Malignant tumors of the liver in children

Surgical management of liver tumors

Two percent of pediatric malignancies arise primarily in the liver; roughly 60% of these cancers are hepatoblastoma (HB). Despite the rarity of these cases, international collaborative efforts have led to the consistent histological classification and staging systems, which facilitate ongoing clinical trials. Other primary liver malignancies seen in children include hepatocellular carcinoma (HCC) with or without underlying liver disease, fibrolamellar carcinoma (FLC), undifferentiated embryonal sarcoma of the liver (UESL), and hepatocellular neoplasm not otherwise specified (HCN-NOS). This review describes principles of surgical management of malignant pediatric primary liver tumors, within the context of comprehensive multidisciplinary care.

Early Surgical Outcome of Hepatoblastoma in Children Receiving Chemotherapy After Hepatic Resection

OBJECTIVE

 The aim of this study was to evaluate surgical outcomes in children with hepatoblastoma who underwent hepatic resection after receiving neoadjuvant chemotherapy.

METHODOLOGY

A prospective observational longitudinal study was conducted from February 2019 to July 2020 in the Department of Pediatric Surgery at Bangabandhu Sheikh Mujib Medical University, Bangladesh. A total of 13 children diagnosed with hepatoblastoma and classified as PRETEXT (Pre-Treatment Extent of Disease) stages I to III were included. Detailed medical histories were recorded, and diagnoses were confirmed through histopathological analysis. Preoperative evaluations included liver function tests (LFTs), serum alpha-fetoprotein (AFP) levels, and imaging for tumor staging and liver volume. Postoperative assessments were conducted at one, three, and six months to monitor changes in serum AFP levels, LFTs, liver volume, and hepatic echotexture. The type of hepatic resection performed and any complications encountered were also documented.

RESULTS

Among the 13 patients, the majority were male, with a male-to-female ratio of 12:1. The average age at diagnosis was 4.44 years, with most patients under three years old. Pathological analysis revealed epithelial tumors in 38.45% of cases, fetal-type tumors in 46.15%, and mixed tumors in 15.4%. PRETEXT stage III was the most common (53.85%), and 61.54% of patients underwent major hepatic resections. Postoperative serum AFP levels showed a significant decline, reflecting successful tumor resection and improvements in LFTs. Improvements in LFTs, including key enzymes like ALT and AST, were observed. A marked increase in hepatic regeneration was observed within six months, with no local recurrences recorded.

CONCLUSIONS

This study highlights the effectiveness of combining hepatic resection with neoadjuvant chemotherapy in treating pediatric hepatoblastoma. A significant decline in serum AFP levels after surgery reflects the success of tumor removal, while improvements in LFTs underscore the recovery of hepatic health. Furthermore, the observed increase in hepatic regeneration within six months demonstrates the liver's remarkable ability to recover and sustain long-term function. These findings emphasize the importance of early diagnosis, precise surgical techniques, and individualized treatment planning in improving outcomes for pediatric hepatoblastoma.

Reappraisal of liver resection as an alternative to transplantation in locally advanced hepatoblastoma: A systematic review and analysis of pooled individual patient data

BACKGROUND

There is ongoing debate regarding liver transplantation (LT) versus liver resection (LR) for locally advanced hepatoblastoma. However, comparative studies are lacking. Consequently, a significant evidence gap persists, hindering the establishment of consensus guidelines. This study aimed to compare LT and LR for locally advanced hepatoblastoma, using predefined inclusion criteria to ensure comparable intervention groups.

METHODS

According to current Children's Oncology Group (COG) and SIOPEL (European Childhood Liver Tumour Study Group) recommendations, hepatoblastoma that requires LT evaluation was defined as either PRETEXT (PRE-Treatment EXTent of tumor) IV F+, POST-TEXT (POST-Treatment EXTent of tumor) IV, POST-TEXT P+, and/or POST-TEXT V+. A systematic literature search (Medline/Web-of-Science/Embase) was performed. Only patients who met the aforementioned criteria were included. Patient data were extracted individually and pooled.

RESULTS

A total of 189 patients with locally advanced hepatoblastoma from 55 studies met the specified criteria, with 111 undergoing LT and 78 LR. There were no significant differences between the two groups in age, alpha-fetoprotein (AFP), and PRETEXT stages. Local recurrence was more common after LR (14% vs. 3% in LT, p = .008), while distant recurrence was more often observed after LT (16% vs. 5% in LR, p = .035). Overall survival (OS) and event-free survival (EFS) did not differ significantly between LT and LR (5-year OS: LT = 75.3% [95% confidence interval: 66.5-85.2], LR = 87.6% [80.4-95.6], p = .140; 5-year EFS: LT = 68.5% [59.3-79.1], LR = 71.1% [60.7-83.3], p = .700).

CONCLUSION

Real-life data revealed that a considerable number of patients with locally advanced hepatoblastoma underwent LR. This analysis suggests that outcomes are similar and favorable for both approaches. LR can therefore be considered an effective alternative to LT in selected cases even in locally advanced hepatoblastoma.

Liver transplantation for pediatric liver malignancies

In the last few decades, collaboration between international pediatric oncology groups has resulted in significant improvement in survival after liver transplantation (LT) for pediatric liver tumors, and LT has become the accepted standard of care for unresectable pediatric liver tumors-either living donor liver transplantation or deceased donor liver transplantation. Hepatoblastoma and HCC are the common pediatric liver malignancies treated by LT, and LT is now the accepted treatment modality for unresectable nonmetastatic cases. The long-term survival rate is more than 80% in hepatoblastoma transplants. Furthermore, with the advent of living donor liver transplantation, the waitlist mortality, availability of a better graft quality with shorter ischemic times, and performance of LT with the appropriate timing between chemotherapy have all improved. Up to 80% of pediatric HCCs are unresectable, and studies have shown that LT for pediatric HCC has better outcomes than liver resection. Furthermore, LT has also shown better results than liver resection for cases of HCC not meeting Milan criteria. Given the rarity of pediatric liver malignancies and challenges in optimal management, a multidisciplinary treatment approach, research models building on what is already known, and consideration of newer treatment modalities are required for further improving the treatment of pediatric liver malignancies.

FOXM1 and CHD4 expression is associated with chemoresistance in hepatoblastoma

Hepatoblastoma (HB) is the most common malignant liver tumor in childhood. Although pre-operative cisplatin (CDDP)-based chemotherapy is often used in cases of HB, about 20％ of HB patients exhibit resistance to CDDP. Forkhead box protein M1 (FOXM1) and chromo-domain-helicase-DNA-binding protein 4 (CHD4) have been associated with CDDP resistance in various tumors. We here analyzed the immunohistochemical expression of FOXM1 and CHD4 in HB specimens of 33 patients (mean age: 20 months) post-chemotherapy. The differentiation of specimens was assessed using the digital pathology software QuPath®, and then the relation between the FOXM1 or CHD4 expression and the differentiation and various other clinicopathological parameters was investigated. The histological type was epithelial in 19 cases (57.6%) and mixed epithelial and mesenchymal in 14 cases (42.4%). Nine cases had only a fetal component, 1 case had only an embryonal component, 22 cases had both fetal and embryonal components, and 1 case had no viable tumor. Both the FOXM1 and CHD4 immunoexpressions were found significantly more frequently in the embryonal than fetal components (p<0.0001 and p<0.0001, respectively). Regarding chemotherapy efficacy, the alpha-fetoprotein (AFP) level after chemotherapy was correlated with both the imaging shrinkage rate (R=-0.52) and histological residual rate (the percentage of the viable tumors of HB after chemotherapy)(R=0.62). High FOXM1 score was correlated with a high-postoperative AFP value (p<0.01) and a low AFP attenuation rate (p<0.05), but the FOXM1 score was not correlated with the imaging shrinkage rate (p=0.4418) or histological residual rate (p=0.4418). High CHD4 score showed a nonsignificant trend toward correlation with high postoperative AFP value (p=0.0849) and was not significantly correlated with the other parameters. Collectively, our results showed that FOXM1 expression may be useful in evaluating the response to CDDP-based chemotherapeutic regimens. Accurate measurement of FOXM1 expression by our scoring system using QuPath® is important in cases with mixed HB components of various differentiation levels.

