Hepatocellular carcinoma in children and adolescents: results from the Pediatric Oncology Group and the Children's Cancer Group intergroup study

Malignant tumors of the liver in children

This article aims to give an overview of pediatric liver tumors; in particular of the two most frequently occurring groups of hepatoblastomas and hepatocellular carcinomas. Focus lays on achievements gained through worldwide collaboration. We present recent advances in insight, treatment results, and future questions to be asked. Increasing international collaboration between the four major Pediatric Liver Tumor Study Groups (SIOPEL/GPOH, COG, and JPLT) may serve as a paradigm to approach rare tumors. This international effort has been catalyzed by the Children's Hepatic tumor International Collaboration (CHIC) formation of a large collaborative database. Interrogation of this database has led to a new universal risk stratification system for hepatoblastoma using PRETEXT/POSTTEXT staging as a backbone. Pathologists in this international collaboration have established a new histopathological consensus classification for pediatric liver tumors. Concomitantly there have been advances in chemotherapy options, an increased role of liver transplantation for unresectable tumors, and a web portal system developed at www.siopel.org for international education, consultation, and collaboration. These achievements will be further tested and validated in the upcoming Paediatric Hepatic International Tumour Trial (PHITT).

Patient-derived mouse xenografts from pediatric liver cancer predict tumor recurrence and advise clinical management

Identification of new treatments for relapsing pediatric cancer is an unmet clinical need and a societal challenge. Liver cancer occurrence in infancy, 1.5 for million children per year, falls far below the threshold of interest for dedicated drug development programs, and this disease is so rare that it is very difficult to gather enough children into a phase II clinical trial. Here, we present the establishment of an unprecedented preclinical platform of 24 pediatric liver cancer patient-derived xenografts (PLC-PDXs) from 20 hepatoblastomas (HBs), 1 transitional liver cell tumor (TCLT), 1 hepatocellular carcinoma, and 2 malignant rhabdoid tumors. Cytogenetic array and mutational analysis of the parental tumors and the corresponding PLC-PDXs show high conservation of the molecular features of the parental tumors. The histology of PLC-PDXs is strikingly similar to that observed in primary tumors and recapitulates the heterogeneity of recurrent disease observed in the clinic. Tumor growth in the mouse is strongly associated with elevated circulating alpha-fetoprotein (AFP), low rate of necrosis/fibrosis after treatment, and gain of chromosome 20, all indicators of resistance to chemotherapy and poor outcome. Accordingly, the ability of a tumor to generate PLC-PDX is predictive of poor prognosis. Exposure of PLC-PDXs to standards of care or therapeutic options already in use for other pediatric malignancies revealed unique response profiles in these models. Among these, the irinotecan/temozolomide combination induced strong tumor regression in the TCLT and in a model derived from an AFP-negative relapsing HB.

CONCLUSION

These results provide evidence that PLC-PDX preclinical platform can strongly contribute to accelerate the identification and diversification of anticancer treatment for aggressive subtypes of pediatric liver cancer. (Hepatology 2016;64:1121-1135).

YAP Subcellular Localization and Hippo Pathway Transcriptome Analysis in Pediatric Hepatocellular Carcinoma

Pediatric hepatocellular carcinoma (HCC) is a rare tumor which is associated with an extremely high mortality rate due to lack of effective chemotherapy. Recently, the Hippo pathway and its transcriptional co-activator Yes-associated protein (YAP) have been shown to play a role in hepatocyte proliferation and development of HCC in animal models. Therefore, we sought to examine the activity of YAP and the expression of Hippo pathway components in tumor and non-neoplastic liver tissue from 7 pediatric patients with moderately differentiated HCC. None of the patients had underlying cirrhosis or viral hepatitis, which is commonly seen in adults with HCC. This highlights a major difference in the pathogenesis of HCC between children and adults. We found a statistically significant increase in YAP nuclear localization in 100% of tumors. YAP target gene (CCNE1, CTGF, Cyr61) mRNA expression was also increased in the tumors that had the most significant increase in YAP nuclear localization. Based on Ki67 co-localization studies YAP nuclear localization was not simply a marker of proliferation. Our results demonstrate a clear increase in YAP activity in moderately differentiated pediatric HCC, providing evidence that it may play an important role in tumor survival and propagation.

Translational Pharmacokinetic-Pharmacodynamic Modeling and Simulation: Optimizing 5-Fluorouracil Dosing in Children With Pediatric Ependymoma

We previously investigated novel therapies for pediatric ependymoma and found 5‐fluorouracil (5‐FU) i.v. bolus increased survival in a representative mouse model. However, without a quantitative framework to derive clinical dosing recommendations, we devised a translational pharmacokinetic‐pharmacodynamic (PK‐PD) modeling and simulation approach. Results from our preclinical PK‐PD model suggested tumor concentrations exceeded the 1‐hour target exposure (in vitro IC₉₀), leading to tumor growth delay and increased survival. Using an adult population PK model, we scaled our preclinical PK‐PD model to children. To select a 5‐FU dosage for our clinical trial in children with ependymoma, we simulated various 5‐FU dosages for tumor exposures and tumor growth inhibition, as well as considering tolerability to bolus 5‐FU administration. We developed a pediatric population PK model of bolus 5‐FU and simulated tumor exposures for our patients. Simulations for tumor concentrations indicated that all patients would be above the 1‐hour target exposure for antitumor effect.

