Management of liver tumors in childhood

Computed tomography imaging phenotypes of hepatoblastoma identified from radiomics signatures are associated with the efficacy of neoadjuvant chemotherapy

BACKGROUND

Though neoadjuvant chemotherapy has been widely used in the treatment of hepatoblastoma, there still lacks an effective way to predict its effect.

OBJECTIVE

To characterize hepatoblastoma based on radiomics image features and identify radiomics-based lesion phenotypes by unsupervised machine learning, intended to build a classifier to predict the response to neoadjuvant chemotherapy.

MATERIALS AND METHODS

In this retrospective study, we segmented the arterial phase images of 137 cases of pediatric hepatoblastoma and extracted the radiomics features using PyRadiomics. Then unsupervised k-means clustering was applied to cluster the tumors, whose result was verified by t-distributed stochastic neighbor embedding (t-SNE). The least absolute shrinkage and selection operator (LASSO) regression was used for feature selection, and the clusters were visually analyzed by radiologists. The correlations between the clusters, clinical and pathological parameters, and qualitative radiological features were analyzed.

RESULTS

Hepatoblastoma was clustered into three phenotypes (homogenous type, heterogenous type, and nodulated type) based on radiomics features. The clustering results had a high correlation with response to neoadjuvant chemotherapy (P=0.02). The epithelial ratio and cystic components in radiological features were also associated with the clusters (P=0.029 and 0.008, respectively).

CONCLUSIONS

This radiomics-based cluster system may have the potential to facilitate the precise treatment of hepatoblastoma. In addition, this study further demonstrated the feasibility of using unsupervised machine learning in a disease without a proper imaging classification system.

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

Malignant focal liver lesions (FLLs) represent various kinds of epithelial and mesenchymal tumors. In pediatric patients, the understanding of pediatric liver diseases and associated imaging manifestations is essential for making accurate diagnosis and differential diagnosis. This paper will discuss the latest knowledge of the common pediatric malignant FLLs, including undifferentiated embryonal sarcoma, rhabdomyosarcoma, epithelioid hemangioendothelioma, angiosarcoma, and malignant rhabdoid tumor. Medical imaging features are not only helpful for clinical diagnosis, but can also be useful in the evaluation and follow-up of pre- and post-treatment. The future perspectives of contrast-enhanced ultrasound (CEUS) enhancement patterns of FLLs in pediatric patients are also mentioned.

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.

Comparison of transection techniques in pediatric major hepatectomy: a matched pair analysis

BACKGROUND

Evidence on safety and efficacy of different liver transection techniques in pediatric major hepatectomy is completely lacking, as no study has been conducted so far. The use of stapler hepatectomy has never before been reported in children.

METHODS

Three liver transection techniques were compared: (1) ultrasonic dissector (CUSA), (2) tissue sealing device (LigaSure™), and (3) stapler hepatectomy. All pediatric hepatectomies performed at a referral center in a 12-year study period were analyzed, patients were pair-matched in a 1:1:1-fashion. Intraoperative weight-adjusted blood loss, operation time, use of inflow occlusion, liver injury (peak-transaminase levels), postoperative complications (CCI), and long-term outcome were compared.

RESULTS

Of 57 pediatric liver resections, 15 patients were matched as triples based on age, weight, tumor stage, and extent of resection. Intraoperative blood loss was not significantly different between the groups (p = 0.765). Stapler hepatectomy was associated with significantly shorter operation time (p = 0.028). Neither postoperative death nor bile leakage occurred, and no reoperation due to hemorrhage was needed in any patient.

CONCLUSION

This is the first comparison of transection techniques in pediatric liver resection and the first report on stapler hepatectomy in children. All three techniques can be safely applied and may harbor individual advantages in pediatric hepatectomy each.

SNORA14A inhibits hepatoblastoma cell proliferation by regulating SDHB-mediated succinate metabolism

Hepatoblastoma (HB) is the most common paediatric liver malignancy. Dysregulation of small nucleolar RNAs (snoRNAs) is a critical inducer of tumour initiation and progression. However, the association between snoRNAs and HB remains unknown. Here, we conducted snoRNA expression profiling in HB by snoRNA sequencing and identified a decreased level of SNORA14A, a box H/ACA snoRNA, in HB tissues. Low expression of SNORA14A was correlated with PRETEXT stage and metastasis in patients. Functionally, overexpression of SNORA14A suppressed HB cell proliferation and triggered cell apoptosis and G2/M phase arrest. Mechanistically, SNORA14A overexpression promoted the processing and maturation of the 18 S ribosomal RNA (rRNA) precursor to increase succinate dehydrogenase subunit B (SDHB) protein levels. In accordance with SNORA14A downregulation, SDHB protein expression was significantly reduced in HB tissues and cells, accompanied by abnormal accumulation of succinate. Overexpression of SDHB showed antiproliferative and proapoptotic effects and the capacity to induce G2/M phase arrest, while succinate dose-dependently stimulated HB cell growth. Furthermore, the inhibition of SNORA14A in HB malignant phenotypes was mediated by SDHB upregulation-induced reduction of cellular succinate levels. Therefore, the SNORA14A/18 S rRNA/SDHB axis suppresses HB progression by preventing cellular accumulation of the oncometabolite succinate and provides promising prognostic biomarkers and novel therapeutic targets for HB.

Neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio as predictive markers in hepatoblastoma

Background

The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been presented to be a prognostic indicator in several cancers. We were supposed to evaluate the prognostic role of such inflammatory markers in hepatoblastoma (HB).

Methods

Total of 101 children, diagnosed with hepatoblastoma between January 2010 and January 2018, were enrolled before treatment in the study. The clinicopathological parameters, and outcomes were collected through laboratory analyses and patient follow-up. The association between NLR, PLR, and clinicopathological characters were analyzed with Wilcoxon test, Chi-Squared test, Kaplan-Meier, Log-rank and Cox regression analyses.

Results

NLR and PLR were significantly elevated in HB patients (P < 0.001), and related to age (P < 0.001), risk stratification system (P < 0.001), and pretreatment extent of disease (P < 0.0001). NLR was significantly related to alpha-fetoprotein (P = 0.034) and lactate dehydrogenase (P = 0.026). The 3-year overall survival (OS) and event-free survival (EFS) were poor in the high-NLR group (OS: 44.3% vs. 90.3%, P < 0.0001, EFS: 38.6% vs. 80.6%, P = 0.0001). The 3-year OS and EFS were poor in the high-PLR group (OS: 49.1% vs. 68.8%, P = 0.016, EFS: 39.6% vs. 64.6%, P = 0.0117). The multivariate analysis suggested that NLR (HR: 11.359, 95% CI: 1.218-105.947; P = 0.033) and risk stratification (HR: 44.905, 95% CI: 2.458-820.36; P = 0.01), were independent predictors of OS.

