Pretreatment prognostic factors and treatment results in children with hepatoblastoma: a report from the German Cooperative Pediatric Liver Tumor Study HB 94

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.

Diagnostic and prognostic values of serum exosomal microRNA-21 in children with hepatoblastoma: a Chinese population-based study

BACKGROUND

Hepatoblastoma (HB) is the most common primary malignant tumor of the liver in young children. The aim of this study is to identify the diagnostic and prognostic values of serum exosomal miR-21 in Chinese patients with HB.

METHODS

We retrospectively reviewed 32 children with HB. The expressions of miR-21 were detected by real-time PCR. The comparison of diagnostic performance of plasmatic, exosomal miR-21 and AFP levels was measured using the Area Under ROC Curve.

RESULTS

For patients in HB group, miR-21 concentration was significantly higher in the exosomes compared with the exosome-depleted supernatants and whole plasma. Expression of miR-21 was significantly higher in patients with HB compared with control group in both plasma and exosomes. With respect to the diagnosis of patients with HB, exosomal miR-21 was significantly more accurate compared with the Alpha-fetoprotein levels. Moreover, exosomal miR-21 was an independent predictor of Even-free survival for patients with HB.

CONCLUSIONS

In this study, we found that expression of miR-21 was significantly higher in patients with HB compared with control group in both plasma and exosomes, and we confirmed that exosomal miR-21 could be defined as a diagnostic and prognostic biomarker for patients with HB.

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.

Usefulness of three-dimensional(3D) simulation software in hepatectomy for pediatric hepatoblastoma

BACKGROUND

Hepatoblastoma (HB) is the most common malignant liver tumor in childhood. Complete HB surgical resection which is technically demanding is the cornerstone of effective therapy with a good prognosis. The aim of our study is to evaluate the usefulness of 3D simulation software in assisting hepatectomy in pediatric patients with HB.

METHODS

21 children with HB who underwent hepatectomy were enrolled in this study. All patients underwent computer tomography (CT) imaging preoperatively. CT images from 11 cases (from September 2013 to August 2015) were reconstructed with Hisense CAS, and performed hetpatectomy. While 10 cases (from September 2011 to August 2013) without 3D simulation were token as the control group. The clinical outcome were analyzed and compared between the 2 groups.

RESULTS

All the HB were successfully removed for all patients and there was no positive margins in the surgical specimens, no complications, and no recurrences. For the reconstructing group, 3D simulation software successfully reconstructed the 3D images of liver and were used as a navigator in the operation room during hepatectomy. Anatomic hepatectomy were successfully completed for all patients after operation planning using the software. There was no obvious discrepancy between the virtual and the actual hepatectomy. The mean operation time was shorter (142.18 ± 21.87 min VS. the control group, 173.5 ± 54.88 min, p = 0.047) and intraoperative bleeding was less (28.73 ± 14.17 ml VS. 42.8 ± 41.12 ml, p = 0.011) in the reconstructing group. Moreover, postoperative hospital stay tended to be shorter in the reconstructing group (11.18 ± 2.78d VS. the control group 13 ± 3.46d, P = 0.257).

CONCLUSIONS

3D simulation software facilitates the investigation of the complex liver structure, contributes to the optimal operation planning, and enables an individualized anatomic hepatectomy for each pediatric patient with HB.

Relapsed hepatoblastoma confined to the lung is effectively treated with pulmonary metastasectomy

BACKGROUND

In children diagnosed with hepatoblastoma (HB), the lungs are the most common site of metastasis at both initial presentation and relapse. Previous studies have encouraged pulmonary metastasectomy to achieve a disease-free state after resection of the primary hepatic lesion. However, there is no consensus about how to manage recurrent pulmonary metastasis.

PROCEDURE

A retrospective, multi-institutional review was performed from 2005 to 2014 to identify HB patients ≤18years of age who had disease recurrence associated with pulmonary metastases alone.

RESULTS

Ten patients between the ages of 8 and 33months were identified. Pulmonary metastatic recurrence was detected by measuring alpha-fetoprotein (AFP) levels and/or with CT scans of the chest. All patients subsequently underwent pulmonary metastasectomy without post-operative complications. At last follow-up, 8 patients were alive and had normal AFP levels. The 8 survivors had a median follow-up from therapy completion of 18.5months. Two patients who presented with extrapulmonary recurrence subsequently died of treatment refractory disease.

CONCLUSIONS

This review supports surgical resection as a safe and, in the context of multimodal therapy, efficacious approach to manage HB patients who present with isolated pulmonary relapse.

Benign liver tumors in children: outcomes after resection

PURPOSE

Benign liver tumors in children are rare and data regarding the surgical outcomes are deficient. We reviewed our experience in the management of these tumors particularly the extent, safety, and effectiveness of surgical resection.

METHODS

Between March 2005 and March 2014, 10/90 liver resections were performed for benign liver tumors. Three other patients received conservative treatment. Demographic characteristics, operative management, morbidity, and mortality were analyzed.

RESULTS

The median age of the patients was 12 months. The distribution of pathology was infantile hepatic hemangioendothelioma/hemangioma (n = 7), mesenchymal hamartoma (n = 4), adenoma (n = 1) and focal nodular hyperplasia (n = 1). Median tumor size was 12.25 cm (range 3.5-21 cm) with a median tumor volume of 576.64 cm(3) (range 13.9-1822.64 cm(3)). Non-anatomic resection was performed in 6/10 patients and the median blood loss was 100 ml (range 10-850 ml). Median length of hospital stay was 7 days (range 5-9 days). There were no mortality, none of the patients had a local recurrence, and all are alive at a median follow-up of 33 months.

CONCLUSIONS

Two-third patients with benign liver tumors were managed with surgical excision, which comprised 11% of our resectional practice. Non-anatomical resection whenever feasible can be performed safely and does not compromise the oncological outcomes.

The Children's Hepatic tumors International Collaboration (CHIC): Novel global rare tumor database yields new prognostic factors in hepatoblastoma and becomes a research model

INTRODUCTION

Contemporary state-of-the-art management of cancer is increasingly defined by individualized treatment strategies. For very rare tumors, like hepatoblastoma, the development of biologic markers, and the identification of reliable prognostic risk factors for tailoring treatment, remains very challenging. The Children's Hepatic tumors International Collaboration (CHIC) is a novel international response to this challenge.

