Tumor necrosis predicts survival following neo-adjuvant chemotherapy for hepatoblastoma

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.

Navigating relapsed hepatoblastoma: Predictive factors and surgical treatment strategy

OBJECTIVE

Hepatoblastoma (HB) is the most common primary hepatic malignancy in childhood. Relapse occurs in more than 50% of high-risk patients with a high mortality due to ineffective salvage therapies. The purpose of this study is to identify risk factors for relapsed HB and predictors of survival in a single tertiary referral center.

METHODS

A retrospective chart review showed 129 surgically treated HB patients from October 2004 to July 2020. Of the cohort, 22 patients presented with relapsed HB. Relapse was defined as re-appearance of malignancy after 4 weeks of normalized AFP and disappearance of all tumors on imaging.

RESULTS

Patients with relapsed HB had a 5-year overall survival (OS) of 45.4% compared to 93.1% in those without relapse (p = 0.001). When comparing PRETEXT IV, microvascular invasion, metastatic disease, and age on multivariate logistic regression, only PRETEXT IV was an independent risk factor for relapsed HB with an OR of 2.39 (95% CI: 1.16-4.96; p = 0.019). Mixed epithelial and mesenchymal HB (12/19, 63.2%) was the most common histology of primary tumors while pure epithelial HB (13/15, 86.6%) was the most common relapsed histology. Combination of surgical and medical therapy for relapsed disease was predictive of survival with an HR of 16.3 (95% CI: 1.783-149.091; p = 0.013) compared to only chemotherapy.

CONCLUSIONS

This study demonstrates that PRETEXT IV staging is an independent predictor of relapsed disease. The most common relapsed histology was epithelial, suggesting a potential selection or resistance of this component. Surgical resection is a critical component of multimodal therapy for relapsed HB.

Interaction between human leukocyte antigen (HLA-C) and killer cell Ig-like receptors (KIR2DL) inhibits the cytotoxicity of natural killer cells in patients with hepatoblastoma

BACKGROUND

Hepatoblastoma (HB) is the most common liver malignancy in childhood with poor prognosis and lack of effective therapeutic targets. Single-cell transcriptome sequencing technology has been widely used in the study of malignant tumors, which can understand the tumor microenvironment and tumor heterogeneity.

MATERIALS AND METHODS

Two children with HB and a healthy child were selected as the research subjects. Peripheral blood and tumor tissue were collected for single-cell transcriptome sequencing, and the sequencing data were compared and analyzed to describe the differences in the immune microenvironment between children with HB and normal children.

RESULTS

There were significant differences in the number and gene expression levels of natural killer cells (NK cells) between children with HB and normal children. More natural killer cells were seen in children with HB compared to normal control. KIR2DL were highly expressed in children with HB.

CONCLUSION

Single-cell transcriptome sequencing of peripheral blood mononuclear cells (PBMC) and tumor tissue from children with HB revealed that KIR2DL was significantly up-regulated in NK cells from children with HB. HLA-C molecules on the surface of tumor cells interact with inhibitory receptor KIR2DL on the surface of NK cells, inhibiting the cytotoxicity of NK cells, resulting in immune escape of tumors. Inhibitors of related immune checkpoints to block the interaction between HLA-C and KIR2DL and enhance the cytotoxicity of NK cells, which may be a new strategy for HB treatment.

Down-Regulation of Activating Transcription Factor 3 (ATF3) in Hepatoblastoma and Its Relationship with Ferroptosis

Purpose

The molecular mechanisms and signal pathways of ferroptosis in hepatoblastoma (HB) have not yet been clarified. In previous studies, activating transcription factor 3 (ATF3) was reported to be correlated with several tumors, but the clinical significance of ATF3 has never been determined. Herein, we investigated the clinicopathological value and mechanisms of ATF3 in regulating ferroptosis in HB.