Conclusion

Our research showed that elevated NLR and PLR were the poor prognostic factors in HB patients before treatment. The NLR was an independent prognostic factor for OS.

The Cellular and Molecular Landscape of Synchronous Pediatric Sialoblastoma and Hepatoblastoma

Sialoblastoma (SBL) is an infrequent embryonal malignant tumor originating from the salivary gland, resembling primitive salivary gland anlage, whereas hepatoblastoma (HB) is the most common pediatric liver malignancy. The simultaneous occurrence of both tumors is extremely rare. Here we reported a case of a 6-month-old infant diagnosed with synchronous SBL and HB. The patient received neoadjuvant chemotherapy followed by surgical resection. Fresh tissues of both tumors were collected before and after chemotherapy, which were further profiled by whole exome sequencing (WES) and single-cell RNA sequencing (scRNA-seq). WES analysis revealed potential somatic driver mutation PIK3CA p.Glu454Lys for SBL and canonical mutation CTNNB1 p.Ser45Pro for HB. No shared somatic variants or common copy number alterations were found between SBL and HB primary tumor samples. Though scRNA-seq, single-cell atlases were constructed for both tumors. SBL may recapitulate a pre-acinar stage in the development of salivary gland, including basaloid, duct-like, myoepithelial-like, and cycling phenotypes. In the meantime, HB was composed of tumor cells resembling different stages of the liver, including hepatocyte-like, hepatic progenitor-like, and hepatoblast-like cells. After chemotherapy, both tumors were induced into a more mature phenotype. In terms of transcriptional signatures, SBL and HB showed enhanced expression of epithelial markers KRT8, KRT18, and essential embryo development genes SDC1, MDK, indicating the disruption of normal embryo epithelium development. Finally, heterozygous deleterious germline mutation BLM and FANCI were identified which could predispose the patient to higher cancer risk. It partially explained the reason for the co-occurrence of SBL and HB. Taken together, we provided valuable resources for deciphering cellular heterogeneity and adaptive change of tumor cells after chemotherapy for synchronous SBL and HB, providing insights into the mechanisms leading to synchronous pediatric tumors.

Mitochondrial fragmentation is crucial for c-Myc-driven hepatoblastoma-like liver tumor

Hepatoblastoma is the most common liver cancer in children, and the aggressive subtype often has a poor prognosis and lacks effective targeted therapy. Although aggressive hepatoblastoma (HB) is often accompanied by abnormally high expression of the transcription factor c-Myc, the underlying mechanism remains unclear. In this study, we found that mitochondrial fragmentation was enhanced by c-Myc overexpression in human aggressive HB tissues and was associated with poor prognosis. Then, a mouse model resembling human HB was established via hydrodynamic injection of c-Myc plasmids. We observed that liver-specific knockout of the mitochondrial fusion molecule MFN1 or overexpression of mitochondrial fission molecule DRP1 promoted the occurrence of c-Myc-driven liver cancer. In contrast, when MFN1 was overexpressed in the liver, tumor formation was delayed. In vitro experiments showed that c-Myc transcriptionally upregulated the expression of DRP1 and decreased MFN1 expression through upregulation of miR-373-3p. Moreover, enhanced mitochondrial fragmentation significantly promoted aerobic glycolysis and the proliferation of HB cells by significantly increasing reactive oxygen species (ROS) production and activating the RAC-alpha serine/threonine-protein kinase (AKT)/mammalian target of rapamycin (mTOR) and nuclear factor κB (NF-κB) pathways. Taken together, our results indicate that c-Myc-mediated mitochondrial fragmentation promotes the malignant transformation and progression of HB by activating ROS-mediated multi-oncogenic signaling.

Liver tumors in children with chronic liver diseases

Liver tumors are rare in children, but the incidence may increase in some circumstances and particularly in chronic liver diseases. Most liver tumors consequent to chronic liver diseases are malignant hepatocellular carcinoma. Other liver tumors include hepatoblastoma, focal nodular hyperplasia, adenoma, pseudotumor, and nodular regenerative hyperplasia. Screening of suspected cases is beneficial. Imaging and surrogate markers of alpha-fetoprotein are used initially as noninvasive tools for surveillance. However, liver biopsy for histopathology evaluation might be necessary for patients with inconclusive findings. Once the malignant liver tumor is detected in children with cirrhosis, liver transplantation is currently considered the preferred option and achieves favorable outcomes. Based on the current evidence, this review focuses on liver tumors with underlying chronic liver disease, their epidemiology, pathogenesis, early recognition, and effective management.

Risk Factors for 30-Day Unplanned Readmission After Hepatectomy: Analysis of 438 Pediatric Patients from the ACS-NSQIP-P Database

BACKGROUND

Hepatic resections are uncommon in children. Most studies reporting complications of these procedures and risk factors associated with unplanned readmissions are limited to retrospective data from single centers. We investigated risk factors for 30-day unplanned readmission after hepatectomy in children using the American College of Surgeons National Surgical Quality Improvement-Pediatric database.

METHODS

The database was queried for patients aged 0-18 years who underwent hepatectomy for the treatment of liver lesions from 2012 to 2018. Chi-squared tests were performed to evaluate for potential risk factors for unplanned readmissions. A multivariate regression analysis was performed to identify independent predictors for unplanned 30-day readmissions.

RESULTS

Among 438 children undergoing hepatectomy, 64 (14.6%) had unplanned readmissions. The median age of the hepatectomy cohort was 1 year (0-17); 55.5% were male. Patients readmitted had significantly higher rates of esophageal/gastric/intestinal disease (26.56% vs. 14.97%; p=0.022), current cancer (85.94% vs. 75.67%; p=0.012), and enteral and parenteral nutritional support (31.25% vs. 17.65%; p=0.011). Readmitted patients had significantly higher rates of perioperative blood transfusion (67.19% vs. 52.41%; p=0.028), organ/space surgical site infection (10.94% vs. 1.07%; p<.001), sepsis (15.63% vs. 3.74%; p<.001), and total parenteral nutrition at discharge (9.09% vs. 2.66%; p=0.041). Organ/space surgical site infection was an independent risk factor for unplanned readmission (OR=9.598, CI [2.070-44.513], p=0.004) by multivariable analysis.

CONCLUSION

Unplanned readmissions after liver resection are frequent in pediatric patients. Organ/space surgical site infections may identify patients at increased risk for unplanned readmission. Strategies to reduce these complications may decrease morbidity and costs associated with unplanned readmissions.

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.

Stereotactic radiofrequency ablation of a variety of liver masses in children

BACKGROUND AND AIMS

Surgical resection is currently the cornerstone of liver tumor treatment in children. In adults radiofrequency ablation (RFA) is an established minimally invasive treatment option for small focal liver tumors. Multiprobe stereotactic RFA (SRFA) with intraoperative image fusion to confirm ablation margins allows treatment for large lesions. We describe our experience with SRFA in children with liver masses.

