Evolving thresholds for liver transplantation in hepatocellular carcinoma: A Western experience

Biliary stenosis after liver transplant is not associated with cytomegalovirus infection

Background

Liver transplantation (LT) is the best treatment for end-stage liver disease; however, biliary complications (BCs) still pose a significant challenge. Among the post-transplant BC, strictures and biliary fistulas are the most common. Biliary strictures are classified as anastomotic and non-anastomotic. Some previous studies suggest an association between post-transplant biliary strictures and cytomegalovirus (CMV) infection. In this study, we aimed to identify whether there is an association between CMV infection and biliary strictures in patients undergoing LT.

Methods

A retrospective study of 175 patients aged ≥18 years undergoing LT at Felicio Rocho Hospital between 2011 and 2017 was conducted. All included patients received grafts perfused with Institut Georges Lopez-1 (IGL-1) solution from brain-dead donors, survived post-transplantation for more than 120 days, and had a minimum follow-up of 12 months after LT. The diagnosis of CMV was made by antigenemia and biliary strictures by magnetic resonance cholangiopancreatography (MRCP).

Results

The average age of the recipients was 54 years. Postoperative BCs occurred in 12% of transplants. The most common BC was stricture (9.1%), with a predominance of anastomotic strictures (AS) over non-AS (NAS) (87.5% vs. 12.5%, respectively). CMV infection was confirmed in 22.9% of patients. In the univariate analysis, post-transplant CMV infection correlated with the development of BCs (P=0.01), as well as biliary strictures (P=0.008). In the multivariate analysis, however, only model for end-stage liver disease (MELD) >21 was a risk factor for the development of BCs in general (P=0.02) and biliary strictures (P=0.01).

Conclusions

CMV infection was not an independent risk factor for the development of non-anastomotic post-transplant biliary strictures in this study.

Continuous Risk Score Predicts Waitlist and Post-transplant Outcomes in Hepatocellular Carcinoma Despite Exception Changes

BACKGROUND & AIMS

Continuous risk-stratification of candidates and urgency-based prioritization have been utilized for liver transplantation (LT) in patients with non-hepatocellular carcinoma (HCC) in the United States. Instead, for patients with HCC, a dichotomous criterion with exception points is still used. This study evaluated the utility of the hazard associated with LT for HCC (HALT-HCC), an oncological continuous risk score, to stratify waitlist dropout and post-LT outcomes.

METHODS

A competing risk model was developed and validated using the UNOS database (2012-2021) through multiple policy changes. The primary outcome was to assess the discrimination ability of waitlist dropouts and LT outcomes. The study focused on the HALT-HCC score, compared with other HCC risk scores.

RESULTS

Among 23,858 candidates, 14,646 (59.9%) underwent LT and 5196 (21.8%) dropped out of the waitlist. Higher HALT-HCC scores correlated with increased dropout incidence and lower predicted 5-year overall survival after LT. HALT-HCC demonstrated the highest area under the curve (AUC) values for predicting dropout at various intervals post-listing (0.68 at 6 months, 0.66 at 1 year), with excellent calibration (R2 = 0.95 at 6 months, 0.88 at 1 year). Its accuracy remained stable across policy periods and locoregional therapy applications.

CONCLUSIONS

This study highlights the predictive capability of the continuous oncological risk score to forecast waitlist dropout and post-LT outcomes in patients with HCC, independent of policy changes. The study advocates integrating continuous scoring systems like HALT-HCC in liver allocation decisions, balancing urgency, organ utility, and survival benefit.

Hepatocellular Carcinoma: Old and Emerging Therapeutic Targets

Liver cancer, predominantly hepatocellular carcinoma (HCC), globally ranks sixth in incidence and third in cancer-related deaths. HCC risk factors include non-viral hepatitis, alcohol abuse, environmental exposures, and genetic factors. No specific genetic alterations are unequivocally linked to HCC tumorigenesis. Current standard therapies include surgical options, systemic chemotherapy, and kinase inhibitors, like sorafenib and regorafenib. Immunotherapy, targeting immune checkpoints, represents a promising avenue. FDA-approved checkpoint inhibitors, such as atezolizumab and pembrolizumab, show efficacy, and combination therapies enhance clinical responses. Despite this, the treatment of hepatocellular carcinoma (HCC) remains a challenge, as the complex tumor ecosystem and the immunosuppressive microenvironment associated with it hamper the efficacy of the available therapeutic approaches. This review explores current and advanced approaches to treat HCC, considering both known and new potential targets, especially derived from proteomic analysis, which is today considered as the most promising approach. Exploring novel strategies, this review discusses antibody drug conjugates (ADCs), chimeric antigen receptor T-cell therapy (CAR-T), and engineered antibodies. It then reports a systematic analysis of the main ligand/receptor pairs and molecular pathways reported to be overexpressed in tumor cells, highlighting their potential and limitations. Finally, it discusses TGFβ, one of the most promising targets of the HCC microenvironment.