Single-cell multiomics reveals the interplay of clonal evolution and cellular plasticity in hepatoblastoma

Hepatoblastomas (HB) display heterogeneous cellular phenotypes that influence the clinical outcome, but the underlying mechanisms are poorly understood. Here, we use a single-cell multiomic strategy to unravel the molecular determinants of this plasticity. We identify a continuum of HB cell states between hepatocytic (scH), liver progenitor (scLP) and mesenchymal (scM) differentiation poles, with an intermediate scH/LP population bordering scLP and scH areas in spatial transcriptomics. Chromatin accessibility landscapes reveal the gene regulatory networks of each differentiation pole, and the sequence of transcription factor activations underlying cell state transitions. Single-cell mapping of somatic alterations reveals the clonal architecture of each tumor, showing that each genetic subclone displays its own range of cellular plasticity across differentiation states. The most scLP subclones, overexpressing stem cell and DNA repair genes, proliferate faster after neo-adjuvant chemotherapy. These results highlight how the interplay of clonal evolution and epigenetic plasticity shapes the potential of HB subclones to respond to chemotherapy.

EZH2 is a key component of hepatoblastoma tumor cell growth

BACKGROUND

Enhancer of zeste homolog 2 (EZH2) catalyzes the trimethylation of histone H3 at lysine 27 via the polycomb recessive complex 2 (PRC2) and plays a time-specific role in normal fetal liver development. EZH2 is overexpressed in hepatoblastoma (HB), an embryonal tumor. EZH2 can also promote tumorigenesis via a noncanonical, PRC2-independent mechanism via proto-oncogenic, direct protein interaction, including β-catenin. We hypothesize that the pathological activation of EZH2 contributes to HB propagation in a PRC2-independent manner.

METHODS AND RESULTS

We demonstrate that EZH2 promotes proliferation in HB tumor-derived cell lines through interaction with β-catenin. Although aberrant EZH2 expression occurs, we determine that both canonical and noncanonical EZH2 signaling occurs based on specific gene-expression patterns and interaction with SUZ12, a PRC2 component, and β-catenin. Silencing and inhibition of EZH2 reduce primary HB cell proliferation.

CONCLUSIONS

EZH2 overexpression promotes HB cell proliferation, with both canonical and noncanonical function detected. However, because EZH2 directly interacts with β-catenin in human tumors and EZH2 overexpression is not equal to SUZ12, it seems that a noncanonical mechanism is contributing to HB pathogenesis. Further mechanistic studies are necessary to elucidate potential pathogenic downstream mechanisms and translational potential of EZH2 inhibitors for the treatment of HB.

An update on diagnosis and treatment of hepatoblastoma

Hepatoblastoma (HB) remains the most common paediatric liver tumour and survival in children with hepatoblastoma has improved considerably since the advent of sequential surgical regimens of chemotherapy based on platinum-based chemotherapeutic agents in the 1980s. With the advent of modern diagnostic imaging and pathology techniques, new preoperative chemotherapy regimens and the maturation of surgical techniques, new diagnostic and treatment options for patients with hepatoblastoma have emerged and international collaborations are investigating the latest diagnostic approaches, chemotherapy drug combinations and surgical strategies. Diagnosis of hepatoblastoma relies on imaging studies (such as ultrasound, computed tomography, and magnetic resonance imaging), alpha-fetoprotein (AFP) levels, and histological confirmation through biopsy. The standard treatment approach involves a multimodal strategy with neoadjuvant chemotherapy followed by surgical resection. In cases where complete resection is not feasible or tumors exhibit invasive characteristics, liver transplantation is considered. The management of metastatic and recurrent hepatoblastoma poses significant challenges, and ongoing research focuses on developing targeted therapies and exploring the potential of immunotherapy. Further studies are necessary to gain a better understanding of the etiology of hepatoblastoma, develop prevention strategies, and personalize treatment approaches. We aim to review the current status of diagnosis and treatment of hepatoblastoma.

Parenchyma Sparing Anatomic Liver Resections (Bi- and Uni-Segmentectomies) for Liver Tumours in Children-A Single-Centre Experience

Purpose: To present a single-centre experience in bi- and uni-segmentectomies for primary liver tumours in children.

METHODS

This study included 23 patients that underwent (bi)segmentectomy. There were 15 malignant tumours (hepatoblastoma-13 patients), 7 benign tumours, and 1 calcifying nested stromal epithelial tumour.

RESULTS

The median tumour diameter was 52 mm (range 15-170 mm). Bisegmentectomy 2-3 was most frequently performed (seven patients), followed by bisegmentectomy 5-6 (four patients). The median operative time was 225 min (range 95-643 min). Intraoperative complications occurred in two patients-small bowel perforation in one and an injury of the small peripheral bile duct resulting in biloma in the other. The median resection margin in patients with hepatoblastoma was 3 mm (range 1-15 mm). Microscopically negative margin status was achieved in 12 out of 13 patients. There were two recurrences. After a median follow-up time of 38 months (range 12-144 months), all 13 patients with HB were alive with no evidence of disease. Two relapsed patients were alive with no evidence of disease.

CONCLUSIONS

From the available literature and data presented here, we propose that (bi)segmentectomy can become a viable surgical option in carefully selected paediatric patients and is sufficient to achieve a cure. Further studies evaluating the impact of parenchymal preservation surgery on surgical and oncological outcome should be conducted with a larger dataset.

Review on Pediatric Malignant Focal Liver Lesions with Imaging Evaluation: Part I

Malignant focal liver lesions (FLLs) are commonly reported in adults but rarely seen in the pediatric population. Due to the rarity, the understanding of these diseases is still very limited. In children, most malignant FLLs are congenital. It is very important to choose appropriate imaging examination concerning various factors. This paper will outline common pediatric malignant FLLs, including hepatoblastoma, hepatocellular carcinoma, and cholangiocarcinoma and discuss them against the background of the latest knowledge on comparable/similar tumors in adults. Medical imaging features are of vital importance for the non-invasive diagnosis and follow-up of treatment of FLLs in pediatric patients. The use of CEUS in pediatric patients for characterizing those FLLs that remain indeterminate on conventional B mode ultrasounds may be an effective option in the future and has great potential to be integrated into imaging algorithms without the risk of exposure to ionizing radiation.

Biology of childhood hepatoblastoma and the search for novel treatments

Our research laboratory has a longstanding interest in developmental disorders and embryonic tumors, and recent efforts have focused on the pathogenesis of pediatric liver tumors. This review focuses on hepatoblastoma (HB), the most common pediatric liver malignancy. Despite advances in treatment, patients with metastatic HB have a poor prognosis, and survivors often have permanent side effects attributable to chemotherapy. In an effort to improve survival and lessen long-term complications of HB, we have searched for novel molecular vulnerabilities using a combination of patient derived cell lines, metabolomics, and RNA sequencing of human samples at diagnosis and follow-up. These studies have shed light on pathogenesis and identified putative targets for future therapies in children with advanced HB.

Ferroptosis regulator NOS2 is closely associated with the prognosis and cell malignant behaviors of hepatoblastoma: a bioinformatic and in vitro study

Background

Hepatoblastoma (HB) is the most common liver tumor in children with easy metastasis. The emergence of ferroptosis as a novel form of cell death has gained increased attention in various human cancers. However, the roles of ferroptosis-related (FR) genes in HB remain elusive.

Methods

The GSE133039, GSE131329, and GSE81928 datasets were utilized for screening core FR genes in HB. Through Lasso regression analysis and using the support vector machine recursive feature elimination (SVM-RFE) algorithm, three candidate FR genes were obtained for characterizing HB. Their expression patterns and their clinical associations were explored through the 'Limma' R package, and their diagnostic potential was evaluated using ROC curves. Nitric oxide synthase 2 (NOS2) emerged as a candidate for further analyses. The CIBERSORT algorithm and GSEA dataset were used to respectively investigate the immune and metabolism effects of NOS2; the former was validated through immunofluorescence. The GSDC database was employed to analyze the correlation between NOS2 expression and the therapeutic efficacy of multiple drugs. PCR, Western blotting, colony formation assays, and Transwell experiments, were used to determine biological functions of NOS2 in HB cells. Potential upstream transcription factors of NOS2 were predicted through the TRRUST, hTFtarget, GeneCards, and JASPAR databases.

Results

NQO1, SLC1A4, and NOS2 were identified as potential genes in HB and found to be significantly upregulated in tumor samples. Nevertheless, only NOS2 was closely associated with HB clinicopathological characteristics; high NOS2 expression indicated poor prognosis, metastatic tendency, and late clinical stage. Immune analyses indicated that high NOS2 expression was concomitant with decreased infiltration levels of CD8+ T cells but increased infiltration levels of macrophages. GSEA revealed that NOS2 failed to affect the enrichments of glycolysis, fatty acid metabolism, and cholesterol biosynthesis in HB. Moreover, NOS2 was positively correlated with the IC50 values of trametinib, lapatinib, and cisplatin. NOS2 overexpression promoted the proliferation, migration and invasion of HepG2 and HuH-6 cells. JUND was identified as a potential transcriptional regulator of NOS2 by binding to its promoter (5'-TTCTGACTCTTTT-3').