METHODS

SRFA was performed in 10 patients with a median age of 14 years (range 0.5-17.0 years) suffering from liver adenoma (n = 3), hepatocellular carcinoma (n = 1), hepatoblastoma (n = 2), myofibroblastic tumor (n = 1), hepatic metastases of extrahepatic tumors (n = 2) and infiltrative hepatic cysts associated with alveolar echinococcosis (n = 1). Overall, 15 lesions with a mean lesion size of 2.6 cm (range 0.7-9.5 cm) were treated in 11 sessions.

RESULTS

The technical success rate was 100%, as was the survival rate. No transient adverse effects higher than grade II (Clavien and Dindo) were encountered after interventions. The median hospital stay was 5 d (range 2-33 d). In two patients who subsequently underwent transplant hepatectomy complete ablation was histologically confirmed. Follow-up imaging studies (median 55 months, range 18-129 months) revealed no local or distant recurrence of disease in any patient.

CONCLUSIONS

SRFA is an effective minimal-invasive treatment option in pediatric patients with liver tumors of different etiologies.

Experience of treating pediatric hepatoblastoma at King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia - Timely surgical intervention playing a key role

BACKGROUND

Many studies have demonstrated that outcome in patients with hepatoblastoma is determined by tumor resectability and the presence or absence of metastatic disease.

PURPOSE

To evaluate and disseminate information on diagnosis, treatment, and outcome of hepatoblastoma patients at a tertiary care hospital in Saudi Arabia.

PATIENTS AND METHODS

Twenty-four pediatric patients with hepatoblastoma were treated at our institution between January 2005 and December 2012. The majority of our patients were stage III and above, while one-third of them presented with metastatic disease. Four (16.7%) had vascular invasion. Two-thirds of our patients (n = 16, 66.7%) had alpha-fetoprotein (AFP) level above 100,000 ng/mL. Twenty-one patients underwent surgery; two had upfront surgery before getting any chemotherapy, and 15 had surgery on schedule after pre-operative chemotherapy. Four patients had delayed surgery as the tumor was not resectable and received extra cycles of chemotherapy. Chemotherapy regimens used were based on SIOPEL study protocols until 2011 and Children's Oncology Group (COG) protocol from 2012 onwards. Relapse, progressive disease, or death from any cause were defined as events.

RESULTS

Five-year overall survival (OS) of the cohort over a median follow-up time of 56.1 months was 70.6% ± 9.4% with seven (29.2%) events of mortality. No significant difference was found for age at diagnosis (less than 2 years vs. more), stage of disease, AFP levels (less than 100,000 vs. more), vascular invasion, or presence of metastatic disease at presentation in terms of OS. However, children receiving upfront or scheduled as-per-protocol surgery fared better than those who had delayed surgery (as the tumor was not resectable and they received extra cycles of chemotherapy) or did not undergo any surgery (P-Value .001).

CONCLUSION

Favorable survival outcome could be achieved with complete tumor excision and adjuvant chemotherapy. Inability to perform surgical excision was the single most important predictor of mortality in our patients.

Infantile hepatic hemangioma: current state of the art, controversies, and perspectives

Infantile hepatic hemangioma (IHH) is a common vascular tumor, distinctive for its perinatal presentation, rapid growth during the first year of life, and subsequent involution. Although they generally follow a benign course, some tumors have been reported to undergo malignant transformation. The diagnosis of IHH is based on patient's medical history, physical examination, and imaging. Moreover, the management of this vascular tumor is based on clinical presentation and includes observational, medical, surgical, and radiological interventional treatment options. The present review presents the currently available data in the literature on the diverse aspects of the terminology, epidemiology, clinical presentation, pathogenesis, diagnosis, indications for surgery, malignant potential, and long-term outcomes of these tumors.Conclusion: No formal guidelines have yet been established for the treatment of these hepatic lesions, and the therapeutic strategies implemented vary widely from simple observation to medical, radiological, and surgical interventions in the prism of multidisciplinary teams.What is Known:• Infantile hepatic hemangioma is the most common benign tumor of the liver in infancy, but despite its benign nature, it can present with life-threatening complications.• The treatment strategies range from simple observation to a series of medical, surgical, and radiological interventions.What is New:• This review gives an overview of the developments and current status about the management of IHH.• The aim of this study is to clear up the confusion and controversy that exists about terminology, diagnosis, and treatment of IHH.

Neurokinin-1 Receptor Antagonists as Anticancer Drugs

Background::

Human tumor cells lines and tumor samples overexpress the neurokinin-1 receptor (NK-1R). Substance P (SP), after binding to NK-1Rs, induces tumor cell proliferation, an antiapoptotic effect and promotes angiogenesis and the migration of cancer cells for invasion and metastasis.

Methods: :

In contrast, NK-1R antagonists block the previous pathophysiological actions mediated by SP. These antagonists promote the death of tumor cells by apoptosis. Peptide and non-peptide NK-1R antagonists have been reported.

Results: :

Peptide NK-1R antagonists show chemical modifications of the SP molecule (L-amino acids being replaced by D-amino acids), whereas non-peptide NK-1R antagonists include numerous compounds with different chemical compositions while showing similar stereochemical features (affinity for the NK- 1R). Currently, there are more than 300 NK-1R antagonists.

Conclusion::

In combination therapy with classic cytostatics, NK-1R antagonists have additive or synergic effects and minimize the side-effects of cytostatics. The effect of NK-1R antagonists as broad-spectrum anticancer drugs is reviewed and the use of these antagonists for the treatment of cancer is suggested.

CircHMGCS1 Promotes Hepatoblastoma Cell Proliferation by Regulating the IGF Signaling Pathway and Glutaminolysis

Circular RNAs (circRNAs), a novel class of endogenous RNAs, have been recently shown to participate in cellular development and several pathophysiological processes. The identification of dysregulated circRNAs and their function in cancer have attracted considerable attention. Nevertheless, the expression profile and role of circRNAs in human hepatoblastoma (HB) remain to be studied. In this report, we analyzed the expression prolife of circRNAs in HB tissues and identified circHMGCS1 (3-hydroxy-3-methylglutaryl-CoA synthase 1; hsa_circ_0072391) as a remarkably upregulated circRNA. Methods: The expression prolife of circRNAs in HB tissues were investigated through circRNA sequencing analyses. ISH and qRT-PCR assays were performed to measure the expression level of circHMGCS1. The effect of knocking down circHMGCS1 in HB cells in vitro and in vivo were evaluated by colony formation assay, flow cytometry, xenograft tumors assay and untargeted metabolomics assay. MRE analysis and dual luciferase assay were performed to explore the underlying molecular mechanisms. Results: HB patients with high circHMGCS1 expression have shorted overall survival. Knockdown of circHMGCS1 inhibits HB cells proliferation and induces apoptosis. CircHMGCS1 regulates IGF2 and IGF1R expression via sponging miR-503-5p, and affects the downstream PI3K-Akt signaling pathway to regulate HB cell proliferation and glutaminolysis. Conclusions: The circHMGCS1/miR-503-5p/IGF-PI3K-Akt axis regulates the proliferation, apoptosis and glutaminolysis of HB cells, implying that circHMGCS1 is a promising therapeutic target and prognostic marker for HB patients.