Methods

The mRNA microarray and RNA-sequencing data of 402 samples from our hospital and public databases were used to estimate ATF3 expression and assess its clinical role in HB. The standard mean difference (SMD) and summary receiver operating characteristic curves were utilized to judge the discrimination ability of ATF3 between HB and non-HB liver tissues. We examined the expression variation of ATF3 in HB cells after the treatment with erastin. We also predicted the target genes of ATF3 as a transcriptional factor from public Chromatin Immunoprecipitation-sequencing data and selected the ferroptosis-related genes for a signaling pathway analysis.

Results

In ten series, the pooled SMD for ATF3 was −0.91, demonstrating that ATF3 expression was predominantly lower in HB than in non-HB liver tissues. ATF3 down-regulation showed moderate potential to distinguish HB from non-HB liver tissues (area under curves = 0.83, 95% confidence interval = 0.79–0.86). Altogether, 4855 putative targets of ATF3 as a transcriptional factor were collected, among which, 60 genes were ferroptosis-related.

Conclusion

The down-regulated ATF3 expression may play a vital role in the occurrence of HB possible partially by regulating ferroptosis.

lncRNA TUG1 regulates angiogenesis via the miR‑204‑5p/JAK2/STAT3 axis in hepatoblastoma

Hepatoblastoma is the most common malignant hepatic tumour type with hypervascularity in early childhood. In recent decades, emerging evidence has proven that long non‑coding RNAs (lncRNAs) serve an important oncogenic role in the pathogenesis of hepatoblastoma. However, the underlying mechanism of lncRNA taurine upregulated 1 (TUG1) in the angiogenesis of hepatoblastoma remains unknown. The expression patterns of TUG1 and microRNA (miR)‑204‑5p were detected in hepatoblastoma tissues and cell lines via reverse transcription‑quantitative PCR and were analysed using a Pearson's correlation test. A tube formation assay was performed using human umbilical vein endothelial cells to assess the vasculogenic activity of treated HuH‑6 cells. ELISA was used to detect the level of the secretory proangiogenic factor VEGFA in the culture media of HuH‑6 cells. A dual luciferase reporter assay was performed to validate the binding relationships of TUG1/miR‑204‑5p and miR‑204‑5p/Janus kinase 2 (JAK2). Moreover, western blotting was conducted to measure the protein expression levels of VEGFA, phosphorylated (p)‑JAK2, JAK2, p‑STAT3 and STAT3. It was identified that TUG1 was upregulated, while miR‑204‑5p was downregulated in hepatoblastoma tissues and cells. TUG1 knockdown inhibited angiogenesis induced by hepatoblastoma cells. Furthermore, miR‑204‑5p was identified as a target of TUG1. The results demonstrated that TUG1 attenuated the inhibitory effect of miR‑204‑5p on the JAK2/STAT3 pathway and promoted angiogenesis in hepatoblastoma cells. In summary, TUG1 was upregulated in hepatoblastoma and suppressed miR‑204‑5p, thereby activating the downstream signalling pathway of JAK2/STAT3 to facilitate angiogenesis. The present findings will provide novel targets for the treatment of hepatoblastoma.

Endovascular approaches in pediatric interventional oncology

The demand for interventional oncological (IO) treatment of pediatric cancers is becoming increasingly common, at least at several tertiary care institutions. The data and techniques used in pediatric IO are largely extrapolated from experience in adult patients. The management of pediatric tumors differs from that in adults in several categories, such as, the curative intent of treatment, wide use of general anesthesia, aggressive pain management, potentially longer hospital stay, variation in chemotherapy dosing etc. Additionally, pediatric cancers are managed by protocols directed by national and international oncology groups such as the Children’s Oncology Group (COG). Consequently, the translation and adoption of these techniques is gradual, but there is a noticeable uptrend due to the growing need. This review will update the current endovascular IO treatments for common pediatric liver, renal, bone and soft tissue tumors.

