Clinical heterogeneity of pediatric hepatocellular carcinoma

LncRNA SATB2-AS1 overexpression represses the development of hepatocellular carcinoma through regulating the miR-3678-3p/GRIM-19 axis

Hepatocellular carcinoma (HCC) is a malignancy worldwide with one of the worst prognoses. Emerging studies have revealed that long noncoding RNAs (lncRNAs) contribute to HCC progression. This research probes the expression and regulatory effect of lncRNA SATB2-AS1 on HCC development. Reverse transcription-polymerase chain reaction (RT-PCR) was applied to measure the SATB2-AS1 profile in HCC tissues and adjacent non-tumor tissues. The impact of SATB2-AS1, miR-3678-3p, or GRIM-19 on HCC cell proliferation, growth, migration, invasion, and apoptosis was determined by gain- and loss-of-function experiments. The results revealed that SATB2-AS1 was downregulated in HCC tissues, and its lower levels were related to higher tumor staging and poorer prognosis of HCC patients. SATB2-AS1 overexpression repressed HCC cell proliferation, induced G1 arrest, and apoptosis, and inhibited migration, invasion, and epithelial-mesenchymal transition (EMT). Mechanistically, SATB2-AS1 inactivated STAT3/HIF-1α and strengthened GRIM-19 expression. After knocking down GRIM-19 with small interfering RNA (siRNA), the malignant phenotypes of HCC cells were enhanced. Further bioinformatics analysis showed that miR-3678-3p was targeted by SATB2-AS1. The dual-luciferase reporter assay, RNA immunoprecipitation (RIP) experiment, and Fluorescence in situ Hybridization (FISH) test confirmed that SATB2-AS1 sponged miR-3678-3p and the latter targeted GRIM-19. The rescue experiments showed that miR-3678-3p aggravated the malignant behaviors of HCC cells, whereas SATB2-AS1 overexpression reversed miR-3678-3p-mediated effects. Inhibition STAT3 promoted SATB2-AS1 and GRIM-19 expression, and reduced miR-3678-3p level. Activation STAT3 exerted opposite effects. Overall, this study confirmed that SATB2-AS1 is a potential prognostic biomarker for HCC and regulates HCC devolvement by regulating the miR-3678-3p/GRIM-19/STAT3/HIF-1α pathway.

Pathologic and Immunophenotypic Characterization of Syncytial Giant Cell Variant of Pediatric Hepatocellular Carcinoma. A Distinct Subtype

INTRODUCTION

Hepatocellular carcinoma (HCC) in pediatrics has a uniformly poor prognosis. Complete surgical resection or liver transplantation remain the only curative options. In contrast to adult HCC, literature on pediatric HCC is sparse and a majority of the distinct subtypes are undefined with regards to their histology, immunohistochemistry and prognosis.

CASE REPORT

Two infants, one with biliary atresia and another with transaldolase deficiency, underwent living donor liver transplants. Explant-liver histopathology revealed tumor with diffuse neoplastic syncytial giant cell pattern. Immunophenotypic characterization highlighted expression of epithelial cell adhesion molecule, alpha fetoprotein and metallothionein.

CONCLUSION

HCC with syncytial giant cells variant can occur in infants with underlying liver disease, specifically in our experience, with biliary atresia and another with transaldolase deficiency.

Treatment and Prognosis of Fibrolamellar Hepatocellular Carcinoma: a Systematic Review of the Recent Literature and Meta-analysis

BACKGROUND

Fibrolamellar hepatocellular carcinoma (FL-HCC) is a rare disease and current efforts are focused on the prognosis and on the development of efficient and specific treatments. This study aimed to review the latest evidence regarding FL-HCC treatment and prognosis.

METHODS

A systematic review of the literature over the past 10 years regarding FL-HCC, and meta-analysis of 1-, 3-, and 5-year overall survival (OS) comparing FL-HCC and conventional HCC were performed.