METHODS

Four multicenter trial groups in the world, who have performed prospective controlled studies of hepatoblastoma over the past two decades (COG; SIOPEL; GPOH; and JPLT), joined forces to form the CHIC consortium. With the support of the data management group CINECA, CHIC developed a centralized online platform where data from eight completed hepatoblastoma trials were merged to form a database of 1605 hepatoblastoma cases treated between 1988 and 2008. The resulting dataset is described and the relationships between selected patient and tumor characteristics, and risk for adverse disease outcome (event-free survival; EFS) are examined.

RESULTS

Significantly increased risk for EFS-event was noted for advanced PRETEXT group, macrovascular venous or portal involvement, contiguous extrahepatic disease, primary tumor multifocality and tumor rupture at enrollment. Higher age (≥ 8 years), low AFP (<100 ng/ml) and metastatic disease were associated with the worst outcome.

CONCLUSION

We have identified novel prognostic factors for hepatoblastoma, as well as confirmed established factors, that will be used to develop a future common global risk stratification system. The mechanics of developing the globally accessible web-based portal, building and refining the database, and performing this first statistical analysis has laid the foundation for future collaborative efforts. This is an important step for refining of the risk based grouping and approach to future treatment stratification, thus we think our collaboration offers a template for others to follow in the study of rare tumors and diseases.

Rare Tumors in Children: Progress Through Collaboration

Rare pediatric tumors account for approximately 10% of all childhood cancers, which in themselves are a rare entity. The diverse histologies and clinical behaviors of rare pediatric tumors pose challenges to the investigation of their biologic and clinical features. National and international cooperative groups such as the Rare Tumor Committee of the Children's Oncology Group, Rare Tumors in Pediatric Age Project, and European Cooperative Study Group for Pediatric Rare Tumors have developed several initiatives to advance knowledge about rare pediatric cancers. However, these programs have been only partially effective, necessitating the development of alternative mechanisms to study these challenging diseases. In this article, we review the current national and international collaborative strategies to study rare pediatric cancers and alternative methods under exploration to enhance those efforts, such as independent registries and disease-specific, National Cancer Institute-sponsored clinics.

Prognostic significance of aminopeptidase-N (CD13) in hepatoblastoma

BACKGROUND

Hepatoblastoma is a rare childhood malignant tumor that originates from immature hepatic cells. Aminopeptidase-N(CD13), an ectopeptidase that promotes tumor invasion and metastasis, is expressed in fetal stage hepatic progenitor cells, although its role in hepatoblastoma remains unclear.

METHODS

The expression pattern of CD13 was investigated on immunohistochemistry in 30 tissue samples from 27 hepatoblastoma patients (16 with predominantly embryonal [pE] histology and 14 with predominantly fetal [pF] histology). Immunoreactive score (IRS) was used to quantify staining data, and the relationship between CD13 expression, clinicopathological factors, and clinical outcome was investigated. The biological function of CD13 was also examined in the hepatoblastoma cell lines Huh6 and HepG2.

RESULTS

All specimens stained positive for CD13, with higher CD13 expression in pE than in pF hepatoblastoma samples (median IRS, 4; range, 2-9 vs 2; range, 1-4). Strong CD13 expression was correlated with vascular invasion. Five year event-free survival and overall survival were better in patients with CD13(low) than in those with CD13(high) tumors (100% vs 51.0%, P = 0.026; and 100% vs 74.0%, P = 0.114, respectively). A CD13-neutralizing antibody and the potent CD13 inhibitor, Ubenimex, suppressed invasive activity in HepG2 cells in vitro.

CONCLUSIONS

CD13 expression is associated with hepatoblastoma invasiveness and could be a novel prognostic marker for hepatoblastoma.

Icariside II-induced mitochondrion and lysosome mediated apoptosis is counterbalanced by an autophagic salvage response in hepatoblastoma

In this study, the anti-cancer effect of Icariside II (IS), a natural plant flavonoid, against hepatoblastoma cells and the underlying mechanisms were investigated. The in vitro and in vivo studies show that IS decreased the viability of human hepatoblastoma HepG2 cells in a concentration- and time-dependent manner and inhibited tumor growth in mice transplanted with H22 liver carcinomas. IS impaired mitochondria and lysosomes as evidenced by signs of induced mitochondrial and lysosomal membrane permeabilization, resulting in caspase activation and apoptosis. SQSTM1 up-regulation and autophagic flux measurements demonstrated that IS exposure also impaired autophagosome degradation which resulted in autophagosome accumulation, which plays a pro-survival role as the genetic knockdown of LC3B further sensitized the IS-treated cells. Electron microscopy images showed that autophagosome engulfs IS-impaired mitochondria and lysosomes, thus blocking cytotoxicity induced by further leakage of the hydrolases from lysosomes and pro-apoptosis members from mitochondria. In conclusion, these data suggest that IS plays multiple roles as a promising chemotherapeutic agent that induces cell apoptosis involving both mitochondrial and lysosomal damage.

PRETEXT II-III multifocal hepatoblastoma: significance of resection of satellite lesions irrespective of their disappearance after chemotherapy

PURPOSE

To determine the outcomes of resection of satellite lesions in PRE-treatment Tumor EXTension (PRETEXT) II and III multifocal hepatoblastoma irrespective of their disappearance after chemotherapy. To compare the overall outcomes of multifocal and unifocal hepatoblastoma.

METHODS

Fourteen patients with PRETEXT II (n = 7) and III (n = 7) multifocal hepatoblastoma treated between April 2006 and July 2014 were analyzed and their outcomes were compared with PRETEXT II and III unifocal hepatoblastoma treated in the similar period.

RESULTS

Satellite lesion or the affected segments with disappeared satellite lesions were resected in 11 patients. Amongst them, all relapses were distant except one in the liver. In contrast, two of three patients developed liver relapse when the affected segments were not resected. None of the patients receiving intensive chemotherapy based on SIOPEL-3 guidelines developed a relapse. The 3-year event-free and overall survival were 38.6 and 42.9% in multifocal hepatoblastoma and 86.4 and 92.4% in unifocal hepatoblastoma (p = 0.001). Multifocality (p = 0.002) and AFP >10,000 after induction chemotherapy significantly affected event-free survival (p = 0.01).

CONCLUSION

Multifocal hepatoblastoma is associated with poor outcomes as compared to unifocal hepatoblastoma. These preliminary observations of relapse and the role of chemotherapy intensification deserve further study in a multicenter controlled trial setting.