Impact of microscopically margin-positive resection on survival in children with hepatoblastoma after hepatectomy: a retrospective cohort study

BACKGROUND

Impact of R1 (microscopically margin-positive) resection on survival of patients with hepatoblastoma (HB) remains debatable. This study aimed to compare the long-term outcomes of R0 (microscopically margin-negative) and R1 resection for HB in children after hepatectomy.

METHODS

We retrospectively reviewed files of children with HB who underwent resection at our institution between September 1, 2005, and November 30, 2017. Survival analyses and prognostic factors were evaluated using Kaplan-Meier curves and Cox regression models.

RESULTS

Of 259 patients, 218 (84.2%) underwent R0 and 41 (15.8%) R1 resection. After adjusting for confounding factors, R1 resection demonstrated non-significantly lower overall survival (OS: hazard ratio [HR] = 0.75; 95% CI 0.34-1.64) and shorter event-free survival (EFS: HR = 0.97; 95% CI 0.53-1.78) rates than R0 resection. However, stratified analysis showed significantly increased risk of poor OS and EFS in patients with metastasis and mixed epithelial/mesenchymal pathologic subtype in R1 compared with R0 resection (P values for interactions < 0.05). There was no significant difference between R0 resection with metastasis and R1 resection with metastasis in the incidence of local recurrence (P = 0.494); however, a significant difference in the incidence of local recurrence was seen between R0 and R1 resection for subgroups with mixed pathologic subtypes (P = 0.035).

CONCLUSIONS

With effective chemotherapy, microscopic margin status may not be associated with survival outcome in children with HB undergoing hepatectomy. However, stratified analysis showed that R1 resection might be associated with decreased survival in children with mixed epithelial/mesenchymal HB, compared with R0 resection, and not affect survival outcomes in those with an epithelial subtype and without metastasis.

A Brief Report of Immunohistochemical Markers to Identify Aggressive Hepatoblastoma

Hepatoblastoma (HB) is the most common malignant liver tumor in children. Although survival of patients has improved significantly over the last 2 decades, a significant number of patients do not respond to standard chemotherapy. We conducted a pilot study to understand if there was immunophenotypic difference between tumors that respond well to chemotherapy versus that do not. We selected 10 cases of HB from children presenting at our hospital. All patients had initial tissue diagnosis, underwent chemotherapy followed by surgical resection. The cases were divided into 2 groups: aggressive group with 5 cases (all of which had a poor response to chemotherapy); and a good clinical outcome group with 5 cases (all of which responded well to chemotherapy). We excluded the small cell variant of HB from the study because its poor clinical outcome is well known. To be placed in the aggressive group we used the following criteria: <70% necrosis following chemotherapy or recurrence/distant metastasis following chemotherapy. From tissue obtained before chemotherapy, 1 representative block of formalin-fixed, paraffin-embedded tissue was selected for immunohistochemistry. Following review of published literature, antibodies were selected to detect Survivin, PLK-1, Cytokeratin19 (CK19), N-Myc, Yap, Notch2, Hes1, Hes5, and C-Myc. Our results show that Survivin, CK19, and Yap have a diffuse (>75%) positive staining of tumor cells in the aggressive tumors compared with good outcome tumors. However, staining for Yap was weak. Interestingly, there was loss of nuclear expression of C-Myc in majority of tumor cells in aggressive tumors, whereas nuclear staining was retained in most tumor cells of good responders. The N-Myc and PLK-1 immunostains did not reveal any significant differences in the 2 groups of HB. The immunostains for Notch2, Hes1, and Hes5 showed weak to moderately strong staining in tumor cells, but there was no obvious difference in the 2 groups. Our pilot study suggests that in nonsmall cell HB, diffusely increased expression of Survivin and CK19, and loss of nuclear expression of C-Myc marks the tumors as having an aggressive course.

Target exploration of rhein as a small-molecule necrosis avid agent by post-treatment click modification

Post-labeling of compound 3 indicated that binding to exposed DNA may be an important mechanism of targeting of rhein compounds to necrotic cells.

