically have been targeted for biopsy, was not the largest in the explant. Nine (31.0%) patients with multifocal HCC had tumours of differing grades. In two (6.9%) patients, the largest tumour was well differentiated, but smaller tumours in the explant were poorly differentiated. In one patient, the largest lesion was benign and smaller invasive tumours were confirmed histologically.

CONCLUSIONS

The need to optimize selection for LT in HCC remains. In the present series, the largest tumour was not always representative of overall tumour burden or biological aggression and its potential use to exclude patients from LT is questionable.

Immune modulation of effector CD4+ and regulatory T cell function by sorafenib in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a difficult to treat cancer characterized by poor tumor immunity with only one approved systemic drug, sorafenib. If novel combination treatments are to be developed with immunological agents, the effects of sorafenib on tumor immunity are important to understand. In this study, we investigate the impact of sorafenib on the CD4+CD25- effector T cells (Teff) and CD4+CD25+ regulatory T cells (Tregs) from patients with HCC. We isolated Teff and Treg from peripheral mononuclear cells of HCC patients to determine immune reactivity by thymidine incorporation, ELISA and flow cytometry. Teff cultured alone or with Treg were supplemented with different concentrations of sorafenib. The effects of sorafenib on Teff responses were dose-dependent. Pharmacologic doses of sorafenib decreased Teff activation by down regulating CD25 surface expression. In contrast, sub-pharmacologic concentrations of sorafenib resulted in Teff activation. These low doses of sorafenib in the Teff cultures led to a significant increase in Teff proliferation, IL2 secretion and up-regulation of CD25 expression on the cell surface. In addition, low doses of sorafenib in the suppression Teff/Treg cocultures restored Teff responses by eliminating Treg suppression. The loss of Treg suppressive function correlated with an increase in IL2 and IL6 secretion. Our findings show that sub-pharmacologic doses of sorafenib impact subsets of T cells differently, selectively increasing Teff activation while blocking Treg function. In conclusion, this study describes novel immune activating properties of low doses of sorafenib by promoting immune responsiveness in patients with HCC.

Developments in liver transplantation for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a serious health problem worldwide because of its association with hepatitis B and C viruses. In this setting, liver transplantation (LT) has become one of the best treatments since it removes both the tumor and the underlying liver disease. Due to the improvement of imaging techniques and surveillance programs, HCC are being detected earlier at a stage at which effective treatment is feasible. The prerequisite for long term success of LT for HCC depends on tumor load and strict selection criteria with regard to the size and number of tumor nodules. The need to obtain the optimal benefit from the limited number of organs available has prompted the maintenance of selection criteria in order to list only those patients with early HCC who have a better long-term outcome after LT. The indications for LT and organ allocation system led to many controversies around the use of LT in HCC patients. This review aims at giving the latest updated developments in LT for HCC focusing on selection criteria, diagnostic tools, prognostic factors, treatment on the waiting list, role of living donor liver transplantation and adjuvant therapy, and the impact of immunosuppression on HCC recurrence after LT.

Circulating tumor cells in hepatocellular carcinoma: detection techniques, clinical implications, and future perspectives

Hepatocellular carcinoma (HCC) is a primary liver cancer with a huge challenge in terms of its complex etiology and its management. The fact that the most common site of early tumor recurrence in liver transplantation for HCC is the transplanted allograft strongly suggests that circulating tumor cells (CTCs) are really an active source of HCC metastasis or recurrence. In the past decade, with the tremendous progress in the technology of CTC detection, there is convincing evidence that CTCs have great potential as a marker for metastatic disease and poor prognosis in patients with a malignancy. Currently some interesting and encouraging results have been achieved in HCC CTC detection, although the knowledge about its clinical relevance in HCC is lagging behind other major tumor types. Here we will review existing and developing methodologies for CTC detection, discuss future perspectives, and describe the potential clinical impact of the identification and molecular characterization of CTC subset or circulating cancer stem cells in HCC patients. Particular attention is given to the results based on the HCC CTC study.

New concepts and best practices for management of pre- and post-transplantation cancer

Solid-organ transplant recipients are at increased risk of developing cancer compared with the general population. Tumours can arise de novo, as a recurrence of a preexisting malignancy, or from the donated organ. The ATOS (Aula sobre Trasplantes de Órganos Sólidos; the Solid-Organ Transplantation Working Group) group, integrated by Spanish transplant experts, meets annually to discuss current advances in the field. In 2011, the 11th edition covered a range of new topics on cancer and transplantation. In this review we have highlighted the new concepts and best practices for managing cancer in the pre-transplant and post-transplant settings that were presented at the ATOS meeting. Immunosuppression plays a major role in oncogenesis in the transplant recipient, both through impaired immunosurveillance and through direct oncogenic activity. It is possible to transplant organs obtained from donors with a history of cancer as long as an effective minimization of malignancy transmission strategy is followed. Tumour-specific wait-periods have been proposed for the increased number of transplantation candidates with a history of malignancy; however, the patient's individual risk of death from organ failure must be taken into consideration. It is important to actively prevent tumour recurrence, especially the recurrence of hepatocellular carcinoma in liver transplant recipients. To effectively manage post-transplant malignancies, it is essential to proactively monitor patients, with long-term intensive screening programs showing a reduced incidence of cancer post-transplantation. Proposed management strategies for post-transplantation malignancies include viral monitoring and prophylaxis to decrease infection-related cancer, immunosuppression modulation with lower doses of calcineurin inhibitors, and addition of or conversion to inhibitors of the mammalian target of rapamycin.