Vincristine-associated neurological morbidity in the treatment of hepatoblastoma

Chemotherapy is an essential component of therapy for infants and children with hepatoblastoma. Vincristine has been a mainstay of chemotherapeutic regimens used by North American cooperative groups, based on indirect evidence of benefit and an assumption of minimal added toxicity. European cooperative group trials have reported comparable survival rates using regimens that omit vincristine. Further examination of the risk and benefit profile of vincristine relevant to hepatoblastoma clinical care paradigms is thus warranted. We evaluated the incidence of vincristine-related sensorimotor peripheral, autonomic, and cranial nerve neurological morbidities in 45 consecutive hepatoblastoma patients treated at our institution. Data suggest an increased risk of vincristine-associated neuropathic grade 2 and 3 events (neuropathic pain and gross motor impairment) in children ages 24 months old or younger, and particularly in children born prematurely. Formal prospective investigation of the relative risks and benefits of vincristine in hepatoblastoma treatment is warranted to assess the value of continued use of vincristine in this patient population.

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.

Impact of postoperative complications on overall survival of patients with hepatoblastoma

BACKGROUND

Complete resection of hepatoblastoma (HB) is a demanding procedure in advanced tumors. Perioperative complications are still common. The influence of complication rates on course of disease and survival of patients with HB has not been analyzed yet.

PROCEDURES

Patients with high risk (HR) HB and standard-risk (SR) HB registered from 1999 to 2008 to the German prospective multicenter study HB99 were evaluated regarding perioperative complications, reasons (e.g., tumor size and vessel involvement) and impact on further treatment and overall survival (OS).

RESULTS

Surgical data from 126 patients were available (47 HR-HB, 79 SR-HB). Postoperative complications occurred in 26 (21%) patients consisting of biliary leakage (n = 9), cholestasis (n = 5), deficit of liver perfusion (n = 5) and others (n = 7). Twenty of these 26 patients (77%) required a second operation. The rate of postoperative complications was higher in the HR-group (26%) compared to the SR-group (17%). Patients with vessel involvement had significantly more complications (17% vs. 54%, P = 0.01). Patients with PRETEXT I/II-tumors had the same rate of postoperative complications (19% vs. 20%) as patients with PRETEXT III/IV. Patients of HR-group with postoperative complications showed delayed start in adjuvant chemotherapy (>21 d) (75% vs. 25%, n.s.) combined with significant lower 5-year-OS (75% vs. 50%, P = 0.02). In multivariate analysis postoperative complications were an independent negative prognostic factor for HR-patients (HR 3.1, P = 0.04).

CONCLUSIONS

Postoperative complications after HB resection are frequent and associated with worsened OS of patients with HR-HB. One possible reason is delay in postoperative chemotherapy. The approach to precarious liver resection should be carefully planned and executed by specialists.

Effective strategy of the combination of high-intensity focused ultrasound and transarterial chemoembolization for improving outcome of unresectable and metastatic hepatoblastoma: a retrospective cohort study

The combination of high-intensity focused ultrasound (HIFU) and transarterial chemoembolization (TACE) has been experimentally performed in a variety of malignant tumors, and its validity has not yet been evaluated for hepatoblastoma (HB). We evaluated the disease-response rate, resection rate, and toxicity in children with unresectable or metastatic HB (stage III and stage IV HB) after sequential treatment with TACE plus HIFU in a controlled clinical trial. The 35 patients with unresectable or metastatic HB were nonrandomly assigned to HIFU ablation (n = 12) or C5V chemotherapy (n = 23). The rates of complete resection, tumor response, and treatment toxicity were evaluated for both regimens. Nine patients who received C5V and 10 patients who received TACE plus HIFU became operable (P = .02). The 3-year event-free survival and overall survival rates were 43.03% and 56.68% in the C5V group and 38.57% and 57.86% in the TACE plus HIFU group, respectively. Acute grade 3 or 4 adverse events, including neutropenia, thrombocytopenia, and anemia, were more frequent in patients treated with C5V therapy than in patients receiving TACE plus HIFU. HIFU ablation achieved a higher rate of complete resection and a lower rate of severe complications compared with C5V treatment in children with advanced HB (Chinese Clinical Trials Registry No. ChiCTR-PRCH-08000182).

Pediatric hepatoblastoma: diagnosis and treatment

Hepatoblastoma (HBL) is the most common primary liver tumor in children, and is usually diagnosed during the first 3 years of life. Collaborative multicenter studies have led to improved diagnostic and treatment strategies. The pretreatment extent of disease (PRETEXT) staging system has become a consensus classification, and an international pathological classification system has also been developed. Clinical trials examining multimodal therapy, which consists of complete surgical resection plus liver transplantation and chemotherapy, have led to improved outcomes for children with HBL. Recently, the Children's Hepatic Tumors International Collaboration (CHIC), which includes major multicenter study groups, created a shared database that merges data on all children underwent therapy in the clinical trials of these groups until 2008. CHIC has developed a global approach to risk stratification of pediatric HBL for use in future global clinical trials. The aim of this review is to report the recent developments on the diagnosis and treatment of pediatric HBL.

Treatment of recurrent primitive neuroectodermal tumors (PNET) in children and adolescents with high-dose chemotherapy (HDC) and stem cell support: results of the HITREZ 97 multicentre trial

Early studies with high-dose chemotherapy for treatment of relapsed cerebral PNET had shown modest efficacy but considerable toxicity. The HIT97 national trial tested a nonrandomized but stratified relapse protocol using either intensive chemotherapy, potentially high dose, or oral chemotherapy. 72 patients (59 disseminated) whose primary treatment had been surgery (97 %), radiotherapy (88 %), and/or chemotherapy (95 %) were enrolled in the intensive chemotherapy arm at diagnosis of relapse or resistance. As a window for this study they received two courses of a 96-hour infusion with carboplatin and etoposide. A response (complete or partial remission) was documented by MRI. Responders received two more cycles of this therapy and stem cell collection, before they received HDC (carboplatin, etoposide, thiotepa) and stem cell support. All possibilities of local therapy were to be explored and applied. After two courses of chemotherapy there was a 52 % response rate (41/72 patients). The median PFS and OS for all 72 patients were 11.6 and 21.1 months. Patients with medulloblastoma had a longer PFS and OS (12.6 and 22.6 months) than those with other PNETs (3.1 and 12.3 months). Favourable prognostic features were no new signs of clinical impairment and localised disease at relapse diagnosis. For the 27 patients who received HDC the median PFS and OS were 8.4 and 20.2 months, respectively. HDC did not benefit patients with resistant cerebral PNET and was associated with profound haematological and mucosal toxicity (90-100 % grade III, IV), infections (50 % grade III and IV) and severe ototoxicity (50 % grade III, 12.5 % grade IV). Treatment related mortality was 8 %. There was low long-term survival and only 2/72 patients are in continuous remission. Adding HDC in patients who responded to the initial courses of chemotherapy did not improve survival. Patients with relapsed cerebral PNET who respond to conventional chemotherapy do not profit from further augmentation to HDC.