Conclusion

NOS2 plays a significant role in HB clinical assessments and holds promise as a novel therapeutic target.

Vincristine/irinotecan/temsirolimus upfront window treatment of high-risk hepatoblastoma: A report from the Children's Oncology Group AHEP0731 Study Committee

BACKGROUND

Survival for children with metastatic hepatoblastoma (HB) remains suboptimal. We report the response rate and outcome of two courses of vincristine/irinotecan/temsirolimus (VIT) in children with high-risk (HR)/metastatic HB.

PROCEDURES

Patients with newly diagnosed HB received HR window chemotherapy if they had metastatic disease or a serum alpha-fetoprotein (AFP) level less than 100 ng/mL. Patients received vincristine (days 1 and 8), irinotecan (days 1-5), and temsirolimus (days 1 and 8). Cycles were repeated every 21 days. Responders had either a 30% decrease using RECIST (Response Evaluation Criteria in Solid Tumors) criteria OR a 90% (>1 log10 decline) AFP decline after two cycles. Responders received two additional cycles of VIT intermixed with six cycles of cisplatin/doxorubicin/5-fluorouracil/vincristine (C5VD). Nonresponders received six cycles of C5VD alone.

RESULTS

Thirty-six eligible patients enrolled on study. The median age at enrollment was 27 months (range: 7-170). Seventeen of 36 patients were responders (RECIST and AFP = 3, RECIST only = 4, AFP only = 10). The median AFP at diagnosis was 222,648 ng/mL and the median AFP following two VIT cycles was 19,262 ng/mL. Three-year event-free survival was 47% (95% confidence interval [CI]: 30%-62%), while overall survival was 67% (95% CI: 49%-80%).

CONCLUSION

VIT did not achieve the study efficacy endpoint. Temsirolimus does not improve the response rate seen in patients treated with vincristine and irinotecan (VI) alone as part of the initial treatment regimen explored in this study. Additionally, AFP response may be a more sensitive predictor of disease response than RECIST in HB.

UBE2C expression is elevated in hepatoblastoma and correlates with inferior patient survival

Hepatoblastoma (HB) is the most common malignant liver tumor among children. To gain insight into the pathobiology of HB, we performed RNA sequence analysis on 5 patient-derived xenograft lines (HB-243, HB-279, HB-282, HB-284, HB-295) and 1 immortalized cell line (HUH6). Using cultured hepatocytes as a control, we found 2,868 genes that were differentially expressed in all of the HB lines on mRNA level. The most upregulated genes were ODAM, TRIM71, and IGDCC3, and the most downregulated were SAA1, SAA2, and NNMT. Protein-protein interaction analysis identified ubiquitination as a key pathway dysregulated in HB. UBE2C, encoding an E2 ubiquitin ligase often overexpressed in cancer cells, was markedly upregulated in 5 of the 6 HB cell lines. Validation studies confirmed UBE2C immunostaining in 20 of 25 HB tumor specimens versus 1 of 6 normal liver samples. The silencing of UBE2C in two HB cell models resulted in decreased cell viability. RNA sequencing analysis showed alterations in cell cycle regulation after UBE2C knockdown. UBE2C expression in HB correlated with inferior patient survival. We conclude that UBE2C may hold prognostic utility in HB and that the ubiquitin pathway is a potential therapeutic target in this tumor.

Occurrence of Hepatoblastomas in Patients with Beckwith-Wiedemann Spectrum (BWSp)

Patients with Beckwith-Wiedemann syndrome (BWS), an epigenetic imprinting disorder involving alterations in genes at the 11p15 chromosomal location, are predisposed to develop hepatoblastomas (HBs), which are rare embryonal liver tumors. Tumors can develop after a BWS diagnosis or, conversely, can be the presenting feature leading to a subsequent diagnosis. While HBs are the cardinal tumors of BWS, not all patients with the BWS spectrum will develop HBs. This observation has led to many hypotheses, including genotype-associated risk, tissue mosaicism, and tumor-specific second hits. To explore these hypotheses, we present the largest cohort of patients with BWS and HBs to date. Our cohort comprised 16 cases, and we broadened our sample size by searching the literature for all cases of BWS with HBs. From these isolated case studies, we amassed another 34 cases, bringing the total number to 50 cases of BWS-HB. We observed that paternal uniparental isodisomy (upd(11)pat) was the most common genotype, representing 38% of cases. The next most common genotype was IC2 LOM, representing 14% of cases. Five patients had clinical BWS without a molecular diagnosis. To investigate the potential mechanism of HBs in BWS, we analyzed normal liver and HB samples from eight cases and isolated tumor samples from another two cases. These samples underwent methylation testing, and 90% of our tumor samples underwent targeted cancer next-generation sequencing (NGS) panels. These matched samples provided novel insights into the oncogenesis of HBs in BWS. We found that 100% of the HBs that underwent NGS panel testing had variants in the CTNNB1 gene. We further identified three distinct groups of BWS-HB patients based on epigenotype. We also demonstrated epigenotype mosaicism, where 11p15 alterations can differ between the blood, HB, and normal liver. In light of this epigenotype mosaicism, tumor risk assessment based on blood profiling may not be accurate. Therefore, universal screening is recommended for all patients with BWS.

ACLY-β-catenin axis modulates hepatoblastoma cell proliferation

HB (hepatoblastoma) is most common in children with liver cancer and few options for treating HB. Thus, it is of great significance to investigate the regulatory mechanism of HB and/or identify new therapeutic targets for clinical treatment of HB. Here, we showed that ACLY (ATP citrate lyase), an important lipometabolic enzyme for de novo biosynthesis of fatty acids and steroids, has a higher expression in HB tissues than noncancerous tissues, and is required for HB cell proliferation. Moreover, knocking down ACLY in HB cells caused severe S-phase arrest and apoptosis. Mechanistically, ACLY knockdown significantly silenced the Wnt signaling pathway and reduced β-catenin expression in HB cells. Conversely, the apoptotic alleviation of HB cells by overexpressing ACLY was blocked by silencing β-catenin, suggesting the modulation of HB cells by ACLY-β-catenin axis. Our results uncovered the role of ACLY in HB cells and presented a theoretical approach for HB targeted therapy in the future.

Strategy for hepatoblastoma with major vascular involvement: A guide for surgical decision-making

BACKGROUND

Surgical management of tumor thrombus extending to the major vascular system for children with hepatoblastoma is challenging and insufficiently discussed.

METHODS

We conducted a retrospective review of hepatoblastoma with tumor thrombus extending to the major vascular system (inferior vena cava, 3 hepatic veins, and portal vein trunk) treated at our center between May 2010 and June 2021. We describe our preoperative assessment, surgical strategies, and outcomes.

RESULTS

We identified 9 patients (median age at the diagnosis: 3.4 years). All patients received chemotherapy before liver surgery. At the time of the diagnosis, tumor thrombus extended to the portal vein trunk (n = 6), inferior vena cava (n = 3), and 3 hepatic veins (n = 2). Among the 9 patients, 4 underwent liver resection. Liver transplantation was performed in 5 patients. The inferior vena cava wall was circumferentially resected for tumor removal in 1 patient and partially resected in 2 patients. One patient underwent liver transplantation using veno-venous bypass. Patients with tumor thrombus extending to the portal vein trunk were more likely to be managed by liver transplantation in comparison to those with tumor thrombus spreading to the inferior vena cava. The median follow-up period was 5.5 years. One patient underwent transhepatic balloon dilatation for biliary stricture after liver resection. Tumor recurrence was seen in 3 patients (33.3%; lung, n = 2; lymph node and liver, n = 1). No patients died during the follow-up period.

CONCLUSION

Surgical intervention for pediatric hepatoblastoma with tumor thrombus extending into the major vascular system is safe, feasible, and achieves excellent outcomes.

Surgical management in hepatoblastoma: points to take

Hepatoblastoma is the most common primary malignant paediatric liver tumour and surgery remains the cornerstone of its management. The aim of this article is to present the principles of surgical treatment of hepatoblastoma. All aspects of surgery in hepatoblastoma are discussed, from biopsy, through conventional and laparoscopic liver resections, to extreme resection with adjacent structures, staged hepatectomy and transplantation.