Hepatocellular Carcinoma in Children: Does Modified Platinum- and Doxorubicin-Based Chemotherapy Increase Tumor Resectability and Change Outcome? Lessons Learned From the SIOPEL 2 and 3 Studies

INTRODUCTION

The aim of this article is to present an experience of two prospective studies from the International Childhood Liver Tumor Strategy Group (SIOPEL 2 [S2] and SIOPEL [S3]) trials and to evaluate whether modified platinum- and doxorubicin-based chemotherapy is capable of increasing tumor resectability and changing patient outcomes.

METHODS

Between 1995 and 2006, 20 patients with hepatocellular carcinoma (HCC) were included in the S2 trial and 70 were included in the S3 trial. Eighty-five patients remained evaluable.

RESULTS

Response to preoperative chemotherapy was observed in 29 of 72 patients (40%) who did not have primary surgery, whereas 13 patients underwent upfront surgery. Thirty-three patients had a delayed resection. Thirty-nine tumors never became resectable. Complete tumor resection was achieved in 34 patients (40%), including seven of those treated with liver transplantation (LTX). After a median follow-up period of 75 months, 63 patients (74%) had an event (a progression during treatment, a relapse after treatment, or death from any cause). Sixty patients died. Twenty-three of 46 patients (50%) who underwent tumor resection died. Eighteen of 27 patients (63%) with complete tumor resection (without LTX) and 20 of 34 patients (59%) with LTX survived. Only one of seven patients (14%) with microscopically involved margins survived. Overall survival at 5 years was 22%.

CONCLUSION

Survival in pediatric HCC is more likely when complete tumor resection can be achieved. Intensification of platinum agents in the S2 and S3 trials has not resulted in improved survival. New treatment approaches in pediatric HCC should be postulated.

Distinct set of chromosomal aberrations in childhood hepatocellular carcinoma is correlated to hepatitis B virus infection

Hepatocellular carcinoma (HCC) is rarely observed in children and adolescents, but it is reported to be correlated with hepatitis B virus (HBV+) infections. This correlation is not easily explained, because in adults, HBV infections lead to the development of HCC only after decades, not within a few years. In HBV+ adulthood HCC, distinct chromosomal imbalances have been observed. Similar analyses have not been reported for childhood HCC. Here, we investigated whether chromosomal changes were associated with childhood HCC. We analysed formalin-fixed paraffin-embedded (FFPE) samples derived from 17 patients, 0-18 years old, who underwent partial hepatectomies due to HBV+ or HBV- associated HCC. In parallel, in 15 cases, we also analysed non-neoplastic liver tissues adjacent to the HCC. All samples were analysed with high resolution, microarray-based, comparative genomic hybridisation (aCGH). Overall, genomic aberrations in childhood HCC resembled those reported for adulthood HCC. In HBV+ HCC samples, chromosomes 1, 6, 7, 9, 17, 19, and 22 were significantly changed compared to those in HBV- HCC samples. Most interestingly, aberrations for chromosomes 7, 8, 9, 11, and 19 were also observed in corresponding non-neoplastic samples. A specific set of chromosomal abnormalities, including gains in chromosomes 8q, 9q, 11q, and 19, was significantly enriched in HBV+ compared to HBV- non-neoplastic tissues. In childhood HCC, HBV+ was correlated to increased chromosomal instability and specific chromosomal imbalances. A subset of aberrations might be essential in HCC carcinogenesis because they occurred in adjacent, non-neoplastic tissues. In particular, the gain in chromosome 19 appeared to be highly important.

Hepatocellular carcinoma in children

Liver tumors are relatively rare in childhood, but may be associated with a range of diagnostic, genetic, therapeutic, and surgical challenges sufficient to tax even the most experienced clinician. This article outlines the epidemiology, etiology, pathologic condition, initial workup, and management of hepatocellular carcinoma in children and adolescents.

Targeting EpCAM (CD326) for immunotherapy in hepatoblastoma

Hepatoblastoma (HB) is the most common liver cancer in children. Recurrence of HB after chemotherapy and surgery is frequent among high-risk patients and is associated with chemoresistance. Immunotherapy may improve poor treatment outcomes in HB patients. Cytotoxic leukocytes of the innate and adaptive immune system including different populations of cytotoxic T cells play a major role in fighting developing tumors. In this setting, monoclonal antibodies may be employed to specifically direct immune responses toward tumor cells. We addressed this issue by using humanized antibodies that recognize the cell surface molecule EpCAM (CD326, overexpressed in hepatic tumor cells) to enhance immune responses against HB. EpCAM was constantly expressed on HB cells and its expression was independent of previous therapy based on the DNA-damaging agent cisplatin. Co-culture assays performed with two well-described HB cell lines and tumor tissue cultures demonstrated that tumor cell lysis by γδ T cells can be dramatically augmented by applying EpCAM-specific monoclonal antibodies. These data emphasize the value of antitumor immune responses and encourage adapting immunotherapeutic regimens to improve the outcome of high risk HB.

HCC prevalence and histopathological findings in liver explants of patients with hereditary tyrosinemia type 1

BACKGROUND

Untreated tyrosinemia type 1 (HT1) is manifested by liver failure associated with renal tubular dysfunction, growth failure, and rickets. The indication for liver transplantation (LT) is restricted to non-responders to 2-(2-nitro-4-trifluoromethylbenzoyl)-1, 3-cyclohexanedione (NTBC) treatment, patients not treated with NTBC or for patients with HCC. The aim of this study is to report on a series of NTBC naive HT1 patients submitted to LT along with the prevalence of HCC in their liver explants.

PROCEDURE

This is a retrospective study of 16 children with HT1 who underwent liver transplantation between January 1993 and December 2012.