Liver transplantation for hepatocellular cancer: UCL experience in 137 adult cirrhotic patients. Alpha-foetoprotein level and locoregional treatment as refined selection criteria

Liver transplantation (LT) is a validated treatment for selected cirrhotics with hepatocellular cancer (HCC). A retrospective single center study including 137 recipients having proven HCC was done to refine inclusion criteria for LT as well as to look at impact of locoregional treatment (LRT) on outcome. At pre-LT imaging, 42 (30.6%) patients were Milan criteria (MC)-OUT; 28 (20.4%) were University of California San Francisco criteria (UCSFC)-OUT. Pre-LT LRT was performed in 109 (79.6%) patients. Multivariate analysis identified four factors to be independently predictive of recurrence: tumour number >3, AFP level ≥400 ng/ml, microvascular invasion and rejection needing anti-lymphocytic antibodies. When considering pre-transplant variables only, AFP level ≥400 ng/ml (HR = 5.13; P < 0.0001) was the unique risk factor for recurrence; conversely, application of LRT was protective (HR = 0.42; P = 0.04). MC-IN patients having LRT (n = 79) had the best 5-year tumour-free survival (TFS) (91.6%). MC-IN patients without LRT (n = 16) and MC-OUT patients with LRT (n = 30) had similar good TFS (72.7% vs.77.5%); finally MC-OUT patients without LRT (n = 12) had the worst results (45.0%; vs. 1st group: P < 0.0001). Immediate pre-LT AFP and aggressive pre-transplant LRT strategy, especially in MC-OUT patients, are both important elements to further expand inclusion criteria without compromising long-term results of HCC liver recipients.

Adhesion receptors as therapeutic targets for circulating tumor cells

Metastasis contributes to >90% of cancer-associated mortality. Though primary tumors can be removed by surgical resection or chemo/radiotherapy, metastatic disease is a great challenge to treatment due to its systemic nature. As metastatic “seeds,” circulating tumor cells (CTCs) are believed to be responsible for dissemination from a primary tumor to anatomically distant organs. Despite the possibility of physical trapping of CTCs in microvessels, recent advances have provided insights into the involvement of a variety of adhesion molecules on CTCs. Such adhesion molecules facilitate direct interaction with the endothelium in specific tissues or indirectly through leukocytes. Importantly, significant progress has been made in understanding how these receptors confer enhanced invasion and survival advantage during hematogenous circulation of CTCs through recruitment of macrophages, neutrophils, platelets, and other cells. This review highlights the identification of novel adhesion molecules and how blocking their function can compromise successful seeding and colonization of CTCs in new microenvironment. Encouraged by existing diagnostic tools to identify and isolate CTCs, strategic targeting of these adhesion molecules to deliver conventional chemotherapeutics or novel apoptotic signals is discussed for the neutralization of CTCs in the circulation.

Advances in understanding clinical significance of circulating tumor cells and cell-free DNA methylation in patients with hepatocellular carcinoma

During the early formation and growth of a primary tumor, tumor cells can be detached from the primary tumor and circulate through the bloodstream to form circulating tumor cells (CTCs). Also during the early stage of tumor development, apoptotic and necrotic tumor cells can release DNA into the bloodstream to form circulating cell-free DNA. Therefore, analysis of CTCs and circulating cell-free DNA is considered as a real-time "liquid biopsy" for cancer patients. CTCs are very heterogeneous and can be enriched and detected using different technologies based on their physical and biological properties. The use of modern molecular biological techniques to extract the cell-free DNA in circulating blood and detect aberrant genetic and epigenetic alterations can provide valuable information for the early diagnosis, prediction of response to therapy, recurrence monitoring and prognosis evaluation in cancer patients. In this paper, we will give a review of recent advances in understanding the clinical significance of CTCs and cell-free DNA in patients with hepatocellular carcinoma.

Liver Transplantation for HCC: A Review

Hepatocellular carcinoma (HCC) often occurs in patients with chronic liver disease or cirrhosis. Liver transplantation for hepatocellular carcinoma has the potential to eliminate both the tumor as well as the underlying cirrhosis and is the ideal treatment for HCC in cirrhotic liver as well as massive HCC in noncirrhotic liver. Limitations in organ availability, necessitate stringent selection of patients who would likely to derive most benefit. Selection criteria have considered tumor size, number, volume as well as biological features. The Milan criteria set the benchmark for tumors that would benefit from liver transplantation but were found to be excessively restrictive. Modest expansion in criteria has also been shown to be associated with equivalent survival. Microvascular invasion is the single most important adverse prognostic factor for survival. Living donor liver transplantation has expanded donor options and has the advantage of lower waiting period and not impacting the non-HCC waiting list. Acceptable outcomes have been obtained with living donor liver transplantation for larger and more numerous tumors in the absence of microvascular invasion. Downstaging of tumors to prevent progression while waiting for an organ or for reduction in size to allow enrolment for transplantation has met with variable success.