High-Resolution Magic-Angle-Spinning NMR in Revealing Hepatoblastoma Hallmarks

Cancer is one of the leading causes of death in children and adolescents worldwide; among the types of liver cancer, hepatoblastoma (HBL) is the most common in childhood. Although it affects only two to three individuals in a million, it is mostly asymptomatic at diagnosis, so by the time it is detected it has already advanced. There are specific recommendations regarding HBL treatment, and ongoing studies to stratify the risks of HBL, understand the pathology, and predict prognostics and survival rates. Although magnetic resonance imaging spectroscopy is frequently used in diagnostics of HBL, high-resolution magic-angle-spinning (HR-MAS) NMR spectroscopy of HBL tissues is scarce. Using this technique, we studied the alterations among tissue metabolites of ex vivo samples from (a) HBL and non-cancer liver tissues (NCL), (b) HBL and adjacent non-tumor samples, and (c) two regions of the same HBL samples, one more centralized and the other at the edge of the tumor. It was possible to identify metabolites in HBL, then metabolites from the HBL center and the border samples, and link them to altered metabolisms in tumor tissues, highlighting their potential as biochemical markers. Metabolites closely related to liver metabolisms such as some phospholipids, triacylglycerides, fatty acids, glucose, and amino acids showed differences between the tissues.

Role of Diffusion Weighted MRI (DW-MR) in Detection of Satellite Lesions Not Detected with Multiphase CT Scans in Hepatoblastoma and Its Implications for Management

OBJECTIVE

To evaluate the role of diffusion-weighted magnetic resonance imaging (DW-MR) in hepatoblastoma as compared to multiphase contrast enhanced computed tomography (CECT) scans for detection of satellite lesions.

METHODS

In this prospective study on new cases of hepatoblastoma, multiphase CECT scans and DW-MR were performed before initiation of chemotherapy. Results of interpretation were compared for detection of satellite lesions. PRETEXT grouping and risk categorization was done according to SIOPEL based on CECT scan.

RESULTS

Nine boys and 1 girl with hepatoblastoma, with median age of 11.5 mo were included. All patients were stratified as high-risk group with 2 (20%) in PRETEXT II and 8 (80%) in PRETEXT III. In 2 of 10 (20%) patients, additional satellite lesions were detected on DW-MR, which upgraded their stage. One of the two patients had one satellite lesion identified on CECT, while additional seven satellite lesions were identified on DW-MR imaging. For the other patient, CECT showed no satellite lesion while DW-MR detected six satellite lesions.

CONCLUSION

MRI has become the gold standard investigation for evaluation of hepatoblastoma. DW-MR, which is a contrast free technique, is a better tool for assessment of satellite lesions which are usually missed on CECT. This would help in proper staging, planning of management and prognostication.

Incidence and 5-year survival of children and adolescents with hepatoblastoma in the United States

OBJECTIVE

Hepatoblastoma (HB) is the most common pediatric primary malignant liver tumor, its incidence has been increasing worldwide, but recent changes in incidence and outcomes with high population coverage are not well characterized.

METHODS

We defined the incidence of HB diagnosed during 2003-2017 from United States Cancer Statistics (USCS) database, and survival during 2001-2016 from the National Program of Cancer Registries (NPCR). Data were stratified by sex, race/ethnicity, age, tumor stage, county population, and diagnosis year. Incidence trends were assessed by calculating average annual percent change (AAPC) using Joinpoint regression. Differences in overall 5-year survival were estimated using Cox regression analysis.

RESULTS

2178 HB cases with an annual incidence rate of 1.76 per million persons were identified and incidence increased over time (AAPC = 2.2, 95% confidence interval [CI], 0.9-3.6). The 5-year relative survival was 76.9% (95% CI: 74.9-78.8) and the risk of death was lower for cases diagnosed after 2009 (hazard ratio [HR] = 0.77, 95% CI: 0.63-0.94), higher for ages 3-7 years and 8-19 years compared to 0-2 years (HR = 1.38, 95% CI: 1.10-1.76 and 1.83, 95% CI: 1.31-2.70, respectively), for distant compared to locoregional stage (HR = 2.77, 95% CI: 2.27-3.36), and for non-Hispanic Black compared to non-Hispanic White cases (HR = 1.39, 95% CI: 1.02-1.84).

CONCLUSIONS

HB incidence increased, and survival improved over the study period. Disparities in survival exist by age, race or ethnicity, and stage. Further studies could identify factors affecting increases in HB cases, inform future interventions, and address disparities in outcomes.

Oncogenic Role of ADAM32 in Hepatoblastoma: A Potential Molecular Target for Therapy

Outcomes of pediatric hepatoblastoma (HBL) have improved, but refractory cases still occur. More effective and safer drugs are needed that are based on molecular mechanisms. A disintegrin and metalloproteases (ADAMs) are expressed with high frequency in various human carcinomas and play an important role in cancer progression. In this study, we analyzed expression of ADAMs in HBL with a cDNA microarray dataset and found that the expression level of ADAM32 is particularly high. To investigate the role of ADAM32 in cancer, forced expression or knockdown experiments were conducted with HepG2 and HBL primary cells. Colony formation, cell migration and invasion, and cell viability were increased in HepG2 expressing ADAM32, whereas knockdown of ADAM32 induced a decrease in these cellular functions. Quantitative RT-PCR demonstrated an association between ADAM32 expression and the expression of genes related to cancer stem cells and epithelial–mesenchymal transition (EMT), suggesting a role of ADAM32 in cancer stemness and EMT. Furthermore, knockdown of ADAM32 increased cisplatin-induced apoptosis, and this effect was attenuated by a caspase-8 inhibitor, suggesting that ADAM32 plays a role in extrinsic apoptosis signaling. We conclude that ADAM32 plays a crucial role in progression of HBL, so it might be a promising molecular target in anticancer therapy.

Histologic type predicts disparate outcomes in pediatric hepatocellular neoplasms: A Pediatric Surgical Oncology Research Collaborative study

BACKGROUND

Hepatocellular carcinoma (HCC) is a rare cancer in children, with various histologic subtypes and a paucity of data to guide clinical management and predict prognosis.

METHODS

A multi-institutional review of children with hepatocellular neoplasms was performed, including demographic, staging, treatment, and outcomes data. Patients were categorized as having conventional HCC (cHCC) with or without underlying liver disease, fibrolamellar carcinoma (FLC), and hepatoblastoma with HCC features (HB-HCC). Univariate and multivariate analyses identified predictors of mortality and relapse.

RESULTS

In total, 262 children were identified; and an institutional histologic review revealed 110 cHCCs (42%; 69 normal background liver, 34 inflammatory/cirrhotic, 7 unknown), 119 FLCs (45%), and 33 HB-HCCs (12%). The authors observed notable differences in presentation and behavior among tumor subtypes, including increased lymph node involvement in FLC and higher stage in cHCC. Factors associated with mortality included cHCC (hazard ratio [HR], 1.63; P = .038), elevated α-fetoprotein (HR, 3.1; P = .014), multifocality (HR, 2.4; P < .001), and PRETEXT (pretreatment extent of disease) stage IV (HR, 5.76; P < .001). Multivariate analysis identified increased mortality in cHCC versus FLC (HR, 2.2; P = .004) and in unresectable tumors (HR, 3.4; P < .001). Disease-free status at any point predicted survival.

CONCLUSIONS

This multi-institutional, detailed data set allowed a comprehensive analysis of outcomes for children with these rare hepatocellular neoplasms. The current data demonstrated that pediatric HCC subtypes are not equivalent entities because FLC and cHCC have distinct anatomic patterns and outcomes in concert with their known molecular differences. This data set will be further used to elucidate the impact of histology on specific treatment responses, with the goal of designing risk-stratified algorithms for children with HCC.

LAY SUMMARY

This is the largest reported granular data set on children with hepatocellular carcinoma. The study evaluates different subtypes of hepatocellular carcinoma and identifies key differences between subtypes. This information is pivotal in improving understanding of these rare cancers and may be used to improve clinical management and subsequent outcome in children with these rare malignancies.

Clinical Application of Indocyanine Green Fluorescence Imaging in the Resection of Hepatoblastoma: A Single Institution's Experiences

Purpose

Indocyanine green (ICG) fluorescence imaging is becoming increasingly popular in adult oncologic surgery, but remains relatively uncommon in pediatric oncologic surgery. Herein, we report our experience with the use of ICG fluorescence imaging in the resection of hepatoblastoma (HB).

Patients and Methods

Hepatoblastoma patients who underwent liver resection with ICG fluorescence imaging between January 2020 and March 2021 were included in this study. Patients’ demographic data, clinical information, and detailed information of the use of ICG fluorescence imaging were retrospectively reviewed.