Prognostic and clinicopathological significance of MLKL expression in cancer patients: a meta-analysis

Background

MLKL is the most important executor of necroptosis pathway. Recent studies have demonstrated that MLKL could serve as a potential prognostic biomarker for cancer patients. However, most studies reported so far are limited in discrete outcome and sample size.

Methods

We systematically searched PubMed, Embase, Web of Science and CNKI to obtain all relevant articles about the prognostic value of abnormally expressed MLKL in patients with any type of tumor. Odds ratios or hazards ratios (HRs) with corresponding 95% confidence intervals (CIs) were pooled to estimate the association between MLKL expression and clinicopathological characteristics or survival of cancer patients.

Results

A total of 6 eligible studies with 613 cancer patients were enrolled in our meta-analysis. Our results demonstrated that decreased expression level of MLKL was significantly associated with poor overall survival (OS) (pooled HR 0.26, 95%CI 0.17–0.40, high/low) and event-free survival (EFS) (pooled HR 0.45, 95%CI 0.23–0.87, high/low) in cancer patients. Furthermore, subgroup analysis divided by type of cancer, sample size, follow-up time and Newcastle–Ottawa Scale (NOS) score showed consistent prognostic value. In addition, our analysis revealed that decreased expression level of MLKL was significantly associated with advanced tumor stage, more lymph node metastasis and older age.

Conclusions

In conclusion, our meta-analysis suggested that decreased MLKL expression might be a convinced unfavorable prognostic factor that could help the clinical decision-making process.

Hepatoblastoma in a child with dextrocardia and possible histopathological alteration reminiscent of hepatocellular carcinoma after neoadjuvant chemotherapy

It is quite unambiguous and interesting that postchemotherapy histology of hepatoblastoma may mimicry that of hepatocellular carcinoma which should be differentiated by proper immunohistochemistry and cytology, if possible, for further management and predict prognosis.

Hepatoblastoma: current understanding, recent advances, and controversies

Introduction: Hepatoblastoma (HB) is the most common primary malignant liver neoplasm in children. Its increasing survival rate is related to the progress in modern imaging, surgical techniques, and new chemotherapy regimens.

Clinical approach: One of the past achievements was the development of the pretreatment extension of disease (PRETEXT) system. Gradually, the HB therapeutic approach has become more individualized with better stratification of patients.

Controversies: These include the need for preoperative chemotherapy and its optimal duration; intensity of preoperative chemotherapy required for locally advanced cases (PRETEXT 4); optimal surgical treatment for locally advanced tumors: aggressive hepatic resections versus liver transplantation; the role of postoperative chemotherapy in the post-transplant setting; the timing and role of metastasectomy in patients with disseminated disease who undergo partial liver resection; and the prognostic significance of several HB pathology variants.

Hepatoblastoma biology: Beta-catenin mutations and the beta-catenin/Wnt pathway play an important role in HB development. There have been at least two molecular signatures in HB published. Unluckily, all of these findings are based on relatively small clinical series and require confirmation.

Conclusion: The treatment of HB started from one and the same therapy for all patients and aimed at increased treatment individualization, but the future seems to lie in biology-driven patient-tailored therapies.

Pre-clinical Evaluation of a Cyanine-Based SPECT Probe for Multimodal Tumor Necrosis Imaging

PURPOSE

Recently we showed that a number of carboxylated near-infrared fluorescent (NIRF) cyanine dyes possess strong necrosis avid properties in vitro as well as in different mouse models of spontaneous and therapy-induced tumor necrosis, indicating their potential use for cancer diagnostic- and prognostic purposes. In the previous study, the detection of the cyanines was achieved by whole body optical imaging, a technique that, due to the limited penetration of near-infrared light, is not suitable for investigations deeper than 1 cm within the human body. Therefore, in order to facilitate clinical translation, the purpose of the present study was to generate a necrosis avid cyanine-based NIRF probe that could also be used for single photon emission computed tomography (SPECT). For this, the necrosis avid NIRF cyanine HQ4 was radiolabeled with ¹¹¹indium, via the chelate diethylene triamine pentaacetic acid (DTPA).