Pediatric Liver Tumors

Although liver tumors are rare in the pediatric population, they are common in the setting of children with specific risk factors requiring increased awareness and, in some instances, screening. The evaluation of a liver mass in children is largely driven by the age at diagnosis, the presence of any medical comorbidities, and initial testing with alpha fetoprotein and imaging. Specific guidelines for the management of different tumors have been implemented in recent years such that a multidisciplinary approach is ideal and care should be provided by centers with experience in their management.

Targeting LRH‑1 in hepatoblastoma cell lines causes decreased proliferation

Hepatoblastoma is the most common malignant liver tumor in children. Since it is often unresectable and exhibits drug resistance, the treatment of advanced hepatoblastoma is challenging. The orphan nuclear receptor liver receptor homolog-1 (LRH-1) serves prominent roles in malignancy; however, to the best of our knowledge, the role of LRH-1 in hepatoblastoma remains unknown. In the present study, human hepatoblastoma cell lines were analyzed; the mRNA and protein expression levels of LRH-1 were significantly higher in HepG2 and HuH6 cells compared with those in HepT1 cells and control THLE-2 cells. Knockdown of LRH-1 resulted in decreased HepG2 and HuH6 cell proliferation via downregulation of cyclin D1 (CCND1) and c-Myc. Furthermore, treatment with an LRH-1 antagonist (LRA) inhibited the proliferation and colony formation of cell lines in a dose-dependent manner, and induced cell cycle arrest at G₁ phase through inhibition of CCND1 expression. Finally, LRA treatment enhanced the cytotoxic effects of doxorubicin on hepatoblastoma cells. Collectively, these findings suggested that LRH-1 may have an important role in the progression of hepatoblastoma and implicated LRA as a novel, potential therapeutic agent for the treatment of hepatoblastoma.

Magnetic resonance imaging features of common focal liver lesions in children

Magnetic resonance imaging (MRI) is commonly used to characterize focal liver masses in the pediatric population. MRI is the preferred modality because of its superior contrast resolution and utility for obtaining functional sequences such as diffusion-weighted imaging (DWI). MR exams performed with a hepatocyte-specific gadolinium-based contrast agent can characterize focal liver lesions, which helps in differentiating a common benign entity such as focal nodular hyperplasia from other liver pathology when the background liver is normal. The most common benign focal lesion is a hemangioma, and metastases followed by hepatoblastoma are the most common malignant lesions. This article can help radiologists become familiar with the pre- and post-contrast imaging features of common pediatric liver masses.

20(S)-Protopanaxadiol induces apoptosis in human hepatoblastoma HepG2 cells by downregulating the protein kinase B signaling pathway

Hepatoblastoma is the most common primary liver tumor for children aged <5 years old. 20(S)-Protopanaxadiol (PPD) is a ginsenoside extracted from Pananx quinquefolium L., which inhibits tumor growth in several cancer cell lines. The purpose of the present study was to assess the anticancer activities of 20(S)-PPD in human hepatoblastoma HepG2 cells. The cytotoxicity of 20(S)-PPD on HepG2 cells was evaluated using an MTT assay. Apoptosis was detected using DAPI staining and flow cytometry. The expression of apoptosis-associated proteins was identified by western blotting. The results demonstrated that 20(S)-PPD inhibited the viability of HepG2 cell in a dose and time-dependent manner. The IC₅₀ values were 81.35, 73.5, 48.79 µM at 24, 48 and 72 h, respectively. Topical morphological changes of apoptotic body formation following 20(S)-PPD treatment were detected by DAPI staining. The percentage of Annexin V-fluoroscein isothyiocyanate positive cells were 3.73, 17.61, 23.44 and 65.43% in HepG2 cells treated with 0, 40, 50 and 60 µM of 20(S)-PPD, respectively. Furthermore, 20(S)-PPD upregulated the expression of Bax and downregulated the expression of Bcl-2 and also activated caspases-3 and −9, and Poly [ADP-ribose] polymerase cleavage. In addition, 20(S)-PPD inhibited the phosphorylation of protein kinase B (Akt; Ser473). The results indicate that 20(S)-PPD inhibits the viability of HepG2 cells and induces apoptosis in HepG2 cells by inhibiting the phosphoinositide-3-kinase/Akt pathway.

Low dosage of arsenic trioxide inhibits vasculogenic mimicry in hepatoblastoma without cell apoptosis

Hepatoblastoma (HB) is the most common type of pediatric liver malignancy, which predominantly occurs in young children (aged <5 years), and continues to be a therapeutic challenge in terms of metastasis and drug resistance. As a new pattern of tumor blood supply, vasculogenic mimicry (VM) is a channel structure lined by tumor cells rather than endothelial cells, which contribute to angiogenesis. VM occurs in a variety of solid tumor types, including liver cancer, such as hepatocellular carcinoma. The aim of the present study was to elucidate the effect of arsenic trioxide (As₂O₃) on VM. In vitro experiments identified that HB cell line HepG₂ cells form typical VM structures on Matrigel, and the structures were markedly damaged by As₂O₃ at a low concentration before the cell viability significantly decreased. The western blot results indicated that As₂O₃ downregulated the expression level of VM-associated proteins prior to the appearance of apoptotic proteins. In vivo, VM has been observed in xenografts of HB mouse models and identified by periodic acid-Schiff⁺/CD105⁻ channels lined by HepG₂ cells without necrotic cells. As₂O₃ (2 mg/kg) markedly depresses tumor growth without causing serious adverse reactions by decreasing the number of VM channels via inhibiting the expression level of VM-associated proteins. Thus, the present data strongly indicate that low dosage As₂O₃ reduces the formation of VM in HB cell line HepG₂ cells, independent of cell apoptosis in vivo and in vitro, and may represent as a candidate drug for HB targeting VM.

Management of Hepatoblastoma: ICMR Consensus Document

Dramatic advancement has been made in the management of children with hepatoblastoma (HB) over the past 3 decades owing to the improvement in diagnostic imaging, new chemotherapeutic agents, better surgical care and availability of liver transplantation. These advances are the end results of contributions from 4 major study groups across the globe including International Society of Pediatric Oncology - Liver Tumor Strategy Group (SIOPEL), Children's Oncology Group (COG), German Pediatric Hematology Oncology Group (GPOH) and Japanese Pediatric Liver Tumor Study Group (JPLT). The current manuscript is written with the objective of developing a consensus guideline for practitioners at a National level. Based on literature and personal experience over last 3 decades, the Indian Council of Medical Research (ICMR) Expert group has made recommendations for management of children with HB in resource-challenged nations including India.