Perioperative epidural analgesia in children undergoing major abdominal tumor surgery--a single center experience

PURPOSE

The purpose of this study was to assess the use of continuous epidural analgesia in pediatric patients undergoing major abdominal tumor surgery.

METHODS

Children undergoing major abdominal tumor surgery at our institution between 2008 and 2012 (n=40) received continuous epidural analgesia via an epidural catheter. Surgical trauma scores, pain scores, and clinical data of the children were compared to a pair-matched historical control group operated on between 2002 and 2007 without epidural analgesia.

RESULTS

Pain levels in the study group on day 1 and 3 after surgery were lower compared to the control group. The differences did, however, not reach statistical significance (p=0.15 and 0.09). Children in the study group received significantly fewer additional doses of piritramide or morphine (45% versus 82%, p<0.001). Despite significantly higher surgical trauma scores in the study group (p=0.018), there were no statistical differences regarding clinical parameters, such as mechanical ventilation time, time on intensive care unit, and total hospital stay. There were no catheter-related complications.

CONCLUSIONS

Continuous epidural analgesia is beneficial for children undergoing complex abdominal tumor surgery with regard to pain levels, postoperative recovery, and general clinical course. Expertise of the managing team, a careful patient selection, and a continuous quality assessment are essential for success.

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.

Hepatoblastoma state of the art: pre-treatment extent of disease, surgical resection guidelines and the role of liver transplantation

PURPOSE OF REVIEW

This is part two of a two-part state of the art--hepatoblastoma. International hepatoblastoma specialists were brought together to highlight advances, controversies, and future challenges in the treatment of this rare pediatric tumor.

RECENT FINDINGS

Pretreatment extent of disease (PRETEXT) is a grouping system introduced as part of the multicenter international childhood liver tumors strategy group, SIOPEL-1, study in 1990. The system has been refined over the ensuing years and has now come to be adopted for risk stratification by all of the major pediatric liver tumor multicenter trial groups. PRETEXT is being intensively studied in the current Children's Oncology Group (COG) AHEP-0731 trial in an attempt to validate interobserver reproducibility and ability to monitor response to neoadjuvant chemotherapy, and determine surgical resectability. PRETEXT is now used to identify those patients who are at risk for having an unresectable tumor and who should be referred to a liver specialty center with transplant capability early in their treatment schema.

SUMMARY

International collaborative efforts in hepatoblastoma have led to increased refinements in the use of the PRETEXT and post-treatment extent to define prognosis and surgical resectability. PRETEXT criteria which suggest a possible need for liver transplantation are discussed in detail.

Hepatoblastoma state of the art: pathology, genetics, risk stratification, and chemotherapy

PURPOSE OF REVIEW

As a rare pediatric tumor, hepatoblastoma presents challenges to the individual practitioner as no center will see more than a handful of cases each year.

RECENT FINDINGS

The Children's Hepatic tumor International Collaborative (CHIC) effort has fostered international cooperation in this rare children's tumor, leading to the establishment of a large international collaborative dataset, the CHIC database, which has been interrogated to refine risk stratification and inform treatment options. Apace with this effort has been the international collaboration of pediatric pathologists working together to establish a new international histopathologic consensus classification for pediatric liver tumors as a whole, with particular focus on the histological subtypes of hepatoblastoma.

SUMMARY

International collaborative efforts in hepatoblastoma have led to a new international histopathologic consensus classification, refinements in risk stratification, advances in chemotherapy, and a better understanding of surgical resection options forming the foundation for the development of an upcoming international therapeutic trial.

Is there a role for high dose chemotherapy and blood stem cell rescue in childhood hepatoblastoma presenting with lung metastases? A case report and literature review

We report the use of high dose chemotherapy with peripheral blood stem cell rescue as a consolidation treatment for a 3-year-old child affected by metastatic hepatoblastoma, who achieved complete lung response only after conventional treatment. The patient is presently alive 27 months after high dose chemotherapy with blood stem cell rescue with no evidence of disease.

The role of high dose chemotherapy with blood stem cell rescue to consolidate the complete clearing of lung disease in metastatic hepatoblastoma remains controversial; the data available in the literature and our experience seems to suggest to keep this treatment option open to further consideration in the clinical setting of high-risk patients.

Current therapeutic strategies for childhood hepatic malignant tumors

The two main malignant hepatic tumors in children are hepatoblastomas (HBLs) and hepatocellular carcinomas (HCCs). The past two decades have brought significant improvement to the outcomes of children diagnosed with malignant hepatic tumors, especially HBL, due to improvements in diagnosis and treatment. Histological diagnosis is essential for differential diagnosis of these tumors. In surgery, liver resection has become a safe and secure technique because of progress in anatomical knowledge and surgical dissection; also liver transplantation has become widely used for unresectable tumors. Moreover, the introduction of effective chemotherapeutic regimens has significantly improved the survival of children with HBL due to an increase in the number of patients ultimately undergoing tumor resection, and a reduction in the incidence of post-surgical recurrence. These improvements are the result of multicenter cooperative trials conducted by the Japanese Study Group for Pediatric Liver Tumor, the Children's Oncology Group, and the International Childhood Liver Tumor Strategy Group, including work of the German Association of Pediatric Hematology and Oncology. This paper summarizes the results of these studies and calls on the current international collaboration study called the Children's Hepatic Tumors International Collaboration Project to establish global clinical research on childhood hepatic malignant tumors.

Dose-dense cisplatin-based chemotherapy and surgery for children with high-risk hepatoblastoma (SIOPEL-4): a prospective, single-arm, feasibility study

Background

The objective of this study was to establish the efficacy and safety of a new treatment regimen consisting of dose-dense cisplatin-based chemotherapy and radical surgery in children with high-risk hepatoblastoma.