RESULTS

Overall, 1567 articles were screened, of them 21 were selected for the systematic review, and 6 for meta-analysis. Twenty-one studies included a total of 2168 patients with FL-HCC, with a median age ranging from 11 to 56 years. The majority of patients underwent surgical resection or liver transplantation. After a median follow-up ranging from 24 to 58 months, 1-year OS was 67-100% and 5-year OS was 28-65%. A total of 743 patients with FL-HCC and 163,472 with conventional HCC were included in the meta-analysis. There was a significantly improved 1-, 3-, and 5-years OS in the FL-HCC group compared to the conventional HCC group, although high heterogeneity was found. When excluding population-based studies, and including 96 FL-HCC and 221 conventional HCC patients, the heterogeneity was low, and the meta-analysis showed a significantly longer 1-year OS in patients with FL-HCC than conventional HCC; however, there were no differences at 3- and 5-years OS.

CONCLUSIONS

Surgical resection for FL-HCC is currently the only curative treatment available. FL-HCC is plagued by high-recurrence rates and poor long-term outcomes which may be related to the absence of specific treatment for advanced and recurrent disease.

Incidence and trends of hepatic cancer among children and adolescents in the United States from 2000 to 2017: Evidence from the Surveillance, Epidemiology, and End Results registry data

OBJECTIVE

Primary liver tumors are rare pediatric malignancies. Knowledge of the epidemiology of pediatric liver tumors is limited. This study aims to present the national incidence trends of pediatric liver tumors over 18 years, according to sociodemographic and histological subtype variation.

METHODS

The Surveillance, Epidemiology, and End Results registry was queried from 2000 to 2017 for 1,099 patients between ages 0 and 19 with liver tumors. Age-standardized incidence rates by age, sex, and race/ethnicity were examined among histological subtypes. Annual percentage change (APC) was calculated via joinpoint regression for various sociodemographic and histotype subgroups.

RESULTS

An increase of age-adjusted incidence rate of pediatric hepatic cancers was observed between 2000 and 2017 (APC, 1.7% [95% confidence interval or CI: 0.6%-2.8%], p-value = 0.006), which may likely attribute to the increasing incidence of hepatoblastoma and mesenchymal tumors (APC, 2.5% [95% CI: 1.1%-3.8%], p-value = 0.001). The incidence trend of hepatocellular carcinoma remained stable in the study period. The non-Hispanic Asian/Pacific Islander children and adolescents had a higher risk of hepatic tumors (incidence rate ratio or IRR, 1.42 [95% CI: 1.16-1.72], p-value = 0.0007) when compared with the non-Hispanic white subgroup, while a non-Hispanic black child was associated with a lower incidence rate (IRR, 0.64 [95% CI: 0.50-0.80], p-value < 0.0001). Significantly lower hepatic tumor incidence occurred in females than males, with an incidence rate ratio of 0.69 (95% CI: 0.61-0.78; p-value < 0.0001). Hepatic tumor incidence was also significantly lower in those aged 1-4 years (IRR, 0.47 [95% CI: 0.40-0.54]; p-value < 0.001) and 5-19 years (IRR, 0.09 [95% CI: 0.08-0.10]; p-value < 0.001) when compared with the youngest age group aged less than 1 year. These significant differences were also detected for the subgroup of hepatoblastoma and mesenchymal liver tumors but less among hepatocellular carcinomas (all p-values less than 0.0001).

CONCLUSION

Continued increasing incidence of pediatric hepatoblastoma and mesenchymal liver tumors was discovered and warranted further investigation. Additional findings include a lower incidence of hepatic cancer among non-Hispanic black individuals and higher incidence of hepatic cancer in non-Hispanic Asian/Pacific Islander, male, and aged 1-4-year children and adolescents.