Hepatocellular Carcinoma in Children and Adolescents: Clinical Characteristics and Treatment

BACKGROUND

Hepatocellular carcinoma (HCC) occurs rarely in children and adolescents (C&A), and its clinical characteristics, prognostic factors, and treatment were rarely explored.

METHODS

This retrospective study focused on 65 HCC patients aged ≤20 years from August 1994 to August 2012. Cox regression models and Kaplan-Meier curves were used to investigate prognostic factors and compare overall survival (OS), respectively.

RESULTS

We found 61.5% of patients to have multiple tumors, 30.8% to have portal vein tumor thrombus, and 16.9% to have distant metastasis. Diameter of tumors was 10.2 ± 4.1 cm. OS at 5 years was 15.8%. Multivariate analyses showed initial treatment (P < 0.001) to be a predictor for OS. For moderate-stage HCC, the median OS of patients who underwent resection was longer than that of patients who underwent transarterial chemoembolization (TACE) or supportive treatment (ST) (P < 0.001). For advanced-stage HCC, the median OS of patients who underwent TACE was longer than that of patients who underwent ST (P = 0.045).

CONCLUSIONS

HCC in C&A tends to be more advanced than that in adults, and resection remains the mainstay of treatment for those patients. Moreover, compared with ST, TACE may benefit C&A with moderate- and advanced-stage HCC, which needs further study.

Space Occupying Lesions in the Liver

Space occupying liver lesions usually present with abdominal pain or abnormal physical findings, such as a palpable abdominal mass or distention. Liver lesions identified in children include benign and malignant neoplasms, inflammatory masses, cysts and metastatic lesions. Two-thirds of liver lesions in children are malignant. Hepatoblastoma accounts for two-thirds of malignant liver tumors in children. Benign lesions of the liver in children include vascular lesions, hamartomas, adenomas, and focal nodular hyperplasia. Although benign and malignant liver masses share some clinical manifestations, however treatment and prognosis differ. Evaluation involves physical examination, imaging evaluation and laboratory investigations such as serological markers [alpha-fetoprotein (AFP)] for malignant liver lesions. Ultrasound is the initial imaging modality of choice because it can detect, characterize, and provide the extent of liver lesions. However, CT or MRI are often subsequently performed for further characterization, assessment of precise extent, and detection of associated metastatic disease in cases of malignant hepatic neoplasm. Serological markers (such as alpha fetoprotein) can be useful in narrowing the differential diagnosis when they are markedly elevated but a substantial number of patients unfortunately do not have high levels of these markers at the time of presentation or cautious interpretation is warranted as AFP level is frequently elevated in infants up to 6 mo of age and may be slightly elevated with benign tumors and with hepatic insult or regeneration. Therefore, a tissue diagnosis is often required to guide subsequent management. The histology and anatomy of a pediatric liver tumor guides the treatment and prognosis.

Huge focal nodular hyperplasia presenting in a 6-year-old child: A case presentation

•

FNH is a benign lesion of the liver which is rare in children.

•

We report the case of a 6-year-old child (male) with a huge FNH which size is more than 10 cm. This could be the biggest FNH among all children’s FNH cases ever reported.

•

When pediatric FNH patients accord with (1) clinical symptoms; (2) indefinite diagnosis or hepatitis B virus carriage; (3) tumor size >5 cm, surgical treatment could be considered.

Introduction

Focal nodular hyperplasia (FNH) is a benign lesion of the liver which is usually found in healthy adults, however, FNH is rare in children, and comprises only 2% of all pediatric liver tumors. Herein, we report the case of a 6-year-old child (male) with a huge FNH which size is more than 10 cm. This could be the biggest FNH among all children’s FNH cases ever reported.

Case presentation

A 6-year-old boy was found a hepatic space-occupying lesion two years ago. As the time went by, the lesion became bigger gradually. The last CT examination showed the size of the tumor to be 10.5 × 9.9 cm in the right hepatic lobe. This child underwent surgical resection of the tumor which was confirmed as FNH (11 × 8 × 7 cm) by pathology.

Conclusion

FNH is a benign lesion of the liver, and it is characterized by hepatocyte hyperplasia and a central stellate scar. It is uncommon for FNH to be diagnosed in children. Such huge FNH (about 11 cm) is extremely rare. Surgical operation may be the effective method to cure huge FNH.

A single-center retrospective study of pediatric hepatoblastoma

Hepatoblastoma is a malignant liver tumor generally diagnosed in infants and children <3 years old. The current retrospective study aimed to investigate the associations of tumor stage, pathological type, metastasis and chemotherapy with clinical outcomes. In the current study, a total of 102 patients with hepatoblastoma were enrolled between September 2006 and June 2014. Clinical records and follow-up information for each of patient were obtained to conduct a Kaplan-Meier survival analysis and log-rank test. The median age of the subjects was 1.5 years, and 98 patients had stage III or IV hepatoblastoma. Complete or partial remittance occurred in 72 subjects, and 91 underwent surgical operation. The survival rate differed significantly among patients with different tumor stages (P=0.015, χ²=8.359). The mortality rate of stage IV subjects with intrahepatic metastasis was significantly higher than that of those without (P=0.004). Among the 45 subjects with relapsed hepatoblastoma, the mortality rate was higher in the subjects that abandoned chemotherapy than in patients who continued regular chemotherapy. In total, 27 of 45 subjects with relapsed hepatoblastoma succumbed to the disease; 20 of them abandoned chemotherapy treatment; and the remaining 7 patients underwent regular chemotherapy and succumbed to the disease by the end of follow-up. The present study indicates that the increased mortality rate was associated with postoperative residual-induced intrahepatic metastasis and relapsed hepatoblastoma; and that regular chemotherapy is necessary for patient to achieve complete or partial remission following surgical operation.

Magnetic resonance imaging of primary pediatric liver tumors

Although primary hepatic neoplasms are less common than other intra-abdominal tumors in children, these neoplasms are a significant source of morbidity and mortality in the pediatric population. MRI is increasingly relied upon in the diagnostic evaluation of these lesions, both before and after treatment, and familiarity with the MRI findings associated with these neoplasms is a must for pediatric radiologists. Advances in MRI technology, particularly the advent of hepatocyte-specific gadolinium-based MRI contrast agents, have allowed for accurate characterization of several types of hepatic neoplasms on the basis of imaging appearance. In this review, we provide an overview of the approach to imaging hepatic neoplasms in children using MRI, including a sample imaging protocol. We also discuss the relevant clinical features and MRI findings of the most clinically relevant entities, including their appearance on post-contrast imaging using hepatocyte-specific gadolinium-based MRI contrast agents.