PROCEDURES

The necrosis avid properties of the radiotracer [¹¹¹In]DTPA-HQ4 were examined in vitro and in vivo in different breast tumor models in mice using SPECT and optical imaging. Moreover, biodistribution studies were performed to examine the pharmacokinetics of the probe in vivo.

RESULTS

Using optical imaging and radioactivity measurements, in vitro, we showed selective accumulation of [¹¹¹In]DTPA-HQ4 in dead cells. Using SPECT and in biodistribution studies, the necrosis avidity of the radiotracer was confirmed in a 4T1 mouse breast cancer model of spontaneous tumor necrosis and in a MCF-7 human breast cancer model of chemotherapy-induced tumor necrosis.

CONCLUSIONS

The radiotracer [¹¹¹In]DTPA-HQ4 possessed strong and selective necrosis avidity in vitro and in various mouse models of tumor necrosis in vivo, indicating its potential to be clinically applied for diagnostic purposes and to monitor anti-cancer treatment efficacy.

Tumor histopathological response to neoadjuvant chemotherapy in childhood solid malignancies: is it still impressive?

The management of oncological malignancies has significantly improved over the last decades. In modern medicine, new concepts and trends have emerged paving the way for the era of personalized and evidence-based strategies adapted to the patients’ prognostic variables and requirements. Several challenges do exist that are encountered during the management, including the difficulty to assess chemotherapy response with certainty. Having known that neoadjuvant chemotherapy might be the only solution for a proportion of patients with tumors that are unresectable at diagnosis, emergence of strategies that use risk group-directed therapy became an integral part in the management of oncological malignancies. Tumor histopathological change post neoadjuvant chemotherapy is one of the most important predictors of management outcome and is being used in many chemotherapy protocols as an essential determinant of the most suitable postoperative chemotherapy regimen. Bone tumors are the classic models of this approach; however, other childhood solid tumors show significant variations in outcome as a result of tumor histopathological response to neoadjuvant chemotherapy. The aim of this review is therefore to summarize the significance of histopathological responses seen after neoadjuvant chemotherapy in childhood solid tumors. Moreover, it suggests that the effect on tumor histopathology through modifying neoadjuvant chemotherapy and, on the other hand, toxicities from intensifying adjuvant chemotherapy might either necessitate the change of a number of arm groups in different protocol regimens or include newer chemotherapeutic agents adjuvantly for better outcome and lesser toxicities in poor tumor histopathological responders.

Hepatoblastoma

Hepatoblastoma is the most common primary malignant hepatic tumor of infancy and childhood, occurring predominantly in the first two years of life. The management of hepatoblastoma has changed markedly over the last 3 decades; neoadjuvant chemotherapy is now standard, particularly in unresectable tumors resulting in considerable preoperative tumor shrinkage and sometimes near total ablation of the tumor. A 20 month old infant was incidentally found to have a 7.6cm right sided retroperitoneal tumor on routine screening ultrasonography for left ureteral stenosis. Serum alpha fetoprotein was elevated. Biopsy revealed hepatoblastoma, mixed epithelial and embryonal type without mesenchymal elements. He underwent neoadjuvant chemotherapy. Although the tumor had decreased considerably in size, close proximity to major vascular structures precluded safe resection. Liver transplantation was performed; the explanted liver showed complete tumor necrosis with no residual malignancy. The postoperative course was uncomplicated and he is continuing on sixth cycle of chemotherapy.