CLINICAL FEATURES

liver failure in 12 (75%), growth failure in 4 (25%), rickets in 5 (31.2%), hypertrophic cardiomyopathy in three (18.7%), and renal tubulopathy in seven patients (43.7%). Median AFP level was 64,335 ng/ml. Abdominal CT scans showed multiple nodules in most patients. Histopathology of the explants showed cirrhosis in all patients and HCC in 12 (75%), 3 with microvascular invasion. The majority of the tumors were well differentiated. Patient survival rate was 86% at a median follow-up of 6.6 years. All survivors were tumor-free with no adjuvant chemotherapy.

CONCLUSION

In countries where neonatal screening programs are not effective and NTBC treatment is not widely available, LT still plays an important role in the treatment of children with HT1. An early indication in patients who present with multinodular livers can also serve to treat an otherwise underdiagnosed HCC condition.

Efficacy of neoadjuvant therapy and surgical rescue for locally advanced hepatoblastomas: 10 year single-center experience and literature review

AIM: To report our experience with long-term outcomes after multimodal management therapy.

METHODS: An observational retrospective study was performed containing seven patients with hepatoblastoma (Hbl) treated in our institution, a tertiary referral center, from 2003 to 2011. Demographic, preoperative, surgical, and outcome variables were collected. A survival analysis and a review of the current literature related to combination neoadjuvant chemotherapy and surgical resection on Hbl were performed.

RESULTS: The median age at surgery was 14.4 mo, with a male to female ratio of 4:3. Pretext staging at diagnosis was as follows: stage I, 4 cases; stage II, 2 patients; and stage III, 1 case. Mean pretreatment tumor volume was 735 cm³. Five out of seven patients received neoadjuvant chemotherapy according to SIOPEL-3 or SIOPEL-6 protocols. Tumor volume and alpha-fetoprotein levels significantly dropped after neoadjuvant therapy. Surgical procedures performed included hemihepatectomies, segmentectomies and atypical resection. All patients received chemotherapy after surgery. Median postoperative hospital stay was 8 d. All patients were alive and disease-free after a median follow-up period of 23 mo. With regards to the literature review, seventeen articles were found that were related to our search.

CONCLUSION: Our series shows how multimodal management of Hbl, exhaustive control and a meticulous surgical approach leads to almost 100% complete resection with optimal postoperative results.

A review of 218 pediatric cases of hepatocellular carcinoma

PURPOSE

This study evaluates the incidence trends and clinical outcomes of children with hepatocellular carcinoma (HCC) and assesses factors predictive of patient survival.

METHODS

The Surveillance, Epidemiology, and End Results registry was queried from 1973 to 2009 for all patients between ages 0 and 19 with primary HCC. Demographics, tumor histology, surgical intervention, and patient survival were collected.

RESULTS

Overall, 218 patients were identified. The annual age-adjusted incidence was 0.05 cases per 100,000 in 2009. Fibrolamellar subtype tumors were exclusive to children >5years old and exhibited greater survival compared to non-fibrolamellar subtype (57% vs. 28%, respectively, p=0.002). Tumor extirpation for patients with resectable disease significantly improved overall survival at 5years compared to no surgery (60% vs. 0%, respectively, p<0.0001). Overall 5-, 10- and 20-year survival for the entire cohort was 24%, 23%, and 8%, respectively. Independent prognostic factors of lower mortality according to multivariate analysis were surgical resection (hazard ratio (HR)=0.18), non-Hispanic ethnicity (HR=0.52), and local disease at presentation (HR=0.46).

CONCLUSION

Over the past four decades, the incidence of HCC has remained relatively stable. Children of Hispanic ethnicity have high mortality rates. However, HCC resection for curative intent significantly improves outcomes.

Hepatocellular carcinoma in children: epidemiology and the impact of regional lymphadenectomy on surgical outcomes

BACKGROUND

Factors influencing survival in children with HCC have not been studied. The objective of this study was to identify prognostic factors in pediatric HCC, and to determine whether regional lymphadenectomy is associated with improved survival.

METHODS

We performed a retrospective cohort study using the Surveillance, Epidemiology and End Results (SEER) registry. All patients <20 years old diagnosed with HCC from 1973-2009 were included. Disease-specific survival was compared using Kaplan-Meier statistics and Cox proportional-hazards regression.

RESULTS

We identified 238 patients (139 Male: 99 Female). Overall, 112 (47%) received an operation (resection/transplantation). Observed mortality and adjusted hazard of disease-specific death was greater for females (HR=2.07, p=0.013) and older children. Among operative patients, 44% were documented to have a regional lymphadenectomy. Although demographic factors did not differ between lymphadenectomy and non-lymphadenectomy groups, patients who underwent lymphadenectomy had a greater proportion of metastatic disease (24% vs. 15%) and fibrolamellar HCC (53% vs. 31%). Five-year survival for lymphadenectomy patients was superior to non-lymphadenectomy (70% vs. 57%). Adjusted mortality for lymphadenectomy was also improved relative to non-lymphadenectomy (HR=0.26, p=0.013).

CONCLUSIONS

HCC in children is associated with poor survival, especially among children older than 4 years and girls. In surgical candidates, regional lymphadenectomy may be associated with improved survival.

Clinical characteristics and outcome of hepatocellular carcinoma in children and adolescents

PURPOSE

Hepatocellular carcinoma (HCC) rarely occurs in children and adolescents and has been reported to be highly hepatitis B related more than 10 years ago. However, after global vaccination for hepatitis B virus (HBV), the characteristics and outcome of pediatric HCC remain undefined.

METHODS

Patients with HCC admitted from 2004 to 2010 were retrospectively reviewed in a large tertiary hospital.

RESULTS

45 (1.97 %) pediatric HCC were diagnosed (age ≤18 years), with predominantly male patients (93.3 %). 32 (71.1 %) children were HBV positive, 30 of whom had vertical transmission from their mothers. HBV positivity was associated with liver cirrhosis and portal vein invasion, and thus compromised survival. Advanced disease prevented surgical resection due to large tumor size (>10 cm, 66.7 %), early metastasis (24.4 %), bilateral involvement (57.8 %) and portal vein invasion (46.7 %). The median survival for resectable, transarterial chemotherapy and embolization and untreated patients was 28.6, 4 and 5 months, respectively (p < 0.001). Patients with distal metastasis had significantly poorer survival rate than those without metastasis (p < 0.001).

CONCLUSION

Screening of children whose mothers are HBV carriers is important in early detection of pediatric HCC. HBV-associated HCC in pediatric patients, especially in endemic areas, should be detected earlier for more resectability and improvement of surgical prognosis.

The SPLIT research agenda 2013

This review focuses on active clinical research in pediatric liver transplantation with special emphasis on areas that could benefit from studies utilizing the SPLIT infrastructure and data repository. Ideas were solicited by members of the SPLIT Research Committee and sections were drafted by members of the committee with expertise in those given areas. This review is intended to highlight priorities for clinical research that could successfully be conducted through the SPLIT collaborative and would have significant impact in pediatric liver transplantation.

Radioembolisation for treatment of pediatric hepatocellular carcinoma

Transarterial radioembolisation with yttrium-90 (TARE-Y90), a catheter-directed therapy, has been used extensively in adults to treat primary and secondary hepatic malignancies. To our knowledge, the use of this palliative technique has not been described in children. We present two children with unresectable hepatocellular carcinoma (HCC) treated with TARE-Y90.

The activity of γδ T cells against paediatric liver tumour cells and spheroids in cell culture

BACKGROUND

Chemoresistance and advanced tumour stage at time of diagnosis are the major reasons for poor treatment results in hepatoblastoma (HB) and paediatric hepatocellular carcinoma (HCC). Positive results with transplantation of liver and bone marrow revealed the impact of the immune system on the treatment of liver malignancies.

AIM

Cytotoxic-immune-cells-like natural killer (NK) and T cells are major player in the defence against developing tumours. This study aimed to specifically analyse the ability of ex-vivo expanded γδ T cells to recognise and lyse HB and HCC cell lines in coculture assays.

METHODS

Cell viability after treatment with γδ T cells was evaluated with two HB (HUH6 and HepT1) and one HCC cell line (HC-AFW1) using a MTT-based cytotoxicity assay. The binding of T cells to target cells was monitored using immunofluorescence microscopy.

RESULTS

Incubation of hepatic tumour cell lines with γδ T cells led to a significant decrease in tumour cell viability. This was enhanced by zoledronic acid and histone deacetylase inhibitors. MT110, an EpCAM/CD3-bispecific BiTE antibody could bluntly enhance tumour cell lysis close to completion. γδ T cells efficiently interacted with HB and HCC cells in a spheroid culture model.

CONCLUSION

Bispecific antibodies such as MT110 might be used to intensify the antitumoural effect of γδ T cells in context of adoptive immune cell transfer. Optimised immunotherapeutic strategies might therefore improve the outcome of high risk hepatoblastoma and hepatocellular carcinoma.

Malignant liver tumors

Malignant tumors of the liver comprise a relatively small fraction of the total number of pediatric malignancies. However, these tumors can be a significant cause of morbidity and mortality, and there have been significant therapeutic gains during the past few decades through advances in systemic therapy and surgical treatment. Even in patients with advanced local disease, complete resection is now a possibility because of improvements in liver transplantation techniques. In this review, we will discuss the staging and treatment of common malignant tumors of the liver.

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.

Sorafenib and cisplatin/doxorubicin (PLADO) in pediatric hepatocellular carcinoma

PURPOSE

Overall survival is poor in children with primary unresectable hepatocellular carcinoma. Sorafenib has been shown to significantly improve progression-free survival in adult hepatocellular carcinoma (HCC) patients. We evaluated the experience of PLADO (cisplatin 80 mg/m(2) /day, doxorubicin 2 × 30 mg/m(2) /day) in combination with sorafenib in pediatric HCC patients.

PATIENTS AND METHODS

Clinical data of 12 patients (7-16 years), 7 with unresectable tumor, were retrospectively assessed.

RESULTS

In total 6/12 (50%) patients are in complete remission after a median follow-up of 20 months (4 with PLADO/sorafenib/resection, 2 with liver transplantation after local relapse). Of the seven patients with unresectable tumor, PLADO/sorafenib resulted in partial response (PR) in four, stable disease (SD) in two, and progression in one. Three are alive in CR after complete resection after 12 (alternative therapy after two cycles PLADO/sorafenib), 12 and 18 months (six cycles PLADO/sorafenib), respectively. All four patients with elevated alpha-fetoprotein levels had a marked drop after two cycles. Of the five patients with primary complete tumor resection one is alive disease-free at 27 months. Four had local or metastatic relapses (13, 7, 12, and 13 months), two of whom were rescued by liver transplantation (CR after 25 and 32 months). The main toxicity attributable to sorafenib was a hand-foot skin reaction (HFSR) in seven patients.

CONCLUSION

Sorafenib in combination with PLADO may be a promising approach in pediatric HCC; HFSR was the most important toxicity. Data based on prospective studies are needed to evaluate pharmacokinetics, resectability rates, and survival in pediatric HCC treated with sorafenib.

[Paediatric malignant liver tumours]

Tumours and pseudotumours of the liver are a heterogeneous group of neoplasm including 60% of malignant tumours. Malignant liver tumours account for less than 2% of the lesions in children and vary considerably in incidence throughout the paediatric age range, with hepatoblastoma, rhabdoid tumour of the liver, hemangioendothelioma, biliary tract rhabdomysosarcoma and mesenchymal hamartoma in the first two years of life and hepatocellular carcinoma, focal nodular hyperplasia, and undifferentiated sarcoma in older children and adolescents. Treatment of malignant epithelial tumours is based on the surgical resection of the tumour associated with pre- and postoperative chemotherapy including cisplatinum. Modalities of the treatment are adapted to risk factors. Survival rates at three years are over 80% for localised hepatoblastoma whereas they are less than 30% in hepatocellular carcinomas. The role of targeted therapies still has to be defined.

Hepatoblastoma: Analysis of treatment outcome from a tertiary care center

Aim:

This study was designed to retrospectively review our experience with the multimodality management of hepatoblastomas (HB).

Materials and Methods:

Thirteen patients were treated for HB between 2000 and 2007. The clinical presentations, chemotherapy tolerance and response, surgical procedure undertaken, and complications were analysed.

Results:

Median age of the population was 12 months (3-60 months), with a male-to-female ratio of 3.3:1. Nine patients were treated with neoadjuvant chemotherapy incorporating cisplatin and adriamycin. Primary surgery was done in four patients. Extent of hepatic resection in the operated patients varied. Mixed type was the predominant histopathological diagnosis. Adjuvant chemotherapy was well tolerated with no morbidity or mortality. Five-year event-free survival (EFS) and overall survival (OS) of all the 13 patients is 76.9%. All the nine patients who could complete multimodality treatment are alive with no evidence of disease or complications with median follow-up of 63 months (46-122 months).

Conclusions:

Treatment of HB with multidisciplinary approach was well tolerated. OS and EFS of patients were comparable with published studies.

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.

Liver neoplasia in children

Management of pediatric liver tumors has significantly improved over the last 2 decades. The management options for hepatocelluar carcinoma (HCC) are not well defined. In the pediatric context, the main clinical aims are to reduce chemotherapy toxicity (predominantly ototoxicity and nephrotoxicity) in children treated for hepatoblastoma and to investigate additional modes of treatment for HCC. An increasing number of children develop HCC in the background of chronic liver disease, and screening methods need to be better observed.

Selective ligation of portal vein and hepatic artery for ruptured hepatocellular carcinoma in a 13-year-old boy

Hepatocellular carcinoma (HCC) in children is rare, and the prognosis has been poor because of its advanced stage at diagnosis and unresponsiveness to chemotherapy. We report a 13-year-old boy with ruptured HCC in the left trisegment. When hemostasis of the ruptured surface was achieved in the emergency operation, the left branch of the portal vein and the left hepatic artery were ligated at the same time. The volume of the future liver remnant (FLR), that is, his right posterior sector, increased from 56% on admission to 70% of his standard liver volume on day 2. Blood level of serum protein induced by vitamin K absence or antagonist ІІ started to decrease immediately. Left trisegmentectomy was successfully performed 10 days later, followed by chemotherapy. He has been well with a 2-year survival without recurrence. When the FLR is considered relatively small for a major hepatic resection, the selective ligation of the portal vein and the hepatic artery, which feed HCC, seems to be beneficial. This is because it may induce enlargement of the FLR, increasing the safety of the hepatectomy as preoperative portal vein embolization does before a major hepatectomy in adult patients with HCC, and the latter suppresses the tumor while waiting for the planned hepatectomy.

Review of outcomes of primary liver cancers in children: our institutional experience with resection and transplantation

BACKGROUND

Operative intervention plays an important role in the management of primary liver cancers in children. Recent improvements in diagnostic modalities, pre- and postoperative chemotherapy, and operative technique have all led to improved survival in these patients. Both hepatic resection and orthotopic liver transplantation are effective operations for pediatric liver tumors; which intervention is pursued is based on preoperative extent of disease. This is a review of our institution's experience with operative management of pediatric liver cancer over an 18-year period.

METHODS

A retrospective chart review from 1990 to 2007 identified patients who were ≤18 years old who underwent operative intervention for primary liver cancer. Demographics, type of operation, intraoperative details, pre- and postoperative management, as well as outcomes were recorded for all patients.

RESULTS

Fifty-four patients underwent 57 operations for primary liver cancer, 30 of whom underwent resection; the remaining 27 underwent orthotopic liver transplantation. The mean age at diagnosis was 41 months. Twenty patients had stage 1 or 2 disease and 34 patients had stage 3 or 4 disease. Forty-eight (89%) patients received preoperative chemotherapy. Postoperative chemotherapy was given to 92% of patients. Mean overall and intensive care unit duration of stay were 18 and 6 days, respectively. About 45% of patients had a postoperative complication, including hepatic artery thrombosis (n = 8), line sepsis (n = 6), mild acute rejection (n = 3), biliary stricture (n = 2), pneumothorax (n = 2), incarcerated omentum (n = 1), Horner's syndrome (n = 1), and urosepsis (n = 1). Only 6 patients had a recurrence of their cancer, 5 after liver resection, 3 of whom later received a transplant. There was only 1 recurrence after liver transplantation. There was 1 perioperative mortality from cardiac arrest. Overall survival was 93%.

CONCLUSION

Operative intervention plays a critical role in the management of primary liver cancer in the pediatric population. Neoadjuvant chemotherapy can be given if the tumor seems unresectable at diagnosis. If chemotherapy is unable to sufficiently downstage the tumor, orthotopic liver transplantation becomes the patient's best option. Our institution has had considerable experience with both resection and liver transplantation in the treatment of pediatric primary liver cancer, with good long-term outcomes.

High survival rates after liver transplantation for hepatoblastoma and hepatocellular carcinoma

Unresectable malignant liver tumors may be treated by LTx. We evaluated the results of LTx for HB and HCC. All patients transplanted for HB or HCC between 1990 and 2007 were included. Effects of histologic tumor type, primary tumor resection, disease staging, and serum AFP levels at diagnosis and at transplantation on disease recurrence and survival were evaluated. Twelve patients with median age of five (range, 2-16) were transplanted and followed for a median of 11 (2-18) yr. Six patients had HB and six had HCC. At diagnosis, eight patients were staged as PRETEXT III and four patients as PRETEXT IV. Two patients had pulmonary metastases. All patients received neoadjuvant chemotherapy. Median time from diagnosis to LTx was seven (2-133) months. At LTx, none of the patients had radiological evidence of extrahepatic disease, and the median AFP level was 85 (6-15 180) microg/L. No routine chemotherapy after LTx was used.The overall one-, five-, and 10-yr cumulative survival rates were 100%, 80%, and 67%, respectively. Survival was comparable between the two tumor types (4/6 for both). Two deaths occurred secondary to tumor recurrence, one of each tumor type. Both of these patients had an AFP response of <99%. Six of eight patients with primary LTx survived, when compared to two of four transplanted after primary resection. PRETEXT tumor staging had no effect on survival. LTx even without post-transplantation chemotherapy is an effective treatment option for unresectable HB and HCC with comparable survival. Incomplete AFP response to chemotherapy and primary tumor resection were associated with decreased survival.

Tyrosinemia type 1: metastatic hepatoblastoma with a favorable outcome

The clinical course of tyrosinemia type 1 is characterized by acute liver failure in infancy or chronic liver dysfunction and renal Fanconi syndrome in late-presenting cases. Dietary treatment may improve liver function but does not prevent the development of hepatocellular carcinoma (HCC) in late childhood. A new treatment strategy that uses 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC), which prevents the production of toxic/carcinogenic metabolites, has dramatically changed the outcome of the disease by reducing the occurrence of liver cancer, especially in patients who start this treatment before the age of 2 years. We report here the case of a patient with a diagnosis of tyrosinemia type 1 at 5 months of age who was treated with NTBC and dietary restriction and in whom a liver neoplasm with lung metastases, histologically determined to be HCC, was found at the age of 15 months. A conservative approach that consisted of chemotherapy and partial hepatectomy resulted in a 12-year disease-free period. The excellent postchemotherapy course, in sharp contrast to the expected course of HCC, led to histologic reevaluation with reclassification of the neoplasm as hepatoblastoma. A diagnosis of hepatoblastoma would no longer be a mandate for a liver transplant for patients with tyrosinemia type 1 undergoing NTBC treatment. We encourage clinicians to perform more accurate evaluation of liver histology, because a neoplastic mass in a child with tyrosinemia type 1 is not the same as HCC.

Progress in the surgical treatment of malignant liver tumors in children

During the last decade, important progress has been made in the surgical treatment of malignant liver tumors in children. For hepatoblastoma, there is a general consensus for combining surgical resection with neoadjuvant (and adjuvant) chemotherapy. Long-term disease-free survival of around 85-90% can be achieved for resectable HB involving no more than three sections of the liver (PRETEXT I-III). For unresectable HB without extrahepatic invasion (PRETEXT IV with involvement of all four sections and some cases of PRETEXT III with invasion of, or close contact with major venous structures), similar results can be obtained with total hepatectomy and liver transplantation. For hepatocellular carcinoma, most often without underlying liver disease in children of the western world, results of resection with partial hepatectomy remain dismal, due to a high rate of recurrence. In contrast, remarkable survival rates have been obtained during the last decade with liver transplantation. There is no argument, either biological or based on evidence, that the selection of pediatric candidates for transplantation should be based on the same criteria as in adult patients (the Milan criteria). Optimization of results require to concentrate children with a malignant liver tumors in specialized, multidisciplinary pediatric centers with expertise in chemotherapy and in both major liver resections and transplantation. Enrolling these children in prospective trials should be encouraged, as well as prospective registration of transplanted patients in PLUTO (Pediatric Liver Unresectable Tumor Observatory-http://Pluto.cineca.org) in order to clarify issues unresolved by retrospective studies.

Fibrolamellar hepatocellular carcinoma in an infant and literature review

Hepatocellular carcinoma (HCC) is a rare pediatric neoplasm exceptionally reported in infants and fibrolamellar hepatocarcinoma (FLC) a HCC variant. Controversy exists whether FLC has a better prognosis than classic HCC, although recent studies of children and young adults with FLC did not report a better outcome. We present a 4-month-old male infant without any related metabolic or infectious disease who developed a metastatic and multifocal FLC. Serum alpha-fetoprotein determinations were always normal. Induction chemotherapy using cisplatin and Adriamycin resulted in a partial response, however, refractory disease developed and regional metastasis precluded surgical resection. The child died from tumoral progression.

Liver tumors: pediatric population

Liver tumors in childhood are rare and are typically not detected clinically until they reach a large size and often spread within the organ or metastasize. This can make surgical resection problematic, and almost all of them require extirpation for cure. With very effective chemotherapy for hepatoblastoma and to some extent for sarcomas, many cancers can be shrunk to permit partial hepatectomy, but for most hepatocarcinomas, some of the other malignancies, and even some benign proliferations, their location at the hilum and multiplicity of masses in multiple lobes make transplantation the treatment of choice. Major advances in diagnostic imaging, especially enhanced computed tomography and magnetic resonance imaging, permit a preoperative choice of resection versus transplantation to be achieved in almost all instances, and for the remainder, intraoperative ultrasonography can further help to determine the most desirable approach. The outcome is very much better in the case of hepatoblastoma when transplantation is a primary modality rather than following unsuccessful attempts at resection. In this review, transplantation for liver tumors in children is considered from all aspects, including the importance of screening for tumors whenever possible to avoid the need for transplantation.

Role of prognostic factors in the management of pediatric solid tumors

The importance of prognostic factors in predicting outcome in pediatric oncology is largely recognized, and most current protocols tailor treatment based on risk stratification. Further refinements of classical staging systems are ongoing, and the future of pediatric oncology is in the development of strategies based on individual tumor characteristics. This review details significant advances in our understanding of prognostic factors in the most common pediatric solid tumors and potential applications for clinical management.

Prolonged survival with continuous infusion topotecan: a report of 2 cases

Two patients with solid tumors were treated with 21-day continuous infusion topotecan as palliation therapy. Case 1: A 10-year-old girl was diagnosed with progressive, metastatic hepatocellular carcinoma. Twenty-one-day continuous infusion topotecan was started and she has had a partial response. Case 2: A 17-year-old girl developed a malignant fibrous histiocytoma as a second malignant neoplasm. After partial resection and failure of multiagent chemotherapy, she started continuous infusion topotecan and was disease-free for 58 months when she died of pneumonia. These cases suggest that topotecan given as 21-day continuous infusion is efficacious for palliation care.

Hepatocellular carcinoma complicating biliary atresia after Kasai portoenterostomy

Kasai portoenterostomy (PE) increases the survival for children with biliary atresia (BA) and consequently postpones subsequential liver transplantation. All long-term survivors, however, develop complications of biliary cirrhosis. We report a case of hepatocellular carcinoma (HCC) in a 19-year-old male patient with BA and Kasai PE. The preoperative abdominal ultrasound and magnetic resonance imaging showed a large hepatic mass (diameter 10 cm). The serum alpha-fetoprotein level was within normal range. Pathologic findings of the mass, after orthotopic liver transplantation, demonstrated a well-differentiated HCC (T1N0M0). HCC is a rare complication of BA, but will intensively impair the survival. Therefore, clinicians should be alert to the development of HCC in this very young patient group. Repeated sequential magnetic resonance imaging of the native liver in patients with Kasai PE is necessary to monitor possible malignant transformation of liver nodules that may potentially develop as a result of chronic cholestatic liver disease.

Outcomes of primary liver cancer in children: an appraisal of experience

INTRODUCTION

Hepatoblastoma (HB) and hepatocellular carcinoma (HCC) are the most common primary liver cancers in children. Recent advances in management of pediatric liver cancer have improved disease-specific survival (DSS). This is a review of our experience with childhood liver malignancy over the past 3 decades.

MATERIALS AND METHODS

A retrospective chart review from 1975 to 2005 identified patients who were 18 years old or younger with a histologically confirmed diagnosis of primary liver cancer. Patients were staged according to the Children's Cancer Group and Pediatric Oncology Group (CCG/POG) system. Patients were followed up prospectively through clinic visits and mail correspondence. Standard statistical methods were used for comparison, risk, and survival analyses.

RESULTS

Fifty-two patients were confirmed to have primary liver cancers, where 24 (46%) patients had HB, 22 (42%) had HCC, 3 (6%) had sarcomas, and 3 (6%) had other histologies. Mean ages at presentation for HB and HCC were 3.2 and 13.1 years old, respectively. The most common presentations were abdominal mass (67%) and pain (40%). Most patients underwent major liver resection (n = 45, 87%), including: lobectomy (n = 25, 48%), and trisegmentectomy (n = 11, 21%). Three patients underwent liver transplantation (n = 3, 6%) for advanced local disease. Forty-five (87%) received primary or neoadjuvant and/or adjuvant chemotherapy. Patients had the following CCG/POG stages: I (n = 31, 60%), II (n = 6, 11.5%), III (n = 9, 17%), and IV (n = 6, 11.5%). Complete gross resection (stage I and II) was achieved in 37 (71%) patients. The perioperative mortality and morbidity rates were 0% and 29%, respectively. Patients with complete resection had significantly better 5-year DSS and median survival compared with incomplete gross resection: 62% vs 9% and 216 vs 18 months, P < .001. Patients treated during the period 1995-2005 had better 5-year DSS and median survival compared with those treated during 1975-1994: 68% vs 32% and 117 vs 27 months, P = .032. All 3 patients who underwent transplantation for conventionally unresectable disease are alive without disease recurrence (follow-up period, 1-15 years).

CONCLUSION

Complete resection of the pediatric primary liver tumors remains the cornerstone of treatment to achieve cure. Major liver resection can be performed with minimal perioperative mortality and morbidity. Patients with HB appeared to have better survival compared with patients with HCC, and there was significant improvement in the DSS of children treated in the recent decade. Liver transplantation in conjunction with chemotherapy may have an increasing role in the management of locally advanced primary liver cancers.

The role of liver transplantation in the management of paediatric liver tumours

In recent years, considerable progress has been made in the treatment of children with hepatoblastoma largely due to effective pre-operative chemotherapy. Total hepatectomy and liver transplantation has emerged as an effective treatment for the small proportion of children with unresectable hepatoblastoma limited to the liver. A 5-year survival of 70% can be achieved in such cases. In contrast, the results of liver transplantation in children with hepatocellular cancer remain poor because these tumours are usually advanced with evidence of major vascular invasion and/or extrahepatic spread at the time of presentation. An exception is those children in whom the hepatocellular carcinoma is detected during surveillance of chronic liver disease - they typically have smaller tumours and frequently have a good prognosis after liver transplantation. The role of liver transplantation in children with other primary hepatic malignancies remains uncertain because experience is very limited. Liver transplantation is rarely needed in the management of children with benign liver tumours but, if other treatments have failed, it can be a life-saving intervention.

Preliminary experience with arterial chemoembolization for hepatoblastoma and hepatocellular carcinoma in children

The objective of this work was to test feasibility and efficacy of hepatic artery chemoembolization (HACE) in unresectable malignant liver tumors. Five patients aged from 1-12 years were treated in the Medical University of Gdansk from 1999 to 2002. All had locally advanced tumors, which did not respond to systemic chemotherapy: four, hepatoblastoma (HB) and one, hepatocellular carcinoma (HCC). Arteriography was performed and chemoembolization suspension (cisplatin + doxorubicin + mitomycin mixed with lipiodol) was injected, followed by gelatin foam particles. The procedure was performed one to three times in each patient. In four patients (three, HB, one, fibrolamellar HCC), tumor response was observed, with decrease in the diameter of the mass of 25-33% and fall in the AFP level of 83-99%. One child with HB was non-evaluable due to early death caused by systemic myelotoxicity. Two patients (2 HB) underwent macroscopically complete tumor resection, 1 is alive and well, and 1 died at the end of surgery for an unknown reason (possibly related to cardiotoxicity of earlier systemic chemotherapy). One HB patient was successfully transplanted after two HACE courses. The only HCC patient died because of pulmonary oil embolism immediately after the third HACE course. HACE can lead to tumor regression in most cases and may be considered an alternative for patients with unresectable liver tumors who do not respond to primary systemic chemotherapy and are not candidates for liver transplantation for various reasons.

Management of liver tumors in childhood

Primary neoplasms of the liver occur rarely during childhood and constitute only 0.3-2% of all pediatric tumors. However, they comprise a variety of entities including benign and malignant epithelial, as well as mesenchymal tumors, the most common of these being hepatoblastoma and hepatocellular carcinoma. Clinical presentation, especially in young children is relatively uniform with abdominal enlargement and a painless tumor, and often specific symptoms develop late. Prerequisites for clinical diagnosis are a comprehensive laboratory workup and good quality imaging mainly with ultrasound, as well as CT and/or MRI scans. Histological diagnosis is essential for differential diagnosis and may only be omitted in some hepatoblastoma patients of the typical age (6 months to 3 years) with an excessively elevated serum-alpha-fetoprotein. Surgery is the mainstay of treatment for all benign and malignant liver tumors. Hepatoblastomas mostly respond well to chemotherapy. Therefore, this modality should always be combined with surgical resection in these patients and in many cases can reduce the size of a large tumor to resectability. Prognosis nowadays usually is good in all benign tumors and hepatoblastoma, as well as in some other rare malignancies, but dismal in hepatocellular carcinoma and other chemotherapy non-sensitive malignant tumors.

Clinical Characteristics and Prognosis of Pediatric Hepatocellular Carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) is a rare pediatric malignancy that is usually advanced at diagnosis, with a relatively poor prognosis. Extensive treatment, including complete tumor resection, is believed to be necessary for cure. This study was performed to analyze treatment results and to search for prognostic factors of pediatric HCC.

METHODS

Between March 1982 and February 2004 a total of 16 children had been diagnosed as having HCC in our institution, and a retrospective analysis was performed.

RESULTS

The median age at diagnosis was 10.5 years, and the male/female ratio was 11:5. As a predisposing condition, hepatitis B virus (HBV) infections were present in 11 (68.8%) and liver cirrhosis in 8 (50.0%). Including 1 patient with a liver transplant, 4 patients (25.0%) underwent a primary operation with complete tumor resection, and 11 (68.8%) received neoadjuvant chemotherapy because of their inoperable state at diagnosis. After neoadjuvant chemotherapy, complete tumor resection was performed in four (36.4%). Thus complete resection was undertaken in a total of eight patients (50.0%). The estimated 5-year survival rate of all patients was 27.3%. The 5-year survival rate for patients who underwent complete tumor resection was 62.5%, and for those who underwent palliative resection or no operation it was 0%. The statistically significant prognostic factors were tumor stage, presence of metastasis, and complete tumor resection.

CONCLUSIONS

This study confirmed that complete tumor resection is essential for cure in pediatric patients with HCC, and neoadjuvant chemotherapy improves the tumors' resectability.

The contribution of transplantation to the treatment of liver tumors in children

Major progress has been achieved during the last decades in the treatment of malignant liver tumors in children, both in chemotherapy and surgical management. Chemosensitivity varies between tumor types, and radical resection remains essential to effect a cure. In tumors extensively involving a normal liver, in a diffuse or multifocal manner, radical resection cannot be accomplished with a partial hepatectomy. This has been the case for some instances of advanced hepatoblastoma and epithelioid hemangioendothelioma. In hepatoblastoma, current experience shows that results of primary liver transplantation with neoadjuvant chemotherapy are excellent with around an 80% 5-to-10-year disease-free survival rate. Epithelioid hemangioendothelioma is very rarely seen in children and may have a more malignant behavior than in adult patients, and liver transplantation may not be the best management option. In nonresectable hepatocellular carcinoma (HCC) developed on an otherwise normal liver, the results of liver transplantation are similarly poor to those obtained in adult patients, except in a few highly selected series fulfilling the Milano criteria. The experience with HCC is still very scarce in children. Incidental HCC associated with chronic liver disease does not seem to impact posttransplant survival. When they are symptomatic, however, indications for transplantation should be very selective regarding tumor size, multi-focality, vascular invasion and distant metastases.