State of the art and perspectives in pediatric hepatocellular carcinoma

Hepatoblastoma (HB) and pediatric hepatocellular carcinoma (HCC) are rare primary malignant liver cancers in children and young adults. HB is the most common and accounts for about 70 % cases; it is usually diagnosed during the first 3 years of life. Instead, pediatric HCC is uncommon, and it is associated with a poor prognosis. Overall, the prognosis of pediatric HCC is dismal with 5-year event-free survival of <30 % as compared to >80 % for HB. Surgery approaches, either resection or transplant, remain the best chance for the cure of pediatric HCC. However, chemotherapy can be helpful as an adjuvant or neoadjuvant treatment. International groups have done trials in pediatric HCC with a chemotherapy regimen, based on cisplatin and doxorubicin (PLADO) as for HB, but the efficacy is limited. Sorafenib, a multi-kinase inhibitor, following positive results in adults and in a pilot study in children, is now tested in conjunction with chemotherapy in the PHITT phase III clinical trial. Some studies have been exploring the genetic profiles of patients to find biological hallmarks that determine the aggressiveness of pediatric HCC. Pathways involved in growth and differentiation are dysregulated and as demonstrated in HB and adult HCC, an important role of the Wnt/CTNNB1 pathway in the pathogenesis of pediatric HCC is also emerging. An extended molecular analysis of tumor samples could give information about pathways as possible targets of biological and immunotherapeutic agents bringing new pharmacological options for the treatment of pediatric HCC.

Rare Inherited Cholestatic Disorders and Molecular Links to Hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is the most common primary liver cancer affecting adults and the second most common primary liver cancer affecting children. Recent years have seen a significant increase in our understanding of the molecular changes associated with HCC. However, HCC is a complex disease, and its molecular pathogenesis, which likely varies by aetiology, remains to be fully elucidated. Interestingly, some inherited cholestatic disorders that manifest in childhood are associated with early HCC development. This review will thus explore how three genes that are associated with liver disease in childhood (ABCB11, TJP2 and VPS33B) might play a role in the initiation and progression of HCC. Specifically, chronic bile-induced damage (caused by ABCB11 changes), disruption of intercellular junction formation (caused by TJP2 changes) and loss of normal apical–basal cell polarity (caused by VPS33B changes) will be discussed as possible mechanisms for HCC development.

Integrated analysis using ToppMiR uncovers altered miRNA- mRNA regulatory networks in pediatric hepatocellular carcinoma-A pilot study

BACKGROUND

Pediatric hepatocellular carcinoma (HCC) is a group of liver cancers whose mechanisms behind their pathogenesis and progression are poorly understood.

AIM

We aimed to identify alterations in the expression of miRNAs and their putative target mRNAs in not only tumor tissues of patients with pediatric HCC but also in corresponding non-tumorous background livers by using liver tissues without underlying liver disease as a control.

METHODS AND RESULTS

We performed a small-scale miRNA and mRNA profiling of pediatric HCC (consisting of fibrolamellar carcinoma [FLC] and non-FLC HCC) and paired liver tissues to identify miRNAs whose expression levels differed significantly from control livers without underlying liver disease. ToppMiR was used to prioritize both miRNAs and their putative target mRNAs in a gene-annotation network, and the mRNA profile was used to refine the prioritization. Our analysis generated prioritized lists of miRNAs and mRNAs from the following three sets of analyses: (a) pediatric HCC versus control; (b) FLC versus control; and (c) corresponding non-tumorous background liver tissues from the same patients with pediatric HCC versus control. No liver disease liver tissues were used as the control group for all analyses. Many miRNAs whose expressions were deregulated in pediatric HCC were consistent with their roles in adult HCC and/or other non-hepatic cancers. Our gene ontology analysis of target mRNAs revealed enrichment of biological processes related to the sustenance and propagation of cancer and significant downregulation of metabolic processes.

CONCLUSION

Our pilot study indicates that alterations in miRNA-mRNA networks were detected in not only tumor tissues but also corresponding non-tumorous liver tissues from patients with pediatric HCC, suggesting multi-faceted roles of miRNAs in disease progression. Our results may lead to novel hypotheses for future large-scale studies.