Multidisciplinary effort in treating children with hepatoblastoma in China

The purpose of this study is to report the first nationwide protocol (Wuhan Protocol) developed by Chinese Children's Cancer Group and the results of multidisciplinary effort in treating hepatoblastoma. In this study, we reported the final analysis, which includes 153 hepatoblastoma patients in 13 hospitals from January 2006 to December 2013. The 6-year overall survival and event-free survival rates were 83.3 ± 3.1% and 71.0 ± 3.7%, respectively, in this cohort. The univariate analysis revealed that female (P = 0.027), under 5 years of age (P = 0.039), complete surgical resection (P = 0.000), no metastases (P = 0.000), and delayed surgery following neoadjuvant chemotherapy (P = 0.000) had better prognosis. In multivariate analysis, male, 5 years of age or above, stage PRETEXT III or IV, and incomplete surgical resection were among the some adverse factors contributing to poor prognosis. The preliminary results from this study showed that patients who underwent treatment following Wuhan Protocol had similar OS and EFS rates compared to those in developed countries. However, the protocol remains to be further optimized in standardizing surgical resection (including liver transplantation), refining risk stratification and risk-based chemotherapy.

An infant with a diagnostically challenging hepatic teratoma, hypofibrinogenemia, and adrenal neuroblastoma: case report

Teratomas of the liver are exceedingly rare. Neuroblastoma is the most common, extracranial solid tumor of infancy. We describe the case of a 2-month-old, female infant who presented with an abdominal mass arising in the right lobe of the liver, and a severe coagulopathy, which necessitated cryoprecipitate infusion. Biopsy was interpreted as hepatoblastoma. Following resection, difficulty classifying the mass led to several consultations, and an eventual diagnosis of teratoma. During follow-up, the patient was diagnosed with right adrenal neuroblastoma, which, in retrospect, had been present before the hepatic resection. To our knowledge, these 2 tumors have never been reported together, or in combination with isolated hypofibrinogenemia.

The role of BH3-mimetic drugs in the treatment of pediatric hepatoblastoma

Pediatric hepatoblastoma (HB) is commonly treated by neoadjuvant chemotherapy and surgical tumor resection according to international multicenter trial protocols. Complete tumor resection is essential and survival rates up to 95% have now been achieved in those tumors classified as standard-risk HB. Drug resistance and occurrence of metastases remain the major challenges in the treatment of HB, especially in high-risk tumors. These conditions urgently require the development of alternative therapeutic strategies. One of those alternatives is the modulation of apoptosis in HB cells. HBs regularly overexpress anti-apoptotic proteins of the Bcl-family in comparison to healthy liver tissue. This fact may contribute to the development of chemoresistance of HB cells. Synthetic small inhibitory molecules with BH3-mimetic effects, such as ABT-737 and obatoclax, enhance the susceptibility of tumor cells to different cytotoxic drugs and thereby affect initiator proteins of the apoptosis cascade via the intrinsic pathway. Besides additive effects on HB cell viability when used in combination with cytotoxic drugs, BH3-mimetics also play a role in preventing metastasation by reducing adhesion and inhibiting cell migration abilities. Presumably, including additive BH3-mimetic drugs into existing therapeutic regimens in HB patients might allow dose reduction of established cytotoxic drugs and thereby associated immanent side effects, while maintaining the antitumor activity. Furthermore, reduction of tumor growth and inhibition of tumor cell dissemination may facilitate complete surgical tumor resection, which is mandatory in this tumor type resulting in improved survival rates in high-risk HB. Currently, there are phase I and phase II clinical trials in several cancer entities using this potential target. This paper reviews the available literature regarding the use of BH3-mimetic drugs as single agents or in combination with chemotherapy in various malignancies and focuses on results in HB cells.

Clinical efficacy and prognosis factors for advanced hepatoblastoma in children: a 6-year retrospective study

OBJECTIVE

This study aimed to investigate the effect of multimodality treatment of advanced paediatric hepatoblastoma (HB) and the factors affecting prognosis.

METHODS

A total of 35 children underwent multimodality treatments consisting of chemotherapy, surgery, interventional therapy, and autologous peripheral blood stem cell transplantation. The patients were followed up every month.

RESULTS

Serum AFP levels in 33 out of 35 patients in this study were significantly increased (P = 0.0002). According to the statistical scatter plot, the values of serum AFP on the 25th, 50th, and 75th percentages were 1,210, 1,210 and 28,318 ng/dl, respectively. Of the 35 cases, 21 were stage IV. 18 cases were treated with systemic chemotherapy before surgery, and 3 cases with locally interventional chemotherapy before surgery. Statistical analysis showed that the preferred interventional treatment affected prognosis, and that there was a statistically significant difference (P = 0.024). Some 33 patients completed the follow-up, of which 17 were in complete remission (CR), 5 were in partial remission (PR), 1 became disease progressive (DP) , and 10 died. The remission and overall survival rates were 66.7% (22/33) and 69.7% (23/33), respectively. Patients with the mixed HB phenotypes had worse prognoses than the epithelial phenotype (P < 0.001), and patients in stage IV had a lower survival rate than those in stage III (P < 0.001).

CONCLUSION

Multimodality treatment can effectively improve remission rate and prolong the survival of children with advanced HB. In addition, alpha-fetoprotein (AFP), a tumor marker of liver malignant tumors, HB pathological classification, and staging are highly useful in predicting prognosis.

Morbidity and mortality associated with liver resections for primary malignancies in children

PURPOSE

Liver resection (LR) is a high-risk procedure with limited data in the pediatric surgical literature regarding short-term outcomes. Our aim was to characterize the patient population and short-term outcomes for children undergoing LR for malignancy.

METHODS

We studied 126 inpatient admissions for children ≤20 years of age undergoing LR in 2009 using the Kids' Inpatient Database. Patients had a principal diagnosis of a primary hepatic malignancy and LR listed as one of the first five procedures. Transplantations were excluded. Complications were defined by ICD-9 codes. High-volume centers performed at least 5 LR.

RESULTS

The mean age was 5.83 years. The morbidity and mortality rates were 30.7 and 3.7%, respectively. The most common causes of morbidity were digestive system complications (7.4%), anemia (7.3%), and respiratory complications (3.8%). 43.9% received a blood product transfusion. The average length of stay was 10.04 days. When compared to low-volume centers, high-volume centers increased the likelihood of a complication fourfold (P = 0.011) but had 0% mortality (P = 0.089).

CONCLUSION

LR remains a procedure fraught with multiple complications and a significant mortality rate. High-volume centers have a fourfold increase in likelihood of complications compared to low-volume centers and may be related to extent of hepatic resection.

Yolk sac tumour: a rare cause of raised serum alpha-foetoprotein in a young child with a large liver mass

BACKGROUND

Primary yolk sac tumour of the liver is extremely rare, and when it occurs in a young child it can be confused with hepatoblastoma.

OBJECTIVE

To present a retrospective case series of primary hepatic yolk sac tumour from two institutions to highlight the imaging features.