Results

Sixteen HB patients underwent ICG fluorescence imaging-guided liver resection. There were 11 males and 5 females, age ranged from 8 to 134 months. The initial alpha-fetoprotein ranged from 436 to 528,390 ng/ml. There were one pre-treatment extent of tumor stage I, nine stage II, four stage III, and two stage IV. Three patients underwent up-front hepatectomy, 13 patients received 2–8 cycles of platinum-based neoadjuvant chemotherapy and underwent delayed hepatectomy. ICG (0.5 mg/kg) was given intravenously 48–72 h prior to surgery. The operative time ranged from 180 to 400 min. All patients achieved negative surgical margins. In two patients, ICG identify additional lesions which were not detected in preoperative imaging.

Conclusion

ICG fluorescence imaging is useful in the resection of HB and may detect small lesions not shown in preoperative imaging.

Second Generation Small Molecule Inhibitors of Gankyrin for the Treatment of Pediatric Liver Cancer

Background: Gankyrin, a member of the 26S proteasome, is an overexpressed oncoprotein in hepatoblastoma (HBL) and hepatocellular carcinoma (HCC). Cjoc42 was the first small molecule inhibitor of Gankyrin developed; however, the IC50 values of >50 μM made them unattractive for clinical use. Second-generation inhibitors demonstrate a stronger affinity toward Gankyrin and increased cytotoxicity. The aim of this study was to characterize the in vitro effects of three cjoc42 derivatives. Methods: Experiments were performed on the HepG2 (HBL) and Hep3B (pediatric HCC) cell lines. We evaluated the expression of TSPs, cell cycle markers, and stem cell markers by Western blotting and/or real-time quantitative reverse transcription PCR. We also performed apoptotic, synergy, and methylation assays. Results: The treatment with cjoc42 derivatives led to an increase in TSPs and a dose-dependent decrease in the stem cell phenotype in both cell lines. An increase in apoptosis was only seen with AFM-1 and -2 in Hep3B cells. Drug synergy was seen with doxorubicin, and antagonism was seen with cisplatin. In the presence of cjoc42 derivatives, the 20S subunit of the 26S proteasome was more available to transport doxorubicin to the nucleus, leading to synergy. Conclusion: Small-molecule inhibitors for Gankyrin are a promising therapeutic strategy, especially in combination with doxorubicin.

Primary Malignant Liver Tumors: eight-year experience in a Pediatric Hospital in Brazil. A cross-sectional study

INTRODUCTION

liver tumors are rare neoplasms in childhood (1-2%), and about 2/3 are malignant. Hepatoblastoma (HB) is the most frequent, followed by hepatocellular carcinoma (HCC). In both, the main treatment is surgical resection. Currently, chemotherapy and liver transplantation have improved outcomes.

OBJECTIVE

study of the epidemiological profile and evolution of liver cancer cases in a referral pediatric hospital.

METHODOLOGY

a retrospective survey of medical records of patients aged up to 18 years with a diagnosis of primary malignant hepatic neoplasm between 2012 and 2020, carried out in the largest exclusively pediatric hospital in Brazil.

RESULTS

a total of 13 patients with malignant liver tumors (HB 12, HCC 1) were treated. Of the HB cases, 66,7% were male, with a mean age of 2 years and the main alteration in the palpable abdominal mass. Tumors involved an average of 3 liver segments, more in the right lobe (54%). Only one patient was treated with surgery without neoadjuvant therapy, another one underwent transplantation like the first treatment, and another 2 required liver transplantation as a rescue. The middle follow-up time of patients with HB was 39 months and only 1 case died due to febrile neutropenia. The 5-year overall and disease-free survival was 91.7% and 81.5%, respectively.

CONCLUSION

Advanced staging at the time of diagnosis has always been a poor prognostic factor in patients with primary malignant liver tumors. However, the results and survival have improved with the advancement of chemotherapy, surgical technique, and liver transplantation.

Extracellular Vesicles: A New Source of Biomarkers in Pediatric Solid Tumors? A Systematic Review

Virtually every cell in the body releases extracellular vesicles (EVs), the contents of which can provide a "fingerprint" of their cellular origin. EVs are present in all bodily fluids and can be obtained using minimally invasive techniques. Thus, EVs can provide a promising source of diagnostic, prognostic, and predictive biomarkers, particularly in the context of cancer. Despite advances using EVs as biomarkers in adult cancers, little is known regarding their use in pediatric cancers. In this review, we provide an overview of published clinical and in vitro studies in order to assess the potential of using EV-derived biomarkers in pediatric solid tumors. We performed a systematic literature search, which yielded studies regarding desmoplastic small round cell tumor, hepatoblastoma, neuroblastoma, osteosarcoma, and rhabdomyosarcoma. We then determined the extent to which the in vivo findings are supported by in vitro data, and vice versa. We also critically evaluated the clinical studies using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) system, and we evaluated the purification and characterization of EVs in both the in vivo and in vitro studies in accordance with MISEV guidelines, yielding EV-TRACK and PedEV scores. We found that several studies identified similar miRNAs in overlapping and distinct tumor entities, indicating the potential for EV-derived biomarkers. However, most studies regarding EV-based biomarkers in pediatric solid tumors lack a standardized system of reporting their EV purification and characterization methods, as well as validation in an independent cohort, which are needed in order to bring EV-based biomarkers to the clinic.

Seventeen Years of Pediatric Liver Transplantation Experience for Cirrhosis and Hepatocellular Carcinoma

OBJECTIVES

This was a retrospective analysis of liver transplant for pediatric patients with liver cirrhosis and hepatocellular carcinoma.

MATERIALS AND METHODS

Fourteen pediatric patients with chronic liver disease and hepatocellular carcinoma underwent liver transplant from 2004 to 2021. Preexisting diseases were tyrosinemia (n = 6), progressive familial intrahepatic cholestasis type 2 (n = 2) and type 3 (n = 3), cryptogenic cirrhosis (n = 2), hepatitis B and D (n = 1), and biliary atresia (n = 1).

RESULTS

Mean age was 9.43 ± 4.9 years (range, 13 months to 16 years). Three patients had 1 tumor, 4 had 2 tumors, and 7 had multiple (≥3) lesions. Six patients were classified as Pretreatment Extent of Disease Staging System for Hepatoblastoma (PRETEXT) stage IV, 3 as stage II, and 5 as stage I. Some patients received systemic chemotherapy before (n = 4) or after transplant (n = 3) or transarterial chemoembolization and microwave ablation pretransplant (n = 1). Hepatocellular carcinoma posttransplant recurrence was observed at 23, 47, and 108 months in 3 patients (21%). Recurrence sites were omentum (n = 1) and liver graft (n = 2). One patient was treated with hepatic resection, radiofrequency ablation, and radiotherapy, while the other received radiofrequency ablation and chemotherapy for graft tumor recurrence. Relapse-free patient survival rates were 92%, 82.5%, and 72.2% at 2, 4, and 10 years, respectively. Four recipients (28.5%) died; posttransplant cause of death was infection at 19 (n = 1) and 188 months (n = 1) or hepatocellular carcinoma recurrence at 79 (n = 1) and 165 months (n = 1). Median follow-up was 178 months (range, 13-204 months). Mean estimated survival was 171.25 ± 16.6 months. Overall patient posttransplant survival was 100%, 92.3%, 92.3%, 83%, and 72% at 1, 2, 5, 10, and 15 years, respectively.

CONCLUSIONS

Hepatocellular carcinoma was mainly associated with inherited liver diseases in our pediatric series. Liver transplant provided a long-term survival advantage to pediatric patients with preexisting cirrhosis and hepatocellular carcinoma.

Trans-Arterial Radioembolization with Yttrium-90 of Unresectable and Systemic Chemotherapy Resistant Hepatoblastoma in Three Toddlers

The aim of this short communication was to report the results of transarterial radioembolization (TARE) with Yttrium-90 (Y90) loaded resin microspheres in three toddlers with unresectable and systemic chemotherapy-resistant HB hepatoblastoma (HB). Six TARE procedures were performed on the patients. The dose required for treatment was calculated using partition model. Administered doses of Y90 were 1.369, 0.851, and 1.147 GBq. Complete radiological response in two patients and partial response enabling liver resection in one patient were achieved. Neither life-threatening nor minor complications developed after the treatment. These results demonstrates that HB is a radiosensitive neoplasm, and TARE-Y90 can be used as the primary, neoadjuvant and palliative treatment method in patients with unresectable and systemic chemotherapy-resistant HBs. However, studies with higher number of patients and long-term results are required.