Methods

SIOPEL-4 was a prospective single-arm feasibility study. Patients aged 18 years or younger with newly diagnosed hepatoblastoma with either metastatic disease, tumour in all liver segments, abdominal extrahepatic disease, major vascular invasion, low α fetoprotein, or tumour rupture were eligible. Treatment consisted of preoperative chemotherapy (cycles A1–A3: cisplatin 80 mg/m² per day intravenous in 24 h on day 1; cisplatin 70 mg/m² per day intravenous in 24 h on days 8, 15, 29, 36, 43, 57, and 64; and doxorubicin 30 mg/m² per day intravenous in 24 h on days 8, 9, 36, 37, 57, and 58) followed by surgical removal of all remaining tumour lesions if feasible (including liver transplantation and metastasectomy, if needed). Patients whose tumour remained unresectable received additional preoperative chemotherapy (cycle B: doxorubicin 25 mg/m² per day in 24 h on days 1–3 and 22–24, and carboplatin area under the curve [AUC] 10·6 mg/mL per min per day intravenous in 1 h on days 1 and 22) before surgery was attempted. After surgery, postoperative chemotherapy was given (cycle C: doxorubicin 20 mg/m² per day in 24 h on days 1, 2, 22, 23, 43, and 44, and carboplatin AUC 6·6 mg/mL per min per day in 1 h on days 1, 22, and 43) to patients who did not receive cycle B. The primary endpoint was the proportion of patients with complete remission at the end of treatment. Analysis was by intention to treat. This trial is registered at ClinicalTrials.gov, NCT00077389.

Findings

We report the final analysis of the trial. 62 eligible patients (39 with lung metastases) were included and analysed. 60 (98%, 95% CI 91–100) of 61 evaluable patients (one child underwent primary hepatectomy) had a partial response to preoperative chemotherapy. Complete resection of all tumour lesions was achieved in 46 patients (74%). At the end of therapy, 49 (79%, 95% CI 67–88) of 62 patients were in complete remission. With a median follow-up of 52 months, 3-year event-free survival was 76% (95% CI 65–87) and 3-year overall survival was 83% (73–93). 60 (97%) patients had grade 3–4 haematological toxicity (anaemia, neutropenia, or thrombocytopenia) and 44 (71%) had at least one episode of febrile neutropenia. Other main grade 3 or 4 toxicities were documented infections (17 patients, 27%), anorexia (22, 35%), and mucositis (seven, 11%). One child died of fungal infection in neutropenia. Moderate-to-severe ototoxicity was documented in 31 (50%) patients. 18 serious adverse events (including two deaths) reflecting the observed side-effects were reported in the trial (the most common was ototoxicity in five patients).

Interpretation

The SIOPEL-4 treatment regimen is feasible and efficacious for complete remission at the end of treatment for patients with high-risk hepatoblastoma.

Funding

Cancer Research UK and Cancer Research Switzerland/Oncosuisse.

Effect of duplex drugs linking 2'-deoxy-5-fluorouridine (5-FdU) with 3'-C-ethynylcytidine (ECyd) on hepatoblastoma cell lines

PURPOSE

Duplex drugs are promising anticancer agents. After in vivo cleavage into active nucleoside analogues, they exert their anti-tumour activity with reduced toxicity and side effects. Here we evaluated the impact of two duplex drugs on the viability of hepatoblastoma (HB) cells lines and their toxicity against human fibroblasts.

METHODS

The duplex drugs 2'-deoxy-5-fluorouridylyl-(3'-5')- 3'-C-ethynylcytidine (5-FdU(3'-5')ECyd) and 3'-C-ethynylcytidinylyl-(5'→1-O)-2-O-octadecyl-sn-glycerylyl-(3'-Ο→5')-2'-deoxy-5-fluorouridine (ECyd-lipid-5-FdU) were analysed in two HB cell lines (HUH6, HepT1) and fibroblasts by MTT assay. The treatment potential was compared to the single substances 2'-deoxy-5-fluorourindine (5-FdU), 3'-C-ethynylycytidine (ECyd) and an equimolar mixture of both. Cell cycle analyses were performed using flow cytometry after 7-AAD staining.

RESULTS

Both duplex drugs achieve a potent cytotoxic effect at low μM concentrations, which was more pronounced than the mixture of ECyd + 5-FdU. Further, both substances exert toxicity on fibroblasts of tumour samples, with less toxicity in foreskin fibroblasts cultures. Cell cycle analyses revealed a shift towards apoptotic cells for both drugs in HB cells.

CONCLUSION

5-FdU(3'-5')ECyd and ECyd-lipid-5-FdU exert a highly potent anti-tumoural effect on HB cells and might therefore be a treatment option in HB. Pharmacological formulations of both duplex drugs have to be evaluated in vivo to reduce possible side effects.

Diagnosis and staging of hepatoblastoma: imaging aspects

Imaging plays a pivotal role in the diagnosis and management of children with hepatoblastoma. However, the continuing evolution of imaging technologies and rarity of hepatoblastoma make validation of imaging approaches challenging. In Europe and other parts of the world staging of hepatoblastoma is based on imaging features while in North America it is based on surgical resectability. In this review we discuss the clinical and imaging features that aid in diagnosing and monitoring children with hepatoblastoma. The potential roles of new imaging techniques are presented, and differences between staging systems are addressed.

Chemotherapeutic approaches for newly diagnosed hepatoblastoma: past, present, and future strategies

Surgical resection is the foundation of therapy in hepatoblastoma (HB), yet most patients have unresectable tumors at diagnosis. Patients with resectable tumors have event-free survival (EFS) of 80-90% and can be cured with cisplatin, 5-fluorouracil, and vincristine. Patients whose tumors are unresectable but without overt metastases at diagnosis have EFS of 60-70%, and many can be rendered resectable without doxorubicin. Children with metastatic disease have fared poorly with 20-50% EFS, and new approaches for these patients remain desperately needed. Dose intensification of cisplatin and doxorubicin appears beneficial in high-risk patients. Future treatment strategies, which may be useful, include increasing intensity and/or duration of therapy, developing a maintenance regimen (oral irinotecan), using liver transplantation more often for patients to undergo complete resection, and identifying and incorporating novel agents. A better understanding of the biologic and pathologic factors is critical for predicting tumor behavior and developing more logical risk-based treatments.

Surgical treatment of hepatoblastoma

Surgical resection remains the cornerstone of cure in hepatoblastoma (HB). Meticulous review of contrast enhanced CT/MR imaging facilitates PRETEXT and POST-TEXT grouping to determine optimal timing and desired extent of liver resection. Excellent knowledge of liver anatomy is essential and the dissection must ensure protection of the vascular inflow and outflow to the remaining liver at all times. Referral to a liver specialty center in advanced cases may facilitate resectability. Potential surgical complications include bleeding, vascular injury, cardiac arrest, liver failure, and bile leak. The risk of complications can be minimized with preoperative planning, appropriate referral, and precise surgical technique.