MATERIALS AND METHODS

We conducted a retrospective review of pathological and imaging findings in biopsy-proven pure primary yolk sac tumour of the liver.

RESULTS

A total of three children (15 months to 6 years) presented between 2006 and 2012 with primary hepatic yolk sac tumour. Two children presented with acute abdomen after minor trauma caused by tumour rupture and haemoperitoneum. We identified five additional paediatric cases of pure hepatic yolk sac tumour with descriptions of imaging findings in the literature. In seven of these eight children, central necrosis was seen on cross-sectional imaging.

CONCLUSION

Primary yolk sac tumour should be considered as an alternative diagnosis to hepatoblastoma in a young child with a large liver mass and significantly raised serum alpha-foetoprotein, but in view of the nonspecific imaging features histological examination is essential for diagnosis. Although there are no specific imaging findings of primary yolk sac tumour, presence of cystic or necrotic areas and a tendency for tumour rupture are suggestive features.

Current therapeutic strategies for childhood hepatic tumors: surgical and interventional treatments for hepatoblastoma

Surgery is the mainstay of multimodal treatment for hepatoblastomas. Among the various staging systems used, PRETEXT is currently adopted in all major study groups worldwide as a common pretreatment staging system. Although variations of treatment strategies among study groups exist, the majority of hepatoblastoma cases currently undergo preoperative chemotherapy. It is therefore critical to determine the optimal surgical treatment during the initial courses of chemotherapy. Patients with PRETEXT IV tumors, multifocal tumors and tumors invading major vessels of the liver are candidates for liver transplantation. Liver transplantation requires preparation in advance, and consultation to a liver expertise team must take place no later than after two cycles of chemotherapy. The existence of pulmonary metastasis is a predictor of poor prognosis of the patient. Surgery for pulmonary nodules should be considered for those patients remaining positive after cycles of chemotherapy. A considerable number of patients have been reported to achieve long-term survival after resecting pulmonary metastasis. The existence of pulmonary metastasis at diagnosis is no longer a contraindication for liver transplantation, provided that the pulmonary nodules are eliminated by chemotherapy or by metastasectomy. Transcatheter arterial chemoembolization (TACE) is a useful tool for the local control of hepatoblastomas, although there are very few reports statistically supporting the significant advantage of this treatment modality. Based on individual cases, TACE could be beneficial in maximizing the anti-tumor effect with less toxic side effects.

Systemerkrankungen

Systemerkrankungen als Ursache einer Lebererkrankung sind häufig, ohne dass man genaue Zahlen angeben kann. Die verschiedenen Grunderkrankungen sind für sich betrachtet zwar selten, nur dadurch, dass viele Erkrankungen in Betracht gezogen werden müssen, ergibt sich eine relative Häufung. Durch Fortschritte auf dem Gebiet der molekularbiologischen Diagnostik insbesondere bei den Stoffwechselerkrankungen lassen sich heute bereits viele der in Frage kommenden Grunderkrankungen eindeutig nachweisen. Allerdings ist bei keiner der Erkrankungen ein hundertprozentiger molekularbiologischer Nachweis möglich. Damit ergibt sich eine sichere Diagnose nur bei einem positiven Nachweis. Bei fehlendem Nachweis einer bisher bekannten für die Erkrankung spezifischen Mutation bleibt die Zuordnung entweder enzymatischen Tests oder klinischer Diagnose vorbehalten. Insbesondere bei der Manifestation als akutes Leberversagen ist die für die Diagnosesicherung erforderliche Zeit damit oft nicht vorhanden.

Engineered measles virus Edmonston strain used as a novel oncolytic viral system against human hepatoblastoma

BACKGROUND

Hepatoblastoma (HB) is the most common primary, malignant pediatric liver tumor in children. The treatment results for affected children have markedly improved in recent decades. However, the prognosis for high-risk patients who have extrahepatic extensions, invasion of the large hepatic veins, distant metastases and very high alpha-fetoprotein (AFP) serum levels remains poor. There is an urgent need for the development of novel therapeutic approaches.

METHODS

An attenuated strain of measles virus, derived from the Edmonston vaccine lineage, was genetically engineered to produce carcinoembryonic antigen (CEA). We investigated the antitumor potential of this novel viral agent against human HB both in vitro and in vivo.

RESULTS

Infection of the Hep2G and HUH6 HB cell lines, at multiplicities of infection (MOIs) ranging from 0.01 to 1, resulted in a significant cytopathic effect consisting of extensive syncytia formation and massive cell death at 72-96 h after infection. Both of the HB lines overexpressed the measles virus receptor CD46 and supported robust viral replication, which correlated with CEA production. The efficacy of this approach in vivo was examined in murine Hep2G xenograft models. Flow cytometry assays indicated an apoptotic mechanism of cell death. Intratumoral administration of MV-CEA resulted in statistically significant delay of tumor growth and prolongation of survival.

CONCLUSIONS

The engineered measles virus Edmonston strain MV-CEA has potent therapeutic efficacy against HB cell lines and xenografts. Trackable measles virus derivatives merit further exploration in HB treatment.

Current concepts in pediatric liver tumors

Liver tumors in children can be classified into benign or malignant; some of the benign lesions can have the potential of malignant transformation, and therefore the therapeutic approach may change. These neoplasms account for nearly 1-2% of all pediatric tumors and they have gained significant attention in the last decades due to data suggesting that the incidence may be increasing 5% annually. We know that with new and improved imaging modalities some of these lesions may be detected more often than before. Recent studies showed that liver cancer represented 2% of malignancies in infants by 1980s and this was doubled in incidence to 4% in the following 10 yr. In this review our aim is to discuss all primary liver tumors in children with attention to their clinicopathological and immunohistochemical features followed by the current standard of care.

Primary malignant liver tumors in children

Liver tumors constitute only 1-4% of all solid tumors in children. Two-thirds of these are malignant. The primary malignant tumors are hepatoblastoma (HB), hepatocellular carcinoma (HCC), rhabdomyosarcoma (RMS), angiosarcoma, rhabdoid tumor, undifferentiated sarcoma and other rarer tumors. Of these HB is the commonest. The diagnosis of HB is based on the radiology, elevated levels of α-fetoprotein (αFP) and the histology/cytology. Staging is essential for risk categorization, risk adapted treatment and prognostication. The commonest staging and risk categorization system used today is PRETEXT system that is being used by nearly all multicentre trials (American, European, German, Japanese) in some way. Treatment of HB is multimodal with surgery and chemotherapy being the main modalities. Survival is not possible without complete surgical resection. Majority of tumors are unresectable at presentation but can be made resectable with chemotherapy, giving a resection rate of more than 85%. Cisplatin is the main stay of chemotherapy and is a part of all multidrug protocols. The 3-y overall survival (OS) today stands at 62%-70% but only 25% patients with metastasis get cured. Panhepatic tumors and those with local factors causing unresectability are now dealt with liver transplantation which has also given a survival rate of nearly 85%. The overall management of HB and HCC has evolved over the past 3 decades giving good long term survival rates for HB, though patients with HCC still do poorly. Successive therapeutic trials have focused attention on increasing the efficiency and reducing the toxicity and long term side effects of the treatment. Among the other uncommon tumors the rhabdoid tumor and angiosarcoma are chemoresistant and have a poor outcome while the undifferentiated sarcoma and rhabdomyosarcoma are now showing better response to the currently used chemotherapy combinations.