Serial circulating tumor DNA profiling predicts tumor recurrence after liver transplantation for liver cancer

BACKGROUND

Minimal residual disease (MRD) is proposed to be responsible for tumor recurrence. The role of circulating tumor DNA (ctDNA) to detect MRD, monitor recurrence, and predict prognosis in liver cancer patients undergoing liver transplantation (LT) remains unrevealed.

METHODS

Serial blood samples were collected to profile ctDNA mutational changes. Baseline ctDNA mutational profiles were compared with those of matched tumor tissues. Correlations between ctDNA status and recurrence rate (RR) and recurrence-free survival (RFS) were analyzed, respectively. Dynamic change of ctDNA was monitored to predict tumor recurrence.

RESULTS

Baseline mutational profiles of ctDNA were highly concordant with those of tumor tissues (median, 89.85%; range 46.2-100%) in the 74 patients. Before LT, positive ctDNA status was associated with higher RR (31.7% vs 11.5%; p = 0.001) and shorter RFS than negative ctDNA status (17.8 vs 19.4 months; p = 0.019). After LT, the percentage of ctDNA positivity decreased (17.6% vs 47.0%; p < 0.001) and patients with positive ctDNA status had higher RR (46.2% vs 21.3%; p < 0.001) and shorter RFS (17.2 vs 19.2 months; p = 0.010). Serial ctDNA profiling demonstrated patients with decreased or constant negative ctDNA status had lower RR (33.3% vs 50.0%; p = 0.015) and favorable RFS (18.2 vs 15.0 months, p = 0.003) than those with increased or constant positive ctDNA status. Serial ctDNA profiling predicted recurrence months ahead of imaging evidence and serum tumor biomarkers.

CONCLUSIONS

ctDNA could effectively detect MRD and predict tumor recurrence in liver cancer patients undergone LT.

Liver transplantation for elderly patients with early-stage hepatocellular carcinoma

BACKGROUND

Although liver resection is a viable option for patients with early-stage hepatocellular carcinoma (HCC), liver transplantation is the optimal treatment. The aim of this study was to identify characteristics of liver transplantation for elderly patients, and to assess the therapeutic benefit derived from liver transplantation over liver resection.

METHODS

This was a population-based study of patients undergoing liver transplantation for HCC in the USA between 2004 and 2018. Data were retrieved from the National Cancer Database. Elderly patients were defined as individuals aged 70 years and over. Propensity score overlap weighting was used to control for heterogeneity between the liver resection and liver transplantation cohorts.

RESULTS

Among 4909 liver transplant recipients, 215 patients (4.1 per cent) were classified as elderly. Among 5922 patients who underwent liver resection, 1907 (32.2 per cent) were elderly. Elderly patients who underwent liver transplantation did not have a higher hazard of dying during the first 5 years after transplantation than non-elderly recipients. After propensity score weighting, liver transplantation was associated with a lower risk of death than liver resection. Other factors associated with overall survival included diagnosis during 2016-2018, non-white/non-African American race, and α-fetoprotein level over 20 ng/dl.

CONCLUSION

Elderly patients with HCC should not be excluded from liver transplantation based on age only. Transplantation leads to favourable survival compared with liver resection.

Prolonged response to Tyrosine Kinase Inhibitors followed by Immunotherapy in metastatic hepatocellular carcinoma: A rare case report

The overall prognosis of hepatocellular carcinoma (HCC) is dismal and 5-year survival rate is 14.8%. We report a case of HCC coinfected with hepatitis C virus (HCV) and tumor thrombosis in the portal vein that was initially started on sorafenib followed by lenvatinib and nivolumab. On radiological imaging, there was a good partial response (PR) after starting nivolumab. A female 56 years of age presented with HCC coinfection with HCV, tumor thrombosis growing to the right portal vein. She received 6 months of sorafenib starting from April 2019 and was then switched to lenvatinib due to progressive disease. She continued lenvatinib for 11 months following which she developed new metastatic lesions where she was started on nivolumab. After 4 months of nivolumab, her alpha-fetoprotein decreased and there was a radiological PR. She is currently on nivolumab, with a total duration of response of 24 months on sorafenib followed by lenvatinib and lastly on nivolumab. Hence, tyrosine kinase inhibitors and immunotherapy can be effective lines treatment for advanced HCC and can give durable response duration, and probable radiological PR can be achieved with Nivolumab.