Doxorubicin in combination with cisplatin, 5-flourouracil, and vincristine is feasible and effective in unresectable hepatoblastoma: A Children's Oncology Group study

BACKGROUND

The Children's Oncology Group (COG) adopted cisplatin, 5-flourouracil, and vincristine (C5V) as standard therapy after the INT-0098 legacy study showed statistically equivalent survival but less toxicity in comparison with cisplatin and doxorubicin. Subsequent experience demonstrated doxorubicin to be effective in patients with recurrent disease after C5V, and this suggested that it could be incorporated to intensify therapy for patients with advanced disease.

METHODS

In this nonrandomized, phase 3 COG trial, the primary aim was to explore the feasibility and toxicity of a novel therapeutic cisplatin, 5-flourouracil, vincristine, and doxorubicin (C5VD) regimen with the addition of doxorubicin to C5V for patients considered to be at intermediate risk. Patients were eligible if they had unresectable, nonmetastatic disease. Patients with a complete resection at diagnosis and local pathologic evidence of small cell undifferentiated histology were also eligible for an assessment of feasibility.

RESULTS

One hundred two evaluable patients enrolled between September 14, 2009, and March 12, 2012. Delivery of C5VD was feasible and tolerable: the mean percentages of the target doses delivered were 96% (95% CI, 94%-97%) for cisplatin, 96% (95% CI, 94%-97%) for 5-fluorouracil, 95% (95% CI, 93%-97%) for doxorubicin, and 90% (95% CI, 87%-93%) for vincristine. Toxicity was within expectations, with death as a first event in 1 patient. The most common adverse events were febrile neutropenia (n = 55 [54%]), infection (n = 48 [47%]), mucositis (n = 31 [30%]), hypokalemia (n = 39 [38%]), and elevated aspartate aminotransferase (n = 28 [27%]). The 5-year event-free and overall survival rates for the 93 patients who did not have complete resection at diagnosis were 88% (95% CI, 79%-93%) and 95% (95% CI, 87%-98%), respectively.

CONCLUSIONS

The addition of doxorubicin to the previous standard regimen of C5V is feasible, tolerable, and efficacious, and this suggests that C5VD is a good regimen for future clinical trials.

Diagnosis and Follow-up of Incidental Liver Lesions in Children

Incidental liver lesions are identified in children without underlying liver disease or increased risk of hepatic malignancy in childhood. Clinical and imaging evaluation of incidental liver lesions can be complex and may require a multidisciplinary approach. This review aims to summarize the diagnostic process and follow-up of incidental liver lesions based on review of the literature, use of state-of-the-art imaging, and our institutional experience. Age at presentation, gender, alpha fetoprotein levels, tumor size, and imaging characteristics should all be taken into consideration to optimize diagnosis process. Some lesions, such as simple liver cyst, infantile hemangioma, focal nodular hyperplasia (FNH), and focal fatty lesions, have specific imaging characteristics. Recently, contrast-enhanced ultrasound (CEUS) was Food and Drug Administration (FDA)-approved for the evaluation of pediatric liver lesions. CEUS is most specific in lesions smaller than 3 cm and is most useful in the diagnosis of infantile hemangioma, FNH, and focal fatty lesions. The use of hepatobiliary contrast in MRI increases specificity in the diagnosis of FNH. Recently, lesion characteristics in MRI were found to correlate with subtypes of hepatocellular adenomas and associated risk for hemorrhage and malignant transformation. Biopsy should be considered when there are no specific imaging characteristics of a benign lesion. Surveillance with imaging and alpha fetoprotein (AFP) should be performed to confirm the stability of lesions when the diagnosis cannot be determined, and whenever biopsy is not feasible.

A large undifferentiated sarcoma of the liver in a 13-year-old girl treated with anatomical resection: a case report and review of the literature

Background

Undifferentiated embryonal sarcoma of the liver (UESL) is a rare liver tumor accounting for 6–13% of primary liver tumors. Accurate preoperative diagnosis is difficult, with a rather high misdiagnosis rate. Herein, we reported a very large UESL treated with anatomical resection. Our case is amongst the largest pediatric UESLs in the literature.

Case presentation

Herein, we report a 13-year-old girl presenting with right upper quadrant abdominal pain, postprandial vomiting, and abdominal distention, in which radiographic imaging demonstrated a huge UESL (28 × 20 × 12 cm). The patient was treated with partial hepatectomy and the 5 kg tumor was removed. The patient was discharged in good condition, with no significant complaints in her follow-up.

Conclusions

Although different treatment strategies have been reported for UESL cases, anatomical resection is still the main treatment approach, especially for large tumors.

Neoplasias Malignas Primárias do Fígado: experiência de oito anos de um Hospital Pediátrico no Brasil. Estudo transversal

RESUMO Introdução: tumores hepáticos são neoplasias raras na infância (1-2%), sendo que cerca de 2/3 são malignos. O hepatoblastoma (HB) é o mais frequente, seguido do carcinoma hepatocelular (CHC). Em ambos, o principal tratamento é a ressecção cirúrgica completa. Atualmente, a quimioterapia e o transplante hepático têm melhorado os resultados. Objetivo: estudo do perfil epidemiológico e evolução dos casos de cânceres hepáticos em um hospital pediátrico de referência. Método: Levantamento retrospectivo de prontuários de pacientes até 18 anos com diagnóstico de neoplasia maligna primária hepática entre 2012 e 2020 realizado no maior hospital exclusivamente pediátrico do Brasil. Resultados: foram atendidos 13 pacientes com tumores malignos hepáticos (HB 12, CHC 1). Dos casos de HB, 66,7% eram do sexo masculino, com idade média de 2 anos e a principal alteração foi massa abdominal palpável. Os tumores envolviam em média 3 segmentos hepáticos, mais em lobo direito (54%). Um paciente foi tratado com cirurgia sem neoadjuvância, um foi submetido a transplante inicialmente e outros 2 necessitaram de transplante hepático como resgate. O tempo de seguimento dos pacientes com HB foi de 39 meses e apenas 1 caso foi a óbito por neutropenia febril. A sobrevida geral e livre de doença em 5 anos foi de 91,7% e 81,5% respectivamente. Conclusão: o estadiamento avançado no momento do diagnóstico sempre foi um fator de mau prognóstico em pacientes com tumores hepáticos malignos primários. Entretanto, os resultados e a sobrevida têm melhorado significativamente com o avanço da quimioterapia, da técnica cirúrgica e do transplante hepático.

Tumor-Background Ratio is an effective method to identify tumors and false-positive nodules in indocyanine-green navigation surgery for pediatric liver cancer

BACKGROUND

Indocyanine green (ICG) navigation surgery has been used for hepatoblastoma (HB) in children but the technique has been reported for using in other childhood liver cancers were rare. This article summarizes the application experience of ICG in HB and other childhood liver cancers in children and explores the role of fluorescence intensity measurement in identifying tumors.

METHODS

To summarize the clinical experience of children with liver cancer treated by ICG navigation surgery. The tumor and its surrounding tissue were photographed by near infrared during the operation. The fluorescence intensity of tumors, ICG (+) lesions and the normal liver was measured, and the Tumor-Background Ratio (TBR) was calculated.

RESULTS

A total of 11 children with liver cancer were injected intravenously with ICG 1 day before operation. With the help of ICG fluorescence navigation, there was no residual tumor at the surgical margin for all the children. Total fluorescence was seen in 2 cases, rim fluorescence in 2 cases, and partial fluorescence in 7 cases. 19 ICG false-positive nodules were found on the resection stump or residual liver tissue in 5 cases, and the TBR value of tumors was higher than that of false- positive nodules. 10 children have survived without disease.

CONCLUSION

ICG navigation surgery is safe and feasible for liver cancer in children, which can enhance the visualization of the tumor during operation and provide more information about the location and boundaries of the tumor. This technique also has limitations, which can be affected by chemotherapy, tumor location, ICG administration regimen, and equipment. TBR is an effective method to identify tumor and non-cancerous lesions.

Living donor liver transplantation for hepatic malignancies in children

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Genetic and epigenetic basis of hepatoblastoma diversity

Hepatoblastoma (HB) is the most common pediatric liver malignancy; however, hereditary predisposition and acquired molecular aberrations related to HB clinicopathological diversity are not well understood. Here, we perform an integrative genomic profiling of 163 pediatric liver tumors (154 HBs and nine hepatocellular carcinomas) based on the data acquired from a cohort study (JPLT-2). The total number of somatic mutations is precious low (0.52/Mb on exonic regions) but correlated with age at diagnosis. Telomerase reverse transcriptase (TERT) promoter mutations are prevalent in the tween HBs, selective in the transitional liver cell tumor (TLCT, > 8 years old). DNA methylation profiling reveals that classical HBs are characterized by the specific hypomethylated enhancers, which are enriched with binding sites for ASCL2, a regulatory transcription factor for definitive endoderm in Wnt-pathway. Prolonged upregulation of ASCL2, as well as fetal-liver-like methylation patterns of IGF2 promoters, suggests their "cell of origin" derived from the premature hepatoblast, similar to intestinal epithelial cells, which are highly proliferative. Systematic molecular profiling of HB is a promising approach for understanding the epigenetic drivers of hepatoblast carcinogenesis and deriving clues for risk stratification.