Necrosis avid near infrared fluorescent cyanines for imaging cell death and their use to monitor therapeutic efficacy in mouse tumor models

Quantification of tumor necrosis in cancer patients is of diagnostic value as the amount of necrosis is correlated with disease prognosis and it could also be used to predict early efficacy of anti-cancer treatments. In the present study, we identified two near infrared fluorescent (NIRF) carboxylated cyanines, HQ5 and IRDye 800CW (800CW), which possess strong necrosis avidity. In vitro studies showed that both dyes selectively bind to cytoplasmic proteins of dead cells that have lost membrane integrity. Affinity for cytoplasmic proteins was confirmed using quantitative structure activity relations modeling. In vivo results, using NIRF and optoacoustic imaging, confirmed the necrosis avid properties of HQ5 and 800CW in a mouse 4T1 breast cancer tumor model of spontaneous necrosis. Finally, in a mouse EL4 lymphoma tumor model, already 24 h post chemotherapy, a significant increase in 800CW fluorescence intensity was observed in treated compared to untreated tumors. In conclusion, we show, for the first time, that the NIRF carboxylated cyanines HQ5 and 800CW possess strong necrosis avid properties in vitro and in vivo. When translated to the clinic, these dyes may be used for diagnostic or prognostic purposes and for monitoring in vivo tumor response early after the start of treatment.

The Necrosis-Avid Small Molecule HQ4-DTPA as a Multimodal Imaging Agent for Monitoring Radiation Therapy-Induced Tumor Cell Death

PURPOSE

Most effective antitumor therapies induce tumor cell death. Non-invasive, rapid and accurate quantitative imaging of cell death is essential for monitoring early response to antitumor therapies. To facilitate this, we previously developed a biocompatible necrosis-avid near-infrared fluorescence (NIRF) imaging probe, HQ4, which was radiolabeled with 111Indium-chloride (111In-Cl3) via the chelate diethylene triamine pentaacetic acid (DTPA), to enable clinical translation. The aim of the present study was to evaluate the application of HQ4-DTPA for monitoring tumor cell death induced by radiation therapy. Apart from its NIRF and radioactive properties, HQ4-DTPA was also tested as a photoacoustic imaging probe to evaluate its performance as a multimodal contrast agent for superficial and deep tissue imaging.

MATERIALS AND METHODS

Radiation-induced tumor cell death was examined in a xenograft mouse model of human breast cancer (MCF-7). Tumors were irradiated with three fractions of 9 Gy each. HQ4-DTPA was injected intravenously after the last irradiation, NIRF and photoacoustic imaging of the tumors were performed at 12, 20, and 40 h after injection. Changes in probe accumulation in the tumors were measured in vivo, and ex vivo histological analysis of excised tumors was performed at experimental endpoints. In addition, biodistribution of radiolabeled [111In]DTPA-HQ4 was assessed using hybrid single-photon emission computed tomography-computed tomography (SPECT-CT) at the same time points.

RESULTS

In vivo NIRF imaging demonstrated a significant difference in probe accumulation between control and irradiated tumors at all time points after injection. A similar trend was observed using in vivo photoacoustic imaging, which was validated by ex vivo tissue fluorescence and photoacoustic imaging. Serial quantitative radioactivity measurements of probe biodistribution further demonstrated increased probe accumulation in irradiated tumors.

CONCLUSION

HQ4-DTPA has high specificity for dead cells in vivo, potentiating its use as a contrast agent for determining the relative level of tumor cell death following radiation therapy using NIRF, photoacoustic imaging and SPECT in vivo. Initial preclinical results are promising and indicate the need for further evaluation in larger cohorts. If successful, such studies may help develop a new multimodal method for non-invasive and dynamic deep tissue imaging of treatment-induced cell death to quantitatively assess therapeutic response in patients.

The diagnostic and prognostic value of SALL4 in hepatoblastoma

AIMS

To investigate the expression of spalt-like transcription factor 4 (SALL4), a regulator of embryonal development, in three epithelial components of hepatoblastoma (HB) and the relationship between SALL4 expression levels and patients' clinicopathological features.