Imaging of multifocal hepatic lesions in pediatric patients

Imaging plays a vital role in detection and characterization of multifocal liver lesions in children. Numerous causes for these lesions exist, including benign and malignant neoplasms, infectious lesions, and congenital and inflammatory conditions. The imaging spectrum of multifocal liver lesions in children is presented with emphasis on key imaging features, differential diagnoses and helpful relevant clinical features.

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.

Can we predict the prognosis of resectable hepatoblastoma from serum alpha-fetoprotein response during preoperative chemotherapy?

PURPOSE

The objective of this study was to clarify whether the alpha-fetoprotein (AFP) reduction rate during preoperative chemotherapy represents a prognostic factor for hepatoblastoma.

METHOD

We divided 14 hepatoblastoma patients who underwent preoperative chemotherapy and curative resection into Group A (no recurrence; n = 10) and Group B (recurrence; n = 4). We then compared AFP levels before and after preoperative chemotherapy between groups.

RESULT

Mean AFP level after completing the first cycle of chemotherapy was reduced to 7.28 % (range 1.2-36.8 %) in Group A and 17.05 % (range 12.0-20.5 %) in Group B (p < 0.05). Mean AFP after total preoperative chemotherapy was reduced to 1.42 % (range 0.07-8.5 %) in Group A and 7.55 % (range 3.4-12.4 %) in Group B (p < 0.02). Eight patients in whom AFP levels decreased >1 log after the first cycle of preoperative chemotherapy survived without recurrence.

CONCLUSION

A large, early decrease in AFP level during preoperative chemotherapy may offer a strong indicator of survival. Patients in whom AFP levels do not decrease easily during preoperative chemotherapy may have increased risk of recurrence and should be followed very closely.

Tumor necrosis predicts survival following neo-adjuvant chemotherapy for hepatoblastoma

BACKGROUND

Tumor response to chemotherapy has been shown to predict outcome in children with acute lymphoblastic leukemia, osteosarcoma, and Ewing Sarcoma. We evaluated whether tumor necrosis following neo-adjuvant chemotherapy is prognostic for survival in hepatoblastoma (HB).

PROCEDURE

Primary tumors from children with newly diagnosed stage III and IV HB who underwent surgical resection following neo-adjuvant chemotherapy were evaluated histologically for the extent of tumor necrosis (total diameter of necrotic and fibrotic tissue divided by total diameter of tumor). Clinical features, laboratory values, pathological features, treatment delivered, and vital status were recorded. Univariate and multivariate Cox regression analyses were performed to evaluate prognostic factors.

RESULTS

Thirty-two patients were evaluable. After a median of four cycles of neo-adjuvant chemotherapy gross total surgical resection was achieved in 29 patients and complete resection documented by histology in 22 patients. Three-year event free survival (EFS) and overall survival (OS) of the evaluable patients were 70.3 ± 8.3% and 76.8 ± 7.6%, respectively. Extent of tumor necrosis, platelet count at diagnosis, decline in serum alpha fetoprotein, and surgical margin status (positive vs. negative) were statistically significant predictors for both EFS and OS by univariate analysis. Multivariate analyses revealed that extent of tumor necrosis and surgical margin status predicted improved EFS (P < 0.001) and OS (P < 0.0001).

CONCLUSIONS

Extent of tumor necrosis following neo-adjuvant chemotherapy is an independent prognostic factor in patients with newly diagnosed HB. Histological response may potentially be used in strategies to modify post-surgical therapy to improve survival in HB.

Current and future management strategies for relapsed or progressive hepatoblastoma

Hepatoblastoma is the most common primary malignant neoplasm of the liver in children. Improvements in chemotherapy and surgical techniques have increased survival rates for those with localized disease. The prognosis for patients with progressive or relapsed disease continues to be dismal. Complete resection by surgery or liver transplantation is necessary for cure. Few conventional chemotherapy agents have demonstrated activity in progressive or relapsed hepatoblastoma. Irinotecan has shown activity in relapsed and progressive hepatoblastoma. The efficacy of high-dose chemotherapy in this setting is unknown. Newer targeted agents that 'selectively' interfere with pathway targets involved in tumor growth and progression such as insulin-like growth factor, phosphatidylinositol 3-kinase (PI3K), Akt, and mammalian target of rapamycin (mTOR) are currently under development. Because of the rarity of hepatoblastoma, only a small minority of these agents will ever be evaluated in children with this disorder. Gene-directed therapy and immunotherapy have shown promising results in the preclinical setting, and should be investigated as future treatment options for advanced hepatoblastoma.

Surgical complications in pediatric surgical oncology

Rates of surgical complications in pediatric oncological patients increase with the extension of tumor surgery. Especially in advanced tumors this can mean a relevant challenge to surgeons: The balance between risk of complications and success of surgical treatment is often difficult to accomplish. As a consequence, surgeons not only need profound knowledge about resection techniques and surgical standard procedures but they also have to be able to control and manage surgical complications during and after surgery. This article highlights background and spectrum as well as management of selected surgical complications during or after surgery for abdominal pediatric solid tumors.

Changing treatment and outcome of children with hepatoblastoma: analysis of a single center experience over the last 20 years

BACKGROUND/PURPOSE

The aim of the study was to analyze changing management and survival of children with hepatoblastoma (HBL) treated in one center.

MATERIALS AND METHODS

Over the last 20 years, 51 children with HBL were treated. Surgery was performed in 48 children (94.1%), conventional liver resection in 38 (of those, 2 received a rescue liver transplantation [LTx] for relapse), and total hepatectomy and primary LTx in 10 patients. The remaining 3 patients received only palliative treatment. Patient data were analyzed for survival with respect to PRETreatment EXTent of disease (PRETEXT), metastases, histopathology, conventional resection, and LTx.

RESULTS

Survival of children with HBL treated with liver resection is 71% and 80% for primary LTx. Favorable prognostic factors for patient survival was tumor histology as epithelial-fetal subtype and mixed epithelial and mesenchymal type, without teratoid features, and good response to chemotherapy (necrosis, fibrosis). Unfavorable prognostic factors were small cells undifferentiated, transitional liver cell tumor, α-fetoprotein level above 1,000,000 IU/mL and below 100 IU/mL at diagnosis, lung metastases, and local recurrence after initial resection. Survival was related to PRETEXT stage. However, among patients with PRETEXT III and IV, LTx resulted in better survival.

CONCLUSION

Liver transplantation is a good option for children with advanced HBL. Early referral of children with potentially unresectable tumors to centers where combined treatment (chemotherapy, surgery including LTx) is available is crucial.

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.