Establishing a Standardized Measure of Quality in Pediatric Liver Surgery: Definition and Validation of Textbook Outcome With Associated Predictors

Purpose: To establish comparable reporting of surgical results in pediatric liver surgery, the recently introduced composite outcome measures Textbook Outcome (TO) and Comprehensive Complication Index (CCI) are applied and validated in a pediatric surgery context for the first time. In a representative cohort of pediatric patients undergoing liver resection, predictive factors for TO and CCI are investigated, and outcomes are compared to available literature on surgical outcomes of pediatric liver resection.

Methods: All liver resections for patients under 21 years of age performed at the Department of General, Visceral, Transplantation and Pediatric Surgery of the University of Heidelberg between 2009 and 2020 were included in the analysis. Criteria for TO were defined prior to the analysis. Univariate and Multivariate regression was applied to identify factors associated with TO and CCI.

Results: Fifty-three pediatric patients underwent liver resections during the observation period. No 30- or 90-day mortality occurred. Twenty-three patients (43.4%) had a TO. CCI and TO showed highly significant correlation (b = −30.33, 95% CI [−37.44; −23.22], p < 0.001). Multivariate analyses revealed significant association between intraoperative blood loss (adjusted for circulating blood volume) and CCI (b = 0.70, 95%CI [0.22; 1.32], p = 0.008) and failure to achieve TO (OR = 0.85, 95%CI [0.69; 0.97], p = 0.048).

Conclusion: TO and CCI are suited outcome measures in pediatric surgical studies and offer objective comparability of results. Their application in clinical studies will be a major step forward to establish evidence-based therapies in pediatric surgery. Systematic utilization of TO and CCI can aid in generating comparable studies on surgical techniques and outcomes in pediatric liver resection.

Pursuing Precision: Receptor Tyrosine Kinase Inhibitors for Treatment of Pediatric Solid Tumors

Receptor tyrosine kinases are critical for the growth and proliferation of many different cancers and therefore represent a potential vulnerability that can be therapeutically exploited with small molecule inhibitors. Over forty small molecule inhibitors are currently approved for the treatment of adult solid tumors. Their use has been more limited in pediatric solid tumors, although an increasing number of single-agent and combination studies are now being performed. These agents have been quite successful in certain clinical contexts, such as the treatment of pediatric tumors driven by kinase fusions or activating mutations. By contrast, only modest activity has been observed when inhibitors are used as single agents for solid tumors that do not have genetically defined alterations in the target genes. The absence of predictive biomarkers has limited the wider applicability of these drugs and much work remains to define the appropriate patient population and clinical situation in which receptor tyrosine kinase inhibitors are most beneficial. In this manuscript, we discuss these issues by highlighting past trials and identifying future strategies that may help add precision to the use of these agents for pediatric extracranial solid tumors.

Central Hepatectomy in a 6-Month-Old Child with Hepatoblastoma following Chemotherapy

A hepatoblastoma in a 6-month-old child was initially considered unresectable because of diffuse liver involvement. The patient received 4 courses of cisplatin with an interval time of 2 weeks. A computed tomography scan after 4 courses of chemotherapy showed shrinking of the tumor, which made it resectable, and the tumor was removed by central hepatectomy. The patient was able to eat a regular diet on the fourth day and was sent home on the seventh day, after the operation. The pediatric oncologist followed the patient with liver ultrasonography and alpha-fetoprotein and administered 2 more cycles of cisplatin.

[Imaging of hepatic tumors in children and adolescents]

BACKGROUND

Pediatric liver tumors are relatively rare, but thorough knowledge of their imaging features is still important.

OBJECTIVES

Frequency and imaging features of benign and malignant liver masses during childhood and adolescence.

MATERIALS AND METHODS

Discussion of relevant original articles, review manuscripts and expert recommendations concerning imaging of childhood liver tumors.

RESULTS

The most common malignant tumors of the liver are hepatoblastoma, which usually occur in younger children, as well as in some regions hepatocellular carcinoma. In contrast to most benign masses, such as focal nodular hyperplasia, simple cysts or fatty liver infiltrations, their imaging morphology is not very characteristic. Radiologically, sonography and magnetic resonance imaging (MRI) are used for assessment. Both methods benefit from intravenous contrast agent administration.

CONCLUSIONS

Childhood liver tumors show a broad spectrum of morphological manifestations. Some entities can be characterized using standard imaging, some require multimodal imaging or histological assessment. In addition to morphological imaging criteria, age and the medical history as well as laboratory data play an important role in establishing the correct diagnosis.

Liver Tumors in Pediatric Patients

The most recent advance in the care of children diagnosed with hepatoblastoma and hepatocellular carcinoma is the Pediatric Hepatic International Tumor Trial, which opened to international enrollment in 2018. It is being conducted as a collaborative effort by the pediatric multicenter trial groups in North America, Europe, and the Far East. This international effort was catalyzed by a new unified global risk stratification system for hepatoblastoma, an international histopathologic consensus classification for pediatric liver tumors, and a revised 2017 collaborative update of the PRE-Treatment EXTent of disease radiographic based staging system.

Small Molecule Cjoc42 Improves Chemo-Sensitivity and Increases Levels of Tumor Suppressor Proteins in Hepatoblastoma Cells and in Mice by Inhibiting Oncogene Gankyrin

Objective: Relapsed hepatoblastoma (HBL) and upfront hepatocellular carcinoma (HCC) are notoriously chemoresistant tumors associated with poor outcomes. Gankyrin (Gank) is a known oncogene that is overexpressed in pediatric liver cancer and implicated in chemo-resistance. The goal of this study was to evaluate if the Gank-tumor suppressor axis is activated in chemoresistant hepatoblastoma patients and examine if an inhibitor of Gank, Cjoc42, might improve the chemosensitivity of cancer cells.

Methods: Expression of Gank and its downstream targets were examined in fresh human HBL samples using immunostaining, QRT-PCR, and Western Blot. Cancer cells, Huh6 (human HBL) and Hepa1c1c7 (mouse HCC) were treated with Cjoc42 and with Cjoc42 in combination with cisplatin or doxorubicin. Cell proliferation, apoptosis, and chemoresistance were examined. To examine activities of Cjoc42 in vivo, mice were treated with different doses of Cjoc42, and biological activities of Gank and cytotoxicity of Cjoc42 were tested.

Results: Elevation of Gank and Gank-mediated elimination of TSPs are observed in patients with minimal necrosis after chemotherapy and relapsed disease. The treatment of Huh6 and Hepa1c1c7 with Cjoc42 was not cytotoxic; however, in combination with cisplatin or doxorubicin, Cjoc42 caused a significant increase in cytotoxicity compared to chemotherapy alone with increased apoptosis. Examination of Cjoc42 in WT mice showed that Cjoc42 is well tolerated without systemic toxicity, and levels of tumor suppressors CUGBP1, Rb, p53, C/EBPα, and HNF4α are increased by blocking their Gank-dependent degradation.

Conclusions: Our work shows that Cjoc42 might be a promising adjunct to chemotherapy for the treatment of severe pediatric liver cancer and presents mechanisms by which Cjoc42 increases chemo-sensitivity.

Liver Transplantation in Locally Unresectable, Undifferentiated Embryonal Cell Sarcoma

Background.

Undifferentiated embryonal cell sarcoma (UESL) of the liver is the third most common malignant liver disease of childhood presenting as a rapidly enlarging intraabdominal mass. This systematic review explores the practicality of liver transplantation as a viable option in the treatment armamentarium for locally advanced undifferentiated embryonal cell sarcoma.

Methods.

A systematic review of the literature was performed using Medline and Embase, from inception of databases to December 31, 2018. Keywords and MeSH headings used were embryonal sarcoma, mesenchymal sarcoma, and liver transplant. Reviews and manuscripts with incomplete data were excluded.

Results.

Twenty-eight patients had orthotopic liver transplantation (OLT) as a curative treatment option. The median age at presentation was 8 and 27 years in the pediatric and adult population, respectively, with a similar male to female ratio. A majority of the patients presented with abdominal pain, palpable mass, and a normal alpha-feto-protein. The median tumor size was 15 cm mainly affecting the right lobe (62%) of the liver. Eighty-two percent of the patients underwent primary OLT and 5 patients had salvage OLT. One death (3.6%) was due to initial misdiagnosis and management for hepatoblastoma. Recurrence was noted in 7.1% of the population. The median follow-up was noted to be 28.5 months. The documented survival rate post-liver transplant for UESL was 96%.