METHODS AND RESULTS

A total of 115 specimens from 79 patients with HB were selected for immunostaining of SALL4. Nuclear staining was semi-quantified using the immunoreactive score (IS; range: 0-12). SALL4 expression was seen in all embryonal components (mean IS = 8.58) and in 41% of fetal components (mean IS = 0.78). No SALL4 expression was seen in either small cell undifferentiated or mesenchymal components of HB. Neither chemotherapy nor metastasis altered SALL4 expression significantly. High SALL4 expression levels were associated significantly with decreased overall survival (OS) (P = 0.004), event-free survival (EFS) (P = 0.003) and the presence of metastasis (P = 0.049) on univariate analysis. Multivariate analysis identified SALL4 as an independent prognostic predictor for OS (P = 0.029).

CONCLUSIONS

SALL4 is useful for subtyping HB, and high SALL4 expression is associated with decreased survival in HB.

Effects of an early referral system on liver transplantation for hepatoblastoma at Texas Children's Hospital

The purposes of this study were to analyze the effects of an ERS on time to transplantation and to describe our center's experience with OLT for HB. Patients who received OLT for HB between 2000 and 2013 were included. Patient and allograft characteristics, chemotherapy regimens, and prior surgical therapies were examined. The interval between diagnosis and OLT prior to and following the institution of an ERS for transplant was compared. Survival and tumor recurrence were analyzed. Nineteen patients received OLT for HB (mean age 33 months). All children received grafts from deceased donors. Two patients underwent prior resections. Tumor recurred in four patients (21.1%). Both patients who received salvage transplants experienced post-OLT recurrence. Three of the four recurrences occurred in spite of adjuvant chemotherapy. There were three deaths: two from metastatic disease. One- and five-yr survivals were 86.1% and 73.8%. After the institution of the ERS, the mean interval between tissue diagnosis and OLT was significantly reduced. Our series of 19 patients demonstrates a 21% recurrence of HB following OLT despite chemotherapy. Five-yr survival reached 73.8%. A system of early referral can effectively reduce times between diagnosis and transplant.

Undifferentiated Embryonal Sarcoma of the Liver (UESL): A Single-Center Experience and Review of the Literature

Undifferentiated embryonal sarcoma of the liver (UESL) is a rare and aggressive pediatric malignancy. The purpose of this study was to review the clinical, radiologic, and pathologic features and outcome of children with UESL at our institution, in the United Network of Organ Sharing database and to review the existing literature to define the state of the art for children with UESL. Six children were diagnosed with UESL at the Texas Children's Cancer Center between 1993 and 2014, 12 children underwent liver transplantation registered in the United Network of Organ Sharing database, and 198 children with UESL were described in 23 case series during 1978 to 2014. Patients were treated with multimodal treatment approaches including primary surgical resection, neoadjuvant and/or adjuvant chemotherapy, and liver transplantation resulting in overall survival reported between 20% and 100% with significant improvement over the recent years. We show that complete tumor removal remains the key element of treatment and our single-institutional experience and data in the published literature suggest that combination chemotherapy with ifosfamide and doxorubicin to facilitate complete surgical resection is an effective approach to cure children with UESL.

Effect of neoadjuvant chemotherapy on resectability of stage III and IV hepatoblastoma

Background

The potential for surgical resection of primary hepatoblastoma tumours was assessed at diagnosis, and after two and four cycles of neoadjuvant chemotherapy.

Methods

Available radiographic images for patients with stage III and IV hepatoblastoma diagnosed between 1991 and 2008 were reviewed. The extent of disease was determined at diagnosis using the PRETEXT staging system, and after two and four cycles of therapy by POST-TEXT staging. Tumour resectability based on radiographic studies was assessed independently by two surgeons with expertise in hepatic surgery who were blinded to treatment and clinical outcome.

Results

Radiographic images from 20 patients with hepatoblastoma were reviewed. Six of 20 tumours were downstaged after two cycles, and three additional tumours were downstaged following four cycles. All PRETEXT stage III and IV tumours were determined to be surgically unresectable at diagnosis. The number of tumours considered unresectable decreased from 16 of 20 at diagnosis to seven of 20 after two cycles, and to four of 20 after four cycles. Five of the seven tumours that were unresectable after two cycles, and all four tumours that were unresectable after four cycles would have qualified for liver transplant based on radiographic studies.