Treatment effects of the multikinase inhibitor sorafenib on hepatoblastoma cell lines and xenografts in NMRI-Foxn1 nu mice

BACKGROUND

Multidrug resistance is a major reason for poor treatment results in advanced hepatoblastoma (HB). Several alternative treatment options are currently under investigation to improve the prognosis of affected patients

AIMS

This study aimed to analyse the impact of sorafenib on the viability of HB cells and xenotransplanted HB tumours.

METHODS

Cell viability and apoptosis were evaluated in two HB cell lines (HUH6 and HepT1) after treatment with sorafenib using MTT and Caspase 3 activation assay. Extracellular signal-regulated kinase (ERK) phosphorylation was investigated using Western blot. In addition, sorafenib (30 mg/kg) was administered orally to NMRI mice bearing subcutaneous HUH6 derived tumours. Tumour progression and viability were monitored by tumour volume and α-fetoprotein (AFP) levels, and apoptosis was assessed using TUNEL assay. Tumour angiogenesis and mean vascular density (MVD) was determined using CD31 staining, ERK phosphorylation was detected using indirect immunofluorescence.

RESULTS

Treatment with sorafenib led to decreased ERK phosphorylation, reduced cell viability and induction of apoptosis in HepT1 and HUH6 cells. In HB xenografts, sorafenib significantly reduced tumour growth compared with control (P < 0.05). AFP levels were lower in the sorafenib group (P = 0.07). Relative apoptotic areas detected using TUNEL assay were increased (P = 0.003). CD31 staining revealed inhibition of angiogenesis, and mean vascular density was lower in the sorafenib group (P = 0.02). ERK phosphorylation was reduced in tumours tissues after sorafenib treatment.

CONCLUSION

Treatment with sorafenib led to a potent inhibition of cell viability, tumour progression and angiogenesis. Sorafenib might therefore also be a promising treatment option for high risk or recurrent HB.

IGFBP3 impedes aggressive growth of pediatric liver cancer and is epigenetically silenced in vascular invasive and metastatic tumors

Background

Hepatoblastoma (HB) is an embryonal liver neoplasm of early childhood with a poor prognosis for patients with distant metastases and vascular invasion. We and others have previously shown that the overexpression of insulin-like growth factor 2 (IGF2), loss of imprinting at the IGF2/H19 locus, and amplification of pleomorphic adenoma gene 1 (PLAG1) are common features in HB, suggesting a critical role of the IGF axis in hepatoblastomagenesis. In this study, we investigated the role of the insulin-like growth factor binding protein 3 (IGFBP3), a known competitor of the IGF axis, in pediatric liver cancers.

Results

The IGFBP3 gene was highly expressed in normal pediatric livers but was heavily downregulated in four HB cell lines and the majority of HB primary tumors (26/36). Detailed methylation analysis of CpG sites in the IGFBP3 promoter region by bisulfite sequencing revealed a high degree of DNA methylation, which is causatively associated with the suppression of IGFBP3 in HB cell lines. Consequently, the treatment of HB cell lines with 5-aza-2'-deoxycytidine resulted in DNA demethylation and reactivation of the epigenetically silenced IGFBP3 expression. Interestingly, IGFBP3 promoter methylation predominantly occurred in metastatic HB with vascular invasion. Restoring IGFBP3 expression in HB cells resulted in reduced colony formation, migration, and invasion.

Conclusion

This study provides the first direct evidence that the reactivation of IGFBP3 decreases aggressive properties of pediatric liver cancer cells and that IGFBP3 promoter methylation might be used as an indicator for vessel-invasive tumor growth in HB patients.

Apoptosis sensitizers enhance cytotoxicity in hepatoblastoma cells

PURPOSE

Drug resistance remains a major challenge for the treatment of high-risk hepatoblastoma (HB). To enhance effectiveness of chemotherapy we modulate apoptosis in HB cells in vitro.

METHODS

Viability was monitored in HB cells (HuH6, HepT1) and fibroblasts in monolayer and spheroid cultures treated with ABT-737, obatoclax, HA14-1, and TW-37 and each in combination with CDDP, etoposide, irinotecan, paclitaxel, and DOXO in a MTT assay. Western blot analyses were performed to determine expressions of pro- and anti-apoptotic proteins.

RESULTS

Obatoclax and ABT-737 led to a dose-dependent decrease of viability in HB cells at concentrations above 0.3 μM. TW-37 and HA14-1 were less effective. ABT-737 and obatoclax had additive effects when combined with CDDP, etoposide, irinotecan, paclitaxel, or DOXO. This was also observed for fibroblast, however, for higher drug concentrations. In spheroid cultures, relative expression of Bcl-XL was increased, Bax was decreased, Mcl-1 was low, and Bcl-2 was not detected compared to 2D cultures, denoting an anti-apoptotic state in spheroids. Obatoclax and ABT-737 have overcome the resistance to CDDP. HuH6 cells have shown higher susceptability for apoptosis sensitizers than HepT1.

CONCLUSION

The data provide evidence that ABT-737 and obatoclax might improve treatment results in children with HB.

Surgical treatment of lung metastases in patients with embryonal pediatric solid tumors: an update

Distant metastases regularly occur in children with solid tumors. The most affected organ is the lung. Nearly in all extracranial pediatric solid tumors, the presence of lung metastases is associated with an adverse prognosis for the children. Therefore, the correct treatment of lung metastases is essential and influences the outcome. Despite different national and international trials for pediatric tumor entities, specific surgical aspects or guidelines for lung metastases are usually not addressed thoroughly in these protocols. The aim of this article is to present the diagnostic challenges and principles of surgical treatment by focusing on the influence of surgery on the outcome of children. Special points of interest are discussed that emphasize sarcomas, nephroblastomas, hepatoblastomas, and other tumors. Surgery of lung metastases is safe, has a positive impact on the patients' prognosis, and should be aggressive depending on the tumor entity. An interdisciplinary approach, including pediatric oncology and radiology, is mandatory in any case.