Imaging Features of Hepatocellular Carcinoma in Children With and Without Underlying Risk Factors

Background: Pediatric hepatocellular carcinoma (HCC) is an aggressive malignancy for which imaging findings remain poorly described. In comparison with adult HCC, pediatric HCC more commonly occurs without underlying risk factors, and standardized surveillance guidelines for those with predispositions are lacking. Objective: To evaluate imaging findings of non-fibrolamellar pediatric HCC and to identify associations between these imaging findings and presence of predisposing factors. Methods: This retrospective study included children (≤18 years) with histologically confirmed non-fibrolamellar HCC who underwent multiphase CT or MRI at one of four academic children's hospitals between July 2009 and April 2019. Surveillance regimens in children with predispositions were at the discretion of treating physicians. Clinical characteristics were recorded. Scan indications were classified as surveillance versus clinical signs and symptoms. Images from all sites were submitted to a cloud-based server. Two radiologists independently assessed imaging features of HCC, including tumor size, tumor in vein, Pre-Treatment Extent of Tumor (PRETEXT) stage, and LI-RADS major features of adult HCC. Imaging findings were compared between patients with and without predispositions. Results: The study included 39 patients: 17 with predispositions (mean age, 11±5 years; 9 boys, 8 girls) and 22 without predispositions (mean age, 11±5 years; 12 boys, 10 girls). Scan indication was surveillance in 14/17 patients with predispositions versus 0/22 patients without predispositions (P<.001). Patients with, versus without, predispositions had smaller tumor size [reader 1: 6.0 vs 11.9 cm (p=.003); reader 2: 6.0 vs 12.9 cm (p<.001)] and less frequent tumor in vein [reader 1: 0% vs 41% (p=.002); reader 2: 0% vs 36% (p=.006)]. PRETEXT stage of IV was observed in 18% (both readers) of patients with predispositions versus 50-55% of patients without predispositions. No LI-RADS major feature of adult HCC showed a significant difference in frequency between patients with and without predispositions for either reader (all P>.05). Conclusion: Among children with HCC, those with predispositions were diagnosed with smaller and lower-stage tumors having less frequent tumor in vein, likely due to surveillance imaging. Clinical Impact: The study supports the role of routine surveillance imaging in children with HCC predispositions to facilitate earlier detection. Standardization of surveillance guidelines remains needed.

The utility of hierarchical genetic testing in paediatric liver disease

BACKGROUND & AIMS

Genetic factors underlie a substantial proportion of paediatric liver diseases. Hereditary liver diseases have considerable genetic heterogeneity and variable clinical manifestations, which bring great challenges to clinical and molecular diagnoses. In this study, we investigated a group of paediatric patients with varying degrees of liver dysfunction using a hierarchical genetic testing strategy.

METHODS

We first applied a panel encompassing 166 known causal genes of liver disease. We then used exome sequencing (ES) in those patients whose cases remained undiagnosed to identify the genetic aetiology of their symptoms.

RESULTS

In total, we enrolled 131 unrelated paediatric patients with liver disease of Chinese Han ethnicity. We first applied targeted gene sequencing of 166 genes to all patients and yielded a diagnostic rate of 35.9% (47 of 131). Eighty-four patients who remained undiagnosed after target gene sequencing were subjected to ES. As a result, eight (8/84, 9.5%) of them obtained molecular diagnoses, including four patients suspected of abnormal bilirubin metabolism and four idiopathic cases. Non-typical genetic findings, including digenic inheritance and dual molecular diagnosis, were also identified. Through a comprehensive assessment of novel candidate variants of uncertain disease association, 11 patients of the remaining undiagnosed patients were able to obtain likely molecular diagnoses.

CONCLUSIONS

Our study presents evidence for the diagnostic utility of sequential genetic testing in a cohort of patients with paediatric liver disease. Our findings expand the understanding of the phenotypic and mutational spectrum underlying this heterogeneous group of diseases.