Hepatoblastoma: recent developments in research and treatment

Hepatoblastoma is the most common liver tumor of early childhood. According to recent studies its incidence seems to be increasing in North America and Europe. Since new histological variants have been described recently the formerly clear-cut distinction of hepatoblastoma and hepatocellular carcinoma may not be valid anymore and a new histological classification will be inaugurated by an international working group. Recent research identified prognostically relevant gene signatures as well as potential molecular targets for therapy of hepatoblastoma. The multicentric study groups in the USA, Europe and Japan recommend cisplatin based chemotherapy for neoadjuvant and adjuvant treatment. However, their risk stratification systems and general treatment strategies differ substantially. Therefore the four groups agreed to pool their patients' data for an analysis of prognostic criteria which can be used for defining common risk groups. While 90% of standard risk and 65% of high risk hepatoblastomas can be cured, the still dismal outcome of multifocal disseminated and metastasising tumors warrants the investigation of new cytotoxic drugs and substances against specific molecular targets.

Rapamycin blocks hepatoblastoma growth in vitro and in vivo implicating new treatment options in high-risk patients

Activation of the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signalling pathway plays a central role in the formation of hepatoblastoma (HB), the most common liver cancer in childhood. Blocking this pathway with specific mTOR inhibitors such as the immunosuppressant rapamycin is being currently tested for a variety of cancers. Here, we report that rapamycin treatment induced a significant dose-dependent inhibition of cell viability and promoted apoptosis in HB cells in vitro. Moreover, rapamycin inhibited AKT/mTOR signalling by dephosphorylation of the downstream target p70S6 kinase (p70S6K). Most importantly, treating subcutaneous HUH6 xenograft tumour bearing mice orally with 5mg/kg/day rapamycin for three weeks resulted in a striking reduction of tumour growth, as evidenced by reduced volume and weight, and moderately lowered tumour-specific alpha-fetoprotein (AFP) serum levels. The anti-tumourigenic effect was primarily ascribed to a significantly reduced proliferation rate upon p70S6K dephosphorylation, as microvascular density of rapamycin-treated compared to vehicle-treated tumours stayed grossly unchanged. Of uttermost clinical importance, we found no evidence for a feedback-loop activation of AKT in vivo. In conclusion, we demonstrate that rapamycin effectively inhibits HB growth both in vitro and in vivo by blocking AKT/mTOR signalling at the level of p70S6K and that rapamycin should be considered to treat HB patients especially those to be indicated for liver transplantation to benefit from its anti-tumourigenic and immunosuppressive properties.

AFP negative cystic liver lesion in a child should let one think of hepatoblastoma

AFP is still the most important serologic marker for the hepatoblastoma as the most common liver tumor in children. An AFP negative hepatoblastoma is rare. We present the first documented case of an infant with an AFP negative and cystic liver lesion later diagnosed as a fetal hepatoblastoma.

Hepatic hemangioendothelioma presenting as sudden unexpected death in infancy: a case report

The classification of an unexpected infant death as sudden infant death syndrome (SIDS) depends upon a complete autopsy, death scene investigation, and review of medical history to exclude known causes of death. Death from occult neoplastic disease in infancy is extremely rare but is within the broad differential diagnosis of SIDS. We report the sudden and unexpected death of a 1-month-old infant from a hepatic (infantile) hemangioendothelioma. The physiologic mechanism of death was likely cardiac failure induced by the circulatory demands of this large vascular tumor and respiratory compromise from diaphragmatic thoracic incursion. The clinical progression and pathology of these relatively common tumors of infant livers are extremely variable. This case dramatically illustrates the potential for fatal outcome of this tumor, as well as the need for autopsy to determine the cause of sudden and unexpected death in an infant.

Apoptotic protein expression, glycogen content, DNA ploidy and cell proliferation in hepatoblastoma subtyping and their role in prognostication

PURPOSE

To evaluate Bcl-xL, Bax, PCNA, cytokeratin 19 (CK-19), glycogen content and DNA ploidy expression in hepatoblastoma (HB) and their prognostic value.

METHODS

This retrospective study on 26 cases of HB involved DNA ploidy estimations separately for various subtypes on histological sections using image cytometry of Feulgen-stained smears. Glycogen content, PCNA, CK-19, Bax and Bcl-xL expression on tissue sections were evaluated. THE outcome on follow-up (mean 86 months) and Kaplan-Meier survival analysis were performed.

RESULTS

Fetal areas were diploid (84%); embryonal areas were aneuploid (89.47%) (p < 0.001). PCNA labeling index was low in fetal (10.82%) and high in embryonal areas (59.85%) (p = 0.03). CK-19 was negative in fetal, but focally positive in embryonal areas. Bax was negative in fetal (80%) and positive in embryonal areas (88.23%) (p < 0.001); Bcl-xL was more frequently positive in fetal (90%) than embryonal areas (52.94%) (p = 0.02). Fetal cells were rich in glycogen. Kaplan-Meier survival analysis showed good initial radiological response to chemotherapy (p = 0.009), glycogen content (p = 0.0137) and DNA diploid cases (p = 0.0429) were associated with good outcome on univariate analysis. Histology typing (p = 0.085), Bcl-xL (p = 0.689), Bax (p = 0.27), CK-19 (p = 0.281), PCNA (p = 0.689), age (p = 0.24), sex (p = 0.5661), stage (p = 0.24) and α-fetoprotein levels (p = 0.49) were unrelated to outcome. Multivariate analysis showed glycogen content to be the most statistically significant variable (0.024).

CONCLUSION

Fetal and embryonal areas show different staining patterns for PCNA, Bax and Bcl-xL. DNA ploidy and glycogen content are significant prognostic variables.

Focal nodular hyperplasia of the liver in a 5-year-old girl

Focal nodular hyperplasia of the liver is a benign tumor that usually affects young women. Traditionally, its treatment in children has been conservative. As a result of its rarity in childhood, its differential diagnosis with other liver tumors is challenging. We present the case of a 5-year-old girl with a 1-week history of fever and abdominal pain. No definite diagnosis could be obtained after serial imaging and liver biopsy. As a result of uncertainty in the imaging and needle biopsy results, the patient underwent complete tumor resection. Pathology showed focal nodular hyperplasia that affected the right lobe of the liver. After surgery, the child was doing well at 24 months of follow-up.