Conclusions.

Based on available data and the very positive results therein, liver transplantation is a practical and justifiable use of a scarce resource as a treatment option for locally unresectable, undifferentiated embryonal cell sarcoma. The authors propose (accepting existence of different proposals) neoadjuvant therapy before curative resection, and if not achievable, then liver transplantation followed by adjuvant chemotherapy is an option for suitable candidates. For recurrent tumors after surgical resection, adjuvant therapy with salvage liver transplantation is an option.

Neuropilin-2 Is Associated With Increased Hepatoblastoma Cell Viability and Motility

The neuropilins NRP1 and NRP2 are multifunctional glycoproteins that have been implicated in several cancer-related processes including cell survival, migration, and invasion in various tumor types. Here, we examine the role of neuropilins in hepatoblastoma (HB), the most common pediatric liver malignancy. Using a combination of immunohistochemistry, RNA analysis and western blotting, we observed high level expression of NRP1 and NRP2 in 19 of 20 HB specimens and in a majority of human HB cell lines (HUH6 and five cell lines established from patient-derived xenografts) studied but not in normal hepatocytes. Silencing of NRP2 expression in HUH6 and HB-282 HB cells resulted in decreased cell viability, impaired cytoskeleton remodeling, and reduced cell motility, suggesting that NRP2 contributes to the malignant phenotype. We propose that neuropilins warrant further investigation as biomarkers of HB and potential therapeutic targets.

A narrative review of the challenges and countermeasures in hepatoblastoma management during COVID-19 epidemic

An infectious disease named "coronavirus disease 2019" (COVID-19) currently has brought a threat to global health security and trends to be more and more severe in many countries. It also has introduced great challenges to the diagnosis and management of children with hepatoblastoma (HB). During the COVID-19 pandemic, pediatric surgeons should not only develop personalized treatment plans for HB therapy, but also emphasize the diagnosis, prevention, and treatment of this virus. Children with both HB and COVID-19 are recommended to undertake multidisciplinary assessment. Anti-SARS-CoV-2 therapy may be a preferred treatment for the infected without presenting a surgical emergency. However, emergent operation may be necessary for HB children with concurrent COVID-19 who developed a life-threatening surgical emergency condition. Otherwise, for children with negative virus examination results, treatment advice should be based on the impact of the epidemic and regional economic considerations. A "wait and see" strategy is recommended for children with resectable tumors after new adjuvant chemotherapy treatment (NACT). Assessment of liver transplantation is recommended for children with HB whose tumors cannot be resected after NACT. Children with HB with pulmonary metastasis may have abnormal findings on chest imaging due to COVID-19. Besides, the detailed therapeutic regimens may vary for children with HB with or without an emergency presentation. Based on previous consensus, current research, and the experiences of our hospital, we aim to offer available management plans for the above-mentioned concerns.

Pediatric hepatic cancer incidence and survival: 30-year trends in Ontario, Canada; the United States; and Australia

BACKGROUND

Pediatric hepatic cancer is a rare malignancy, comprising only approximately 2% of all cancers diagnosed in children aged <15 years. The authors sought to describe trends in pediatric hepatic cancer incidence and survival in Ontario, Canada; the United States; and Australia.

METHODS

Children aged <15 years who were diagnosed with hepatic cancer from 1985 through 2013 were ascertained through population-based registries and followed from the time of diagnosis until December 31, 2015. Age-standardized incidence and 5-year relative survival were calculated for each jurisdiction. Multivariable flexible parametric survival models were used to explore predictors of hepatic cancer mortality.

RESULTS

A total of 794 children were identified in Ontario (148 children), the United States (400 children), and Australia (246 children). The average annual incidence increased by 2.2% (95% CI, 0.5%-4.0%) in Australia, 2.1% (95% CI, 0.9%-3.3%) in the United States, and 1.3% (95% CI, -0.4% to 3.0%) in Ontario. The 5-year relative survival rate improved from 60% to 82% (P = .08) in Ontario and 62% to 78% (P = .02) in the United States between the diagnostic periods 1985 through 1994 and 2005 through 2013, whereas in Australia the rate remained constant (between 74% and 77%) during the study period. On multivariable analysis, there was no significant difference noted with regard to the hazard of death between jurisdictions (P = .06). Older age, the presence of metastatic disease, and being diagnosed with hepatocellular carcinoma were found to be associated with mortality.

CONCLUSIONS

The incidence of hepatic cancer in children appears to have increased over the last 30 years in Australia and North America. Survival differences between Australia; Ontario, Canada; and the United States observed in the 1980s and 1990s were no longer apparent and only marginal geographical differences in the hazard of mortality were observed.

Pediatric Hepatoblastoma: What the Sonographer Needs to Know for the Sonographic Evaluation of Complications After Treatment and After Liver Transplantation

Hepatoblastoma (HB) is a common primary pediatric liver tumor, and its typical presentation is a palpable, nontender abdominal mass that is detected through sonographic imaging. The current treatment standard for HB includes chemotherapy followed by liver resection or transplantation. Throughout the management of HB, high-quality sonographic images inform diagnosis, treatment interventions, and detection of surgical treatment complications. It is important that sonographers be familiar with the presentation and complications of HB on imaging examinations. The authors review sonographic detection, evaluation of HB at presentation, and common complications after liver resection and transplantation.

Childhood liver tumors in Argentina: Incidence trend and survival by treatment center. A report from the national pediatric cancer registry, ROHA network 2000-2015

BACKGROUND

Information on the epidemiology of pediatric liver tumors in Latin America is limited.

PURPOSE

To describe the incidence of liver tumors in a pediatric registry in Argentina according to geographic region, national trends over 16 years, and survival related to stage, age, sex, and care center.

METHODS

Newly diagnosed liver tumors cases are registered in the Argentine Pediatric Oncology Hospital Registry (ROHA) with an estimated coverage of 91% of national cases. Age-standardized incidence rate per millon (ASR) was calculated based on the National Vital Statistics Reports. Five-year overall survival (OS) was estimated using the Kaplan-Meier method. The log-rank test was used to compare subgroup survival.

RESULTS

Two hundred seven cases of hepatoblastoma (HB) and 73 of hepatocellular carcinoma (HCC) were identified. ASR of liver tumors was 1.8/million (95% confidence Interval [CI], 1.6-2.0) per year. ASR was 1.4 (1.2-1.6) for HB and 0.4 (0.3-0.5) for HCC. For HB, the highest incidence was found in the northwest region including the Altiplano. OS was 60.4% (53.4-66.8) for HB and 36.1% (25.2-47.2) for HCC. Five-year survival rate of children with metastatic HB treated at liver transplant hospitals (LTH) was 54.2% (30.3-73.0) compared to 13.3% (2.2-34.6) for those seen at other hospitals (OH) (P = .02), while for HCC this rate was 46.3% (30.7-60.6) at LTH compared to 17.5% (3.1-41.9) at OH (P = .01).

CONCLUSIONS

The incidence rate of pediatric liver tumors was stable over the 16-year study period. Patients may benefit if at treatment initiation they are evaluated jointly with LTH specialists to define treatment strategies.

The importance of age as prognostic factor for the outcome of patients with hepatoblastoma: Analysis from the Children's Hepatic tumors International Collaboration (CHIC) database

PURPOSE

Treatment outcomes for hepatoblastoma have improved markedly in the contemporary treatment era, principally due to therapy intensification, with overall survival increasing from 35% in the 1970s to 90% at present. Unfortunately, these advancements are accompanied by an increased incidence of toxicities. A detailed analysis of age as a prognostic factor may support individualized risk-based therapy stratification.

METHODS

We evaluated 1605 patients with hepatoblastoma included in the CHIC database to assess the relationship between event-free survival (EFS) and age at diagnosis. Further analysis included the age distribution of additional risk factors and the interaction of age with other known prognostic factors.

RESULTS

Risk for an event increases progressively with increasing age at diagnosis. This pattern could not be attributed to the differential distribution of other known risk factors across age. Newborns and infants are not at increased risk of treatment failure. The interaction between age and other adverse risk factors demonstrates an attenuation of prognostic relevance with increasing age in the following categories: metastatic disease, AFP < 100 ng/mL, and tumor rupture.

CONCLUSION

Risk for an event increased with advancing age at diagnosis. Increased age attenuates the prognostic influence of metastatic disease, low AFP, and tumor rupture. Age could be used to modify recommended chemotherapy intensity.