Conclusion

The majority of stage III and IV hepatoblastomas achieved radiographic resectability after two cycles of chemotherapy. There may be an opportunity for earlier surgical intervention and potential for a reduction in chemotherapy in a considerable number of patients.

Towards an international pediatric liver tumor consensus classification: proceedings of the Los Angeles COG liver tumors symposium

Liver tumors are rare in children, and their diagnoses may be challenging particularly because of the lack of a current consensus classification system. Systematic central histopathological review of these tumors performed as part of the pediatric collaborative therapeutic protocols has allowed the identification of histologic subtypes with distinct clinical associations. As a result, histopathology has been incorporated within the Children's Oncology Group (COG) protocols, and only in the United States, as a risk-stratification parameter and for patient management. Therefore, the COG Liver Tumor Committee sponsored an International Pathology Symposium in March 2011 to discuss the histopathology and classification of pediatric liver tumors, and hepatoblastoma in particular, and work towards an International Pediatric Liver Tumors Consensus Classification that would be required for international collaborative projects. Twenty-two pathologists and experts in pediatric liver tumors, including those serving as central reviewers for the COG, European Société Internationale d'Oncologie Pédiatrique, Gesellschaft für Pädiatrische Onkologie und Hämatologie, and Japanese Study Group for Pediatric Liver Tumors protocols, as well as pediatric oncologists and surgeons specialized in this field, reviewed more than 50 pediatric liver tumor cases and discussed classic and newly reported entities, as well as criteria for their classification. This symposium represented the first collaborative step to develop a classification that may lead to a common treatment-stratification system incorporating tumor histopathology. A standardized, clinically meaningful classification will also be necessary to allow the integration of new biological parameters and to move towards clinical algorithms based on patient characteristics and tumor genetics, which should improve future patient management and outcome.

Analysis of national and single-center incidence and survival after liver transplantation for hepatoblastoma: new trends and future opportunities

BACKGROUND

Liver transplantation (LTx) for hepatoblastoma appears to be increasing. Favorable tumor histology is increasingly linked to survival after surgical resection and could also determine posttransplantation outcomes.

METHODS

To evaluate national trends in tumor and LTx incidence as the basis for observations at some LTx centers, and determinants of survival after LTx for hepatoblastoma, we queried the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) registry representing 9.451% of the U.S. population (1975-2007), the United Network for Organ Sharing (UNOS, 1988-2010, n = 332), and Children's Hospital of Pittsburgh database (CHP, 1987-2011, n = 35).

RESULTS

In the United States, hepatoblastoma cases increased 4-fold, LTx for hepatoblastoma increased 20-fold, and hepatoblastoma surpassed other unresectable liver malignancies requiring LTx by nearly 3-fold. Actuarial 5-year patient survival exceeded 75%. Recurrences in 16% were greater after segmental LTx in the total U.S. experience (P = .049). At CHP, 5 children died from recurrences (n = 4) and sepsis (n = 1). Tumors were epithelial (57%) or mixed epithelial-stromal (42%), Children's Oncology Group stage III (77%) or IV (23%). Recurrences were related to previous pulmonary metastases (P = .016), and tumor necrosis <50% (P = .013), but not to small cell undifferentiated tumor histology (P = NS). Hepatic artery thrombosis was more common after LTx for hepatoblastoma compared with nonmalignant indications (P = .0089). Thirty-three children received pre-LTx chemotherapy, 88.6% with cisplatin, and 85.7% received post-LTx chemotherapy.

CONCLUSION

Outcomes after LTx for hepatoblastoma may benefit from improved detection and treatment of pretransplantation metastases, adequate tumor lysis after chemotherapy, and perioperative antithrombotic agents but are unaffected by undifferentiated tumor histology.