Predictors of early and late hepatocellular carcinoma recurrence

Hepatocellular carcinoma (HCC) is the most frequent liver neoplasm, and its incidence rates are constantly increasing. Despite the availability of potentially curative treatments (liver transplantation, surgical resection, thermal ablation), long-term outcomes are affected by a high recurrence rate (up to 70% of cases 5 years after treatment). HCC recurrence within 2 years of treatment is defined as “early” and is generally caused by the occult intrahepatic spread of the primary neoplasm and related to the tumor burden. A recurrence that occurs after 2 years of treatment is defined as “late” and is related to de novo HCC, independent of the primary neoplasm. Early HCC recurrence has a significantly poorer prognosis and outcome than late recurrence. Different pathogenesis corresponds to different predictors of the risk of early or late recurrence. An adequate knowledge of predictive factors and recurrence risk stratification guides the therapeutic strategy and post-treatment surveillance. Patients at high risk of HCC recurrence should be referred to treatments with the lowest recurrence rate and when standardized to combined or adjuvant therapy regimens. This review aimed to expose the recurrence predictors and examine the differences between predictors of early and late recurrence.

Elevated expression of RAB3B plays important roles in chemoresistance and metastatic potential of hepatoma cells

Background

Cancer stem cells (CSCs) are thought to play important roles in carcinogenesis, recurrence, metastasis, and therapy-resistance. We have successfully induced cancer stem-like sphere cells (CSLCs) which possess enhanced chemoresistance and metastatic potential. To enable the development of targeted therapy against CSLCs, we identified a gene responsible for this phenotype in CSLC.

Methods

Human hepatoma cell line SK-HEP-1 was used for CSLC induction with a unique sphere inducing medium, and HuH-7 cells were used as non-sphere forming cells in the same condition. RNA-sequencing was performed followed by validation with quantitative RT-PCR and western blotting. Knockdown experiments were done by using CRISPR-Cas9 genome-editing, and the rescue experiments were performed using the expressing plasmid vector. Chemoresistance and liver metastasis of the cells, was studied following the splenic injection of cells to severely immune deficient mice and evaluated using the MTS assay. Quantification of exosomes in the medium was done using ELISA.

Results

RAB3B was identified as an up-regulated gene in both CSLCs and prognostically poor hepatocellular carcinoma (HCC) by RNA-sequencing. RAB3B-KD cells showed altered CSLC phenotypes such as sphere formation, chemoresistance, and metastatic potentials, and those were rescued by RAB3B complementation. Increased exosome secretion was observed in CSLCs, and it was not observed in the RAB3B-KD cells. In addition, the RAB3B expression correlated with the expression of ABCG2, APOE, LEPR, LXN, and TSPAN13.

Conclusion

The up regulation of RAB3B may play an important role in the chemoresistance and metastatic potential of CSLCs.

Plasma MicroRNA Panel Predicts Early Tumor Recurrence in Patients with Hepatocellular Carcinoma after Liver Transplantation

Background: This study aimed to evaluate the role of plasma microRNA panel (miR-122, miR-192, miR-21, miR-223, miR-26a, miR-27a and miR-801) for prediction and surveillance of early tumor recurrence in hepatocellular carcinoma (HCC) patients who had undergone liver transplantation (LT). Methods: The expression of plasma microRNA panel was assayed in 193 HCC patients (training cohort, n =151; validation cohort, n = 42). Sensitivity and specificity for detecting post-transplant HCC recurrence, and the relationship of microRNA panel expression with clinical characteristics were analyzed accordingly. The prognostic value of microRNA panel was compared with that of AFP (alpha-fetoprotein) and DCP (Des-gamma-carboxyprothrombin). Cox regression analyses were used to evaluate independent prognostic factors. Results: In the training cohort, the rate of positive plasma microRNA panel status at 7-14 days after LT (late phase; 44.2%) decreased than that before (76.2%, P < 0.001) and 1-6 days after LT (early phase; 78.5%, P < 0.001). At late phase, positive microRNA panel status correlated with higher early tumor recurrence rate (one year after LT) than negative status (45.9% vs 10.7%; P < 0.001). Patients with persistent positive microRNA panel status both before and after LT had the highest early tumor recurrence rate in this cohort (54.9%, P < 0.001). The results were consistent in the validation cohort. Cox regression analysis found that positive plasma microRNA panel status at late phase was the only independent risk factor for early recurrence (HR: 4.903, 95% CI = 2.195 - 10.951; P < 0.001). Dynamic monitoring demonstrated plasma microRNA panel status changed from negative to positive earlier than AFP and DCP upon recurrence, and the median time between positivity of plasma microRNA and imaging evidence of recurrence was 2.4 (0.5-10.0) months. Conclusions: Plasma microRNA panel could be a noninvasive biomarker for prediction and surveillance of early tumor recurrence in HCC patients who have undergone LT.