Inhibition of autophagy may suppress the development of hepatoblastoma

Hepatoblastoma (HB) is a rare cancer but represents the most common liver malignancy in children under 3 years of age. Nevertheless, a clear understanding of the pathogenesis is lacking. Although the treatment of HB has been dramatically improved by combining chemotherapy regimens with surgery, its fatal outcome of fast development and recurrence makes new treatment strategies for HB, based on an improved understanding of the pathogenesis, essential. Autophagy is believed to be important in the progression of cancers. However, the role of autophagy in HB remains to be elucidated. Here, we show that autophagy is activated in HB tissues and cells under the conditions of starvation or chemotherapy, coupled with the over-expression of autophagic-related genes BECN1 and ATG5. Suppression of autophagy with pharmacological agents and small interfering RNAs significantly increased cell apoptosis and retarded proliferation in response to nutrition deprivation and treatment with chemotherapeutics. Our data demonstrate that the BECN1 and ATG5-dependent phosphoinositide 3-kinase (PI3K) signaling pathway is essential for the survival of HB cells and their tolerance to chemotherapy and starvation-induced death, and suggests that modifying such autophagic genes may suppress the development of HB, thus offering a therapeutic potential for patients with HB.

Prognostic implications of serum alpha-fetoprotein response during treatment of hepatoblastoma

BACKGROUND

We evaluated the outcomes and prognostic factors, especially serum levels of alpha-fetoprotein (AFP) and their changes during the treatment of hepatoblastoma (HB).

PROCEDURE

We retrospectively analyzed the medical records of 43 consecutive children with HB treated at a single institution between 1991 and 2010.

RESULTS

Of 43 patients, 5 (12%) underwent primary tumor resection at diagnosis and 38 (88%) received preoperative chemotherapy. Of those 38 patients, 7 (16%) died of progressive disease during preoperative chemotherapy, and 31 (72%) underwent curative operations, including 5 who underwent liver transplantation, after a median 4 cycles of chemotherapy (range, 3-14 cycles). The 5-year overall survival and disease-free survival rates were 62.1 ± 8.3% and 65.6 ± 7.6%, respectively. AFP >263,000 ng/mL at diagnosis, a decline of <1 log in AFP levels after the first cycle of chemotherapy, preoperative AFP levels in the highest tertile, and postoperative AFP levels in the highest tertiles were significantly associated with treatment failure. Age younger than 1 year at diagnosis, thrombocytosis at diagnosis, and early PRETEXT (pretreatment extent of disease) stage were significantly associated with better survival outcomes, whereas gender and metastasis were not. Multivariate analysis showed that high level of preoperative AFP was an independent predictor of treatment failure.

CONCLUSIONS

Serial monitoring of changes in AFP levels during the treatment, especially perioperative changes, may help identify favorable and poor responders to chemotherapy. Alternative treatment, such as liver transplantation, should be considered for poor responders.

Rhabdoid tumors of the liver: rare, aggressive, and poorly responsive to standard cytotoxic chemotherapy

BACKGROUND

Rhabdoid tumors of the liver are rare tumors that are difficult to cure. We compiled all the cases previously reported in the literature to review clinical data, treatments, and outcomes.

PROCEDURE

Patients were identified by literature review using PubMed.

RESULTS

Thirty-four patients were identified. The median age at presentation was 8 months. All patients with reported AFP results exhibited normal or minimally increased serum AFP levels. All 10 tumors with reported INI1 immunohistochemistry results were reported as negative. Twenty-one patients presented with metastatic disease at diagnosis. Thirty patients died of disease or treatment complications. Most deaths occurred within 12 months after diagnosis. Five patients survived at the time of the reports with one patient alive with disease. One patient relapsed and subsequently died after the report was published. Of the four patients alive without disease, all were treated with chemotherapy, and at least three had surgery or transplantation. Two patients received radiation therapy but did not survive.

CONCLUSIONS

Rhabdoid tumors of the liver are aggressive, rare tumors of the infant liver that are often associated with metastases at the time of diagnosis. Mortality is high and often occurs soon after diagnosis. Treatment with aggressive chemotherapy in combination (especially an alkylating agents doxorubicin) with complete resection may lead to improved outcomes. Therapy targeted to the INI1 mutation of these tumors is currently being investigated and may offer greater hope of cure.

The BH3 mimetic ABT-737 increases treatment efficiency of paclitaxel against hepatoblastoma

Background

The primary goal of current chemotherapy in hepatoblastoma (HB) is reduction of tumour volume and vitality to enable complete surgical resection and reduce risk of recurrence or metastatic disease. Drug resistance remains a major challenge for HB treatment. In some malignancies inhibition of anti-apoptotic pathways using small BH3 mimetic molecules like ABT-737 shows synergistic effects in combination with cystotoxic agents in vitro. Now we analysed toxicology and synergistic effects of this approach in HB cells and HB xenografts.

Methods

Viability was monitored in HB cells (HUH6 and HepT1) and fibroblasts treated with paclitaxel, ABT-737 and a combination of both in a MTT assay. HUH6 xenotransplants in NOD/LtSz-scid IL2Rγnull mice (NSG) were treated accordingly. Tumour volume and body weight were monitored. Xenografted tumours were analysed by histology and immunohistochemistry (Ki-67 and TUNEL assay).

Results

ABT-737 reduced viability in HUH6 and HepT1 cells cultures at concentrations above 1 μM and also enhanced the cytotoxic effect of paclitaxel when used in combination. Thereby paclitaxel could be reduced tenfold to achieve similar reduction of viability of tumour cells. In contrast no toxicity in fibroblasts was observed at the same regiments. Subcutaneous HB (HUH6) treated with paclitaxel (12 mg/kg body weight, n = 7) led to delayed tumour growth in the beginning of the experiment. However, tumour volume was similar to controls (n = 5) at day 25. Combination treatment with paclitaxel and ABT-737 (100 mg/kg, n = 8) revealed significantly 10 fold lower relative tumour volumes compared to control and paclitaxel groups. Paclitaxel dependent toxicity was observed in this mice strain.

Conclusions

Our results demonstrate enhancement of chemotherapy by using modulators of apoptosis. Further analyses should include improved pharmacological formulations of paclitaxel and BH3 mimetics in order to reduce toxicological effects. Sensitising HB to apoptosis may also render resistant HB susceptible to established chemotherapy regimens.

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.

Critical review of controversial issues in the management of advanced pediatric liver tumors

Hepatocellular carcinoma (HCC) and hepatoblastoma (HB) are the most common primary tumors of liver in children. The management of patients with locally advanced, unresectable disease or those with extra-hepatic distant metastases provides substantial challenges to pediatric oncologists, hepatologists, and surgeons. Herein, we critically debate the two sides of three specific controversies: (1) the role of chemotherapy in the treatment of advanced pediatric HCC; (2) the indications for liver transplantation in children with HCC, specifically, the appropriateness of using adult Milan criteria; and (3) the role of liver trasplantation in children with unresectable HB that present with metastatic disease. Pediatr Blood Cancer 2011;56:1013-1018. © 2010 Wiley-Liss, Inc.