Liver Transplantation for Pediatric Hepatocellular Carcinoma: A Systematic Review

Liver transplantation (LT) is the only potentially curative option for children with unresectable hepatocellular carcinoma (HCC). We performed a systematic review of the MEDLINE, Scopus, Cochrane Library, and Web of Science databases (end-of-search date: 31 July 2020). Our outcomes were overall survival (OS) and disease-free survival (DFS). We evaluated the effect of clinically relevant variables on outcomes using the Kaplan-Meier method and log-rank test. Sixty-seven studies reporting on 245 children undergoing LT for HCC were included. DFS data were available for 150 patients and the 1-, 3-, and 5-year DFS rates were 92.3%, 89.1%, and 84.5%, respectively. Sixty of the two hundred and thirty-eight patients (25.2%) died over a mean follow up of 46.8 ± 47.4 months. OS data were available for 222 patients and the 1-, 3-, and 5-year OS rates were 87.9%, 78.8%, and 74.3%, respectively. Although no difference was observed between children transplanted within vs. beyond Milan criteria (p = 0.15), superior OS was observed in children transplanted within vs. beyond UCSF criteria (p = 0.02). LT can yield favorable outcomes for pediatric HCC beyond Milan but not beyond UCSF criteria. Further research is required to determine appropriate LT selection criteria for pediatric HCC.

Rare variants of primary liver cancer: Fibrolamellar, combined, and sarcomatoid hepatocellular carcinomas

Hepatocellular carcinoma (HCC) constitutes 80% of all primary liver cancers. Based on key developments in the understanding of its carcinogenesis and the advancement of treatment options, detailed algorithms and practice guidelines have been published to guide the clinical management of HCC. Furthermore, several subclasses of HCC have been described based on molecular profiles and linked to pathological characteristics, clinical features, and disease aggressiveness. Most recently, the combination of the checkpoint inhibitor atezolizumab plus bevacizumab has significantly increased treatment response in the first line systemic treatment of HCC. Unfortunately, rare HCC variants, in particular fibrolamellar liver cancer (FLC), combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CCA), and sarcomatoid hepatocellular carcinoma (sHCC), were excluded from phase III studies. Therefore, data for decision-making and treatment allocation for these distinct entities, representing 1-5% of all primary liver cancers, is scarce. Moreover, most of the knowledge available for these rare HCC variants is based on registry data and retrospective studies. In this position paper, we briefly summarize the current clinical knowledge regarding FLC, cHCC-CCA, and sHCC. Based on our summary, we propose future clinical research activities within the framework of the European Reference Network on Hepatological Diseases (ERN RARE-LIVER).

Pediatric Primary Hepatic Tumors: Diagnostic Considerations

The liver is the third most common site of abdominal tumors in children. This review article aims to summarize current evidence surrounding identification and diagnosis of primary hepatic tumors in the pediatric population based upon clinical presentation, epidemiology, and risk factors as well as classical imaging, histopathological, and molecular diagnostic findings. Readers will be able to recognize the features and distinguish between benign and malignant hepatic tumors within different age groups.

Alagille syndrome and risk for hepatocellular carcinoma: Need for increased surveillance in adults with mild liver phenotypes

Alagille syndrome (ALGS) is a multisystem autosomal dominant developmental disorder caused predominantly by pathogenic variants in JAGGED1 (JAG1), and also by pathogenic variants in NOTCH2 in a much smaller number of individuals. Clinical presentation is highly variable and includes liver, heart, eye, skeleton, and facial abnormalities, with a subset of individuals also presenting with kidney, vascular, and central nervous system phenotypes. Hepatocellular carcinoma (HCC) is a rare complication of ALGS, though little is known about its incidence or etiology among affected individuals. Previous reports have identified HCC occurrence in both pediatric and adult cases of ALGS. We present a case report of HCC in a 58‐year‐old woman with a pathogenic JAG1 variant and no overt hepatic features of ALGS. Through a comprehensive literature review, we compile all reported pediatric and adult cases, and further highlight one previously reported case of HCC onset in an adult ALGS patient without any hepatic disease features, similar to our own described patient. Our case report and literature review suggest that ALGS‐causing variants could confer risk for developing HCC regardless of phenotypic severity and highlight a need for a cancer screening protocol that would enable early detection and treatment in this at‐risk population.