Portal Vein Tumor Thrombosis and Hepatocellular Carcinoma - The Changing Tides

Portal vein involvement is considered one of the most fearful complications of hepatocellular carcinoma (HCC). Portal vein tumor thrombosis (PVTT) is associated with aggressive tumor biology (high grade), high tumor burden (number and size of lesions), high levels of serum markers (AFP), poor liver function (deranged LFT), and poor performance status of patients. The Barcelona Clinic Liver Cancer staging system places HCC patients with PVTT in advanced stage (BCLC Stage-C). This group contains a fairly heterogeneous patient population, previously considered candidates for palliative systemic therapy with sorafenib. However, this provided modest overall survival (OS) benefit. The results of a recent Phase III (IMbrave150) trial favor the combination of atezolizumab and bevacizumab over sorafenib as a standard of care in advanced unresectable HCC. While only lenvatinib proved to be non-inferior against sorafenib in a phase III (REFLECT trial), regorafenib (RESORCE trial), ramucirumab (REACH-2), and cabozantinib (CELESTIAL) have been approved second-line therapy in phase III clinical trials. Recently, the data on the prospect of other modalities in the management of HCC with PVTT is mounting with favorable results. Targeting multiple pathways in the HCC cascade using a combination of drugs and other modalities such as RT, TACE, TARE, and HAIC appear effective for systemic and loco-regional control. The quest for the ideal combination therapy and the sequence set is still widely unanswered and prospective trials are lacking. With the armament of available therapeutic options and the advances and refinements in the delivery system, down-staging patients to make them eligible for curative resection has been reported. In a rapidly evolving treatment landscape, performing surgery when appropriate, in the form of LR and even LT to achieve cure does not seem farfetched. Likewise, adjuvant therapy and prompt management of the recurrences holds the key to prolong OS and DFS. This review discusses the management options of HCC patients with PVTT.

A Meta-Analysis on the Rate of Hepatocellular Carcinoma Recurrence after Liver Transplant and Associations to Etiology, Alpha-Fetoprotein, Income and Ethnicity

Hepatocellular carcinoma (HCC) recurrence after liver transplant is associated with a poor prognosis and significantly increases morbidity and mortality among liver transplant patients. Therefore, this meta-analysis aims to evaluate the overall prevalence of HCC recurrence following liver transplant. Medline and Embase databases were searched, and a meta-analysis of proportions was conducted. Observational studies reporting the prevalence of recurrent hepatocellular carcinoma (HCC) after liver transplant were included, with the analysis being stratified by adherence to Milan criteria, ethnicity, socio-economic status, alpha fetoprotein (AFP) levels, living donor vs. deceased donor, and the underlying aetiology of the liver disease. A meta-regression on the date of the study completion was also performed. Of a total 40,495 patients, 3888 developed an HCC recurrence. The overall prevalence of recurrent HCC was 13% (CI: 0.12-0.15). Patients beyond the Milan criteria (MC) were more likely to recur than patients within MC. Asian populations had the greatest prevalence of HCC recurrence (19%; CI: 0.15-0.24) when compared to Western (12%; CI: 0.11-0.13) and Latin American populations (11%; CI: 0.09-0.14). The prevalence of recurrent HCC was the highest in patients infected with hepatitis B virus (HBV) (18%; CI: 0.11-0.27) compared to other aetiologies. A higher AFP also resulted in an increased recurrence. This highlights interesting differences based on ethnicity, income, and aetiology, and further studies are needed to determine the reasons for the disparity.