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

Chemoresistant hepatoblastoma in a patient with mosaic trisomy 18 treated with orthotopic liver transplantation

We present a 9-month-old male with mosaic trisomy 18 with a right hepatic lobe mass. The tumor was completely resected and identified as pure fetal histology hepatoblastoma but contained increased mitotic activity. Adjuvant chemotherapy consisted of cisplatin, vincristine, and 5-fluorouracil. After the first and fourth cycles of chemotherapy, recurrent tumor developed. The patient underwent rescue orthotopic liver transplantation, and is currently alive without evidence of hepatoblastoma 28 months after transplantation. This report demonstrates the use of orthotopic liver transplantation in a child with mosaic trisomy 18 and hepatoblastoma.

MicroRNA-492 is processed from the keratin 19 gene and up-regulated in metastatic hepatoblastoma

MicroRNAs (miRNAs) are well-known regulators of proliferation, apoptosis, and differentiation and are recognized to play an important role in the development of cancers. Here we aimed to identify the functional contribution of miRNAs to the biology of hepatoblastoma (HB), the most common malignant liver tumor in childhood. As overexpression of the oncogene PLAG1 (pleomorphic adenoma gene 1) is a characteristic phenomenon in HB, we used RNA interference and subsequent miRNA array analysis to identify miR-492 as most strongly influenced by PLAG1. We provide novel experimental evidence that miR-492 can originate from the coding sequence of the HB marker gene keratin 19 (KRT19). In agreement with these in vitro observations, significantly elevated levels of coexpressed KRT19 and miR-492 were particularly found in metastatic HB tumor samples. Stable overexpression of miR-492 in HB cell clones served to identify a broad range of differentially expressed transcripts, including several candidate targets of miR-492 predicted by computational algorithms. Among those the liver enzyme BAAT showed significant association with miR-492 expression in HB tumor samples.

CONCLUSION

A close functional relationship between KRT19 and miR-492 was identified that may play an important role in the progression of malignant embryonal liver tumors. Additionally, miR-492 and its associated targets might serve as new HB biomarkers of clinical utility and could assist to explore targeted therapies, especially in metastatic HB with a poor prognosis.

Outcome of hepatoblastomas treated using the Japanese Study Group for Pediatric Liver Tumor (JPLT) protocol-2: report from the JPLT

BACKGROUND

In the recent years, surgical resection with pre- and/or postoperative chemotherapy has markedly improved the survival rate of hepatoblastoma patients. We herein report the results of patients treated with the current protocol of the Japanese Study Group for Pediatric Liver Tumor, JPLT-2.

METHODS

A total of 279 patients with malignant liver tumor were enrolled in JPLT-2. Data from 212 hepatoblastoma cases were analyzed. PRETEXT I patients were treated with primary resection followed by low doses of cisplatin-pirarubicin (tetrahydropyranyl-adriamycin). Otherwise, patients received preoperative cisplatin-pirarubicin (CITA), followed by surgery and postoperative chemotherapy. Ifosfamide, pirarubicin, etoposide, and carboplatin (ITEC) were given as a salvage treatment. High-dose chemotherapy with hematopoietic stem cell transplantation (SCT) was reserved for patients with metastatic diseases.

RESULTS

The 5-year overall survival rate (OS) in non-metastatic cases was 100% for PRETEXT I, 87.1% for PRETEXT II, 89.7% for PRETEXT III, and 78.3% for PRETEXT IV. The 5-year OS in metastatic cases was 43.9%. The outcome in non-metastatic PRETEXT IV cases was markedly improved, while the results of metastatic tumors remained poor.

CONCLUSIONS

JPLT-2 protocol achieved satisfactory survival among children with non-metastatic hepatoblastoma. New approaches are needed for patients with metastatic diseases.

Inhibition of Bcl-2 and Bcl-X enhances chemotherapy sensitivity in hepatoblastoma cells

BACKGROUND

An increased expression of anti-apoptotic proteins is regularly found in malignant cells, contributing to their clonal expansion by conferring an improved survival ability. In Hepatoblastoma (HB) apoptosis regulation contributes to resistance and therapy failure, therefore we modulated apoptosis sensitivity of HB cells for an improved cytotoxic activity of commonly used drugs.

PROCEDURE

Apoptosis-related proteins were quantified in HB cells (HuH6 and HepT1) using protein assays. Interaction of ABT-737, a small-molecule inhibitor of Bcl-2, Bcl-xL, and Bcl-W with cytotoxic drugs was monitored in a proliferation assay. Apoptosis induction was measured by caspase-3 activity.

RESULTS

We found high levels of the anti-apoptotic protein Bcl-2 and Bcl-X as well as low levels of pro-apoptotic protein Bax and Bad in both HB cell lines. ABT-737 induced apoptosis in HuH6 and HepT1 cells at concentrations higher than 1 µM. ABT-737 also enhanced the cytotoxic effect of cisplatin (CDDP), doxorubicin (DOXO), etoposide and paclitaxel when used as combination therapy. HuH6 expressed slightly higher pro-apoptotic and lower anti-apoptotic protein levels than HepT1, which may explain the stronger enhancement of cytostatic drug effects in HuH6 cells when treated in combination with ABT-737.

CONCLUSION

The observed anti-apoptotic phenotype in HB cell lines may contribute to resistance to cytotoxic drugs used in the standard treatment protocol of HB. These pre-clinical results suggest that apoptosis sensitizers with BH-3 mimicry, such as ABT-737, should be further evaluated in preclinical models of HB.

Genome-wide analysis of allelic imbalances reveals 4q deletions as a poor prognostic factor and MDM4 amplification at 1q32.1 in hepatoblastoma

In a single-nucleotide polymorphism array-based analysis of 56 hepatoblastoma (HB) tumors, allelic imbalances were detected in 37 tumors (66%). Chromosome gains were found in 1q (28 tumors), 2q (24), 6p (8), 8q (8), 17q (6), and 20pq (10), and losses in 1p (6), 4q (9), and 16q (4). Fine mapping delineated the shortest overlapping region (SOR) of gains at 1q32.1 (1.3 Mb) and 2q24.2-q24.3 (4.8 Mb), and losses at 4q34.3-q35.2 (8.7 Mb) and 4q32.3 (1.6 Mb). Uniparental disomy of 11pter-11p15.4 (IGF2) and loss of 11pter-p14.1 were found in 11 and 2 tumors, respectively. Expression of HTATIP2 (11p15.1) was absent in 9 of 20 tumors. Amplification was identified in four tumors at 1q32.1, where the candidate oncogene MDM4 is located. In the 4q32.3-SRO, ANXA10S, a variant of the candidate tumor suppressor ANXA10, showed no expression in 19 of 24 tumors. Sequence analysis of ANXA10S identified a missense mutation (E36K, c.106G>A) in a HB cell line. Multivariate analysis revealed that both 4q deletion and RASSF1A methylation (relative risks: 4.21 and 7.55, respectively) are independent prognostic factors. Our results indicate that allelic imbalances and gene expression patterns provide possible diagnostic and prognostic markers, as well as therapeutic targets in a subset of HB.

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.

Cure of multifocal panhepatic hepatoblastoma: is liver transplantation always necessary?

PURPOSE

Multifocal panhepatic hepatoblastoma (HB) without extrahepatic disease is generally considered as an indication for total hepatectomy and liver transplantation. However, after initial chemotherapy, downstaging of the tumor sometimes allows complete macroscopic resection by partial hepatectomy. This procedure is no longer recommended because of the risk of persistent viable tumor cells in the hepatic remnant. We report our experience with conservative surgery in such cases.

METHOD

Between 2000 and 2005, 4 children were consecutively referred to our unit with multinodular pan-hepatic HBs (classification PRETEXT IV of the International Society of Pediatric Oncology Liver Tumor Study Group SIOPEL). Three of them had extrahepatic disease at diagnosis. All patients were treated according to SIOPEL 3 and 4 protocols.

RESULTS

Extrahepatic metastases were still viable in 2 of 3 patients after initial chemotherapy. These patients eventually died of tumor recurrence. In the 2 patients without residual extrahepatic disease, liver tumors had regressed, and complete macroscopic excision of hepatic tumor remnants could be achieved by conservative surgery. These 2 children are alive and well and free of tumor 7 years after diagnosis.

CONCLUSIONS

Conservative surgery may be curative in some multinodular PRETEXT IV HB patients, with a good response to preoperative chemotherapy and complete excision of all macroscopic tumor remnants. However, because of the lack of reliable predictors of sterilization of the microscopic disease in the residual liver, with subsequent poor prognosis, total hepatectomy and liver transplantation remain currently recommended in patients with multinodular PRETEXT IV HB without extrahepatic disease, even though some of these children are probably overtreated.

Successful treatment of childhood high-risk hepatoblastoma with dose-intensive multiagent chemotherapy and surgery: final results of the SIOPEL-3HR study

PURPOSE

The primary objective was to determine the efficacy of a newly designed preoperative chemotherapy regimen in an attempt to improve the cure rate of children with high-risk hepatoblastoma.

PATIENTS AND METHODS

High risk was defined as follows: tumor in all liver sections (ie, Pretreatment Extension IV [PRETEXT-IV]), or vascular invasion (portal vein [P+], three hepatic veins [V+]), or intra-abdominal extrahepatic extension (E+), or metastatic disease, or alpha-fetoprotein less than 100 ng/mL at diagnosis. Patients were treated with alternating cycles of cisplatin and carboplatin plus doxorubicin (preoperatively, n = 7; postoperatively, n = 3) and delayed tumor resection.

RESULTS

Of the 151 patients (150 evaluable for response) 118 (78.7%) achieved a partial response to chemotherapy. Complete resection of the liver tumor could be achieved in 115 patients (76.2%) either by partial hepatectomy (55.6%) or by liver transplantation (20.6%). In 106 children (70.2%), complete resection of all tumor lesions (including metastases) was achieved. Among the patients with initial lung metastases, 52.2% achieved complete remission of the lung lesions with chemotherapy alone. In half of the patients with initial PRETEXT-IV tumor as the only high-risk feature, the tumor could be completely resected with partial hepatectomy. Event-free (EFS) and overall survival (OS) estimates at 3 years were 65% (95% CI, 57% to 73%) and 69% (95% CI, 62% to 77%) for the whole group. EFS and OS for all patients with PRETEXT-IV tumor were 68% and 69%, respectively, and they were 56% and 62%, respectively, for patients with metastasis.

CONCLUSION

The applied treatment rendered a great proportion of tumors resectable, and, in comparison with previously published results, led to an improved survival in patients with high-risk hepatoblastoma.

MT1G hypermethylation: a potential prognostic marker for hepatoblastoma

Hepatoblastoma comprises only 1% of all cancers in childhood. Because of its low frequency, a small number of prognostic factors are described in hepatoblastoma and most of them are related to resectability. Microarray studies showed a large number of underexpressed genes in hepatoblastoma. Because aberrant DNA methylation has been recognized as an alternative mechanism for tumor suppressor gene inactivation, this could be involved with gene downregulation in these tumors. Despite the rarity of hepatoblastoma, this study evaluated the methylation pattern of 25 genes in 20 paraffin-embedded tumor specimens and five non-neoplastic liver samples (normal control) by quantitative methylation-specific PCR (QMSP). The examination of the methylation profile of hepatoblastoma samples and normal liver specimens revealed a high tumor-specific DNA hypermethylation in the promoter regions of five genes (APC, CDH1, MT1G, RASSF1A, and SOCS1). Furthermore, MT1G hypermethylation showed a significant correlation with poor prognosis of patients with hepatoblastoma. This study represents the first quantitative evaluation of promoter hypermethylation in hepatoblastoma and demonstrated that aberrant methylation is a frequent event in this malignancy. Furthermore, our data provide evidence that MT1G hypermethylation may be useful as prognostic indicator for this disease and suggest that patients with hepatoblastoma may benefit from demethylating drug treatments.

Hepatoblastoma metastatic to the right atrium responding to chemotherapy alone

An 18-month-old boy presented with abdominal pain and distension. On physical examination there was a 10 x 7-cm mass in the right upper abdominal quadrant. His alpha-fetoprotein level was 175,000 IU/mL. Abdominal magnetic resonance findings revealed hepatomegaly with multiple tumor masses involving nearly all the segments of the liver (PRETEXT IV). The tumor extended through the inferior vena cava and filled 2/3 of the right atrium. Echocardiography revealed normal cardiac function. Histopathologic findings after liver biopsy were consistent with hepatoblastoma. After 6 courses of chemotherapy including cisplatin and doxorubicin (PLADO, SIOPEL protocol), the cardiac tumor regressed completely. The patient's primary tumor was then fully resected; no cardiac surgery was performed. After surgery the AFP level was 4 IU/mL and echocardiography revealed normal cardiac function with no residual tumor. The patient has been in remission for 31 months postdiagnosis.

Cisplatin versus cisplatin plus doxorubicin for standard-risk hepatoblastoma

BACKGROUND

Preoperative cisplatin alone may be as effective as cisplatin plus doxorubicin in standard-risk hepatoblastoma (a tumor involving three or fewer sectors of the liver that is associated with an alpha-fetoprotein level of >100 ng per milliliter).

METHODS

Children with standard-risk hepatoblastoma who were younger than 16 years of age were eligible for inclusion in the study. After they received one cycle of cisplatin (80 mg per square meter of body-surface area per 24 hours), we randomly assigned patients to receive cisplatin (every 14 days) or cisplatin plus doxorubicin administered in three preoperative cycles and two postoperative cycles. The primary outcome was the rate of complete resection, and the trial was powered to test the noninferiority of cisplatin alone (<10% difference in the rate of complete resection).

RESULTS

Between June 1998 and December 2006, 126 patients were randomly assigned to receive cisplatin and 129 were randomly assigned to receive cisplatin plus doxorubicin. The rate of complete resection was 95% in the cisplatin-alone group and 93% in the cisplatin-doxorubicin group in the intention-to-treat analysis (difference, 1.4%; 95% confidence interval [CI], -4.1 to 7.0); these rates were 99% and 95%, respectively, in the per-protocol analysis. Three-year event-free survival and overall survival were, respectively, 83% (95% CI, 77 to 90) and 95% (95% CI, 91 to 99) in the cisplatin group, and 85% (95% CI, 79 to 92) and 93% (95% CI, 88 to 98) in the cisplatin-doxorubicin group (median follow-up, 46 months). Acute grade 3 or 4 adverse events were more frequent with combination therapy (74.4% vs. 20.6%).

CONCLUSIONS

As compared with cisplatin plus doxorubicin, cisplatin monotherapy achieved similar rates of complete resection and survival among children with standard-risk hepatoblastoma. Doxorubicin can be safely omitted from the treatment of standard-risk hepatoblastoma. (ClinicalTrials.gov number, NCT00003912.)

Long-term treatment results of hepatoblastoma at a single institution in Taiwan

From 1990 to 2004, there were 23 consecutive patients with hepatoblastoma treated at Mackay Memorial Hospital in Taipei, Taiwan. There were 7 patients of stage I, 3 of stage II, 13 of stage III, and none had stage IV disease. Two siblings had congenital hepatoblastoma and both survived. Two patients were prematurity. Beckwith-Wiedemann syndrome, isosexual precocity, chronic B hepatitis presented in 1 patient each. In addition to surgery, we used cisplatin 90 mg/m/d on day 1 and epirubicin 25 mg/m/d for days 1 to 3 as first-line chemotherapy. Each course was repeated every 3 weeks. Epirubicin was chosen because of its lower cardiotoxicity. Carboplatin/etoposide and vincristine/cyclophosphamide/5-fluorouracil were the second-line chemotherapy for considering cumulative toxicity of first-line chemotherapy. If initial total excision was feasible, postoperative chemotherapy of 4 to 6 courses were given. Three patients died of progressive disease, infection, and relapse 1 each. The median duration of follow-up for 20 survived patients was 94 months. The 5-year event-free and overall survival rates were 73.9%+/-9.2% (SE) and 87%+/-7.0%, respectively. Tumor recurred in 5 patients. The commonest toxicity was febrile neutropenia. There was no cardiotoxicity event. In conclusion, with sequential combination of surgery and chemotherapy, the treatment results for hepatoblastoma were satisfactory as compared with other groups.

Blocking the hedgehog pathway inhibits hepatoblastoma growth

Recent evidence has indicated that Hedgehog (Hh) signaling significantly contributes to liver development and regeneration and that activation of the pathway may contribute to growth of hepatocellular carcinoma (HCC) in adults. However, the role of Hh signaling in pediatric liver tumors remains to be elucidated. In this study, we show that Hh signaling is activated in hepatoblastoma (HB), the most common liver tumor in childhood, with most occurrences before the age of 3 years. The Hh target genes glioma-associated oncogene homolog 1 (GLI1) and Patched (PTCH1) showed increased transcript levels in 65% and 30% of HB samples, respectively, compared with normal liver tissues. Most interestingly, the gene encoding the hedgehog interacting protein (HHIP) is transcriptionally silenced by cytosine-phospho-guanosine (CpG) island promoter hypermethylation in 26% of HB cases and treatment with the DNA-demethylating agent 5-aza-2'-deoxycytidine partially restored HHIP expression. Blocking Hh signaling with the antagonist cyclopamine had a strong inhibitory effect on cell proliferation of HB cell lines with an activated pathway. We further demonstrate that this decrease in cell viability is caused by a massive induction of apoptosis, as shown by morphological changes and phosphatidylserine membrane asymmetry. In cyclopamine-exposed HB cells, caspase 3 and poly(adenosine diphosphate-ribose) polymerase proteins were specifically activated by their proteolytic cleavage.

CONCLUSION

This study demonstrates, for the first time, the frequent occurrence of GLI1 and PTCH1 overexpression and HHIP promoter methylation in early childhood HB, thus indicating a key role for Hh signaling activation in the malignant transformation of embryonal liver cells.

[Clinical characteristics and survival of children with hepatoblastoma--single centre experience]

INTRODUCTION

Hepatoblastoma is the most frequent malignant liver tumour of childhood and it accounts for 1% of all paediatric cancers. The outcome is significantly improved by introducing intensive chemotherapy regimens followed by complete surgical tumour resection. The long-term survival is 75-95% at present.

OBJECTIVE

To summarize clinical characteristics and treatment results in children with hepatoblastoma.

METHOD

The patients diagnosed with hepatoblastoma and treated at the Department of Haematology of the University Children's Hospital in Belgrade, between January 1995 and December 2007 were retrospectively analysed. We analysed mode of therapy, surgical management and patients' survival according to Kaplan Mayer statistical test.

RESULTS

Eleven patients were treated (ten boys and one girl), aged from 6 months to 13 years, mean 32 months, median 12 months. The most frequent presenting sign was abdominal distension. Routine laboratory examination showed elevated alpha-fetoprotein (AFP), range 147 to 44880 ng/ml, mean 8667 ng/ml.Ten patients (91%) had elevated platelet count, range 450 to 909 x 10(9)/l. Initial lung metastasis developed in 3 patients (27%).The diagnosis was established by an open surgical biopsy in 6 patients and after complete tumour resection in 4 patients, namely 2 patients after preoperative chemotherapy and in 2 patients with no previous chemotherapy. Histopathology verified hepatoblastoma in 10 patients: in 7 patients with epithelial type and in 3 patients with mixed epithelial-mesenchyme type. Six patients were in continuous remission with mean follow up of 58 months. One patient was lost to follow up. Four patients died; three patients due to disease progression and one patient due to sepsis after the first cycle of chemotherapy.

CONCLUSION

Combined preoperative chemotherapy with complete tumour resection followed by postoperative chemotherapy results in a high percentage of definitive cures.

Successful treatment of second hepatoblastoma relapse: Case report

Introuduction: The prognosis of hepatoblastoma has changed since effective adjuvant chemotherapy had been introduced in 1980's. There is a general agreement that complete resection is the cornerstone of treatment for children with hepapatoblastoma and the only way for eventual cure. Case report: We describe a boy with relapsed hepatoblastoma presenting with elevated-fetoprotein (AFP) and no visible tumor by ultrasound and computed tomography (CT). The relapse was treated with chemotherapy. Second relapse occurred shortly after therapy was completed, but this time we waited for tumor mass to appear. Combined surgery and chemotherapy resulted in remission status with 48 months of follow up. Conclusion: Hepatoblastoma relapse without evidence of tumor is not unusual but its treatment remains controversial. Radiological investigations should be repeated until site of relapse is identified. Based on our experience it seems of no benefit to treat isolated elevation of AFP.

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.

Loss of imprinting of IGF2 correlates with hypermethylation of the H19 differentially methylated region in hepatoblastoma

IGF2, a maternally imprinted foetal growth factor gene, is implicated in many childhood tumours including hepatoblastoma (HB); however, the genetic and epigenetic alterations have not comprehensively been studied. We analysed the methylation status of the H19 differentially methylated region (DMR), loss of heterozygosity (LOH) and allelic expression of IGF2 in 54 HB tumours, and found that 12 tumours (22%) with LOH, 9 (17%) with loss of imprinting (LOI) and 33 (61%) with retention of imprinting (ROI). Biallelic and monoallelic IGF2 expressions correlated with hypermethylation and normal methylation of H19 DMR, respectively, in two tumours with LOI and seven tumours with ROI. Quantitative RT–PCR analysis showed minimal expression of H19 mRNA and substantial expression of IGF2 mRNA in tumours with LOH or LOI, and substantial expression of both H19 and IGF2 mRNAs in tumours with ROI. Increased IGF2 expression with predominant embryonic P3 transcript was found in the majority of HBs with ROI and foetal livers. In contrast to the earlier reports, our findings suggest that the disruption of the enhancer competition model reported in Wilms' tumour may also occur in HB. Both frequencies of LOH and LOI seem to be lower in HB than in Wilms' tumour, reflecting the different tissue origins.

Differential responsiveness of human hepatoma cells versus normal hepatocytes to TRAIL in combination with either histone deacetylase inhibitors or conventional cytostatics

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising candidate for the treatment of cancer because it elicits cell death in many tumor cells while sparing most normal cells. Liver cancer, however, is largely resistant to TRAIL and, thus, requires sensitization for TRAIL-mediated cytotoxicity. Sensitization may be achieved by cotreatment with chemotherapeutic agents. In this study, we comparatively investigated the treatment efficacy of TRAIL in combination with histone deacetylase inhibitors (HDI) versus TRAIL in combination with conventional cytostatics in the hepatocellular carcinoma cell line HepG2 and in the childhood hepatoblastoma cell line Huh6. We found that TRAIL resistance could be overcome by cotreatment with the HDI vorinostat, sodium butyrate and MS-275, but not by cotreatment with the cytostatics carboplatin and etoposide. However, TRAIL combination treatment bears the risk of sensitizing otherwise TRAIL-resistant normal cells. We thus explored a potential cytotoxic effect of combined HDI/TRAIL treatment in normal hepatocytes: TRAIL in conjunction with HDI did not impose any cytotoxicity on the non-malignant cells. In searching for the determinants of HDI-mediated TRAIL sensitization in hepatoma cells, we observed that HDI treatment did not increase cell-surface expression of proapoptotic TRAIL receptors. Instead, HDI treatment enhanced TRAIL-induced cleavage of Bid. In conclusion, our data suggest that HDI are potent sensitizers to TRAIL in hepatoma cells and that the combination of HDI and TRAIL is selectively active in hepatoma cells without affecting normal hepatocytes, indicating that the combination of HDI and TRAIL may be an effective approach for the treatment of advanced liver cancer.

Liver tumors in children

Malignant liver tumors account for slightly >1% of all pediatric malignancies, with roughly 150 new cases of liver tumors diagnosed in the U.S. annually. The embryonal tumor, hepatoblastoma, accounts for two thirds of malignant liver tumors in children. Other liver malignancies in children include hepatocellular carcinoma, sarcomas, germ cell tumors, and rhabdoid tumors. Benign tumors of the liver in children include vascular tumors, hamartomas, and adenomas. There is an apparent increase in the incidence of hepatoblastoma with perinatal exposures and decreased premature infant mortality as postulated causes for this increased risk. The known causes and associations of liver tumors in children as well as the approaches to diagnosis and treatment of children are discussed in this review article.

The methylation status of RASSF1A promoter predicts responsiveness to chemotherapy and eventual cure in hepatoblastoma patients

Despite the progress of therapy, outcomes of advanced hepatoblastoma patients who are refractory to standard preoperative chemotherapy remain unsatisfactory. To improve the mortality rate, novel prognostic markers are needed for better therapy planning. We examined the methylation status of 13 candidate tumor suppressor genes in 20 hepatoblastoma tumors by conventional methylation-specific PCR (MSP) and found hypermethylation in 3 of the 13 genes. We analyzed the methylation status of these 3 genes (RASSF1A, SOCS1 and CASP8) in 97 tumors and found hypermethylation in 30.9, 33.0 and 15.5%, respectively. Univariate analysis showed that only the methylation status of RASSF1A but not the other 2 genes predicted the outcome, and multivariate analysis showed a weak contribution of RASSF1A methylation to overall survival. Using quantitative MSP, we found RASSF1A methylation in 44.3% of the 97 tumors. CTNNB1 mutation was detected in 67.0% of the 97 tumors. While univariate analysis demonstrated RASSF1A methylation, CTNNB1 mutation and other clinicopathological variables as prognostic factors, multivariate analysis identified RASSF1A methylation (p = 0.043; relative risk 9.39) and the disease stage (p = 0.002; relative risk 7.67) but not CTNNB1 mutation as independent prognostic factors. In survival analysis of 33 patients in stage 3B or 4, patients with unmethylated tumor had better overall survival than those with methylated tumor (p = 0.035). RASSF1A methylation may be a promising molecular-genetic marker to predict the treatment outcome and may be used to stratify patients when clinical trials are carried out.

Impact of pedicle clamping in pediatric liver resection

BACKGROUND

Vascular clamping techniques are commonly used but so far the impact on pediatric liver surgery has not been investigated. The purpose of this study was to analyze pedicle clamping during pediatric liver resection in terms of hepato-cellular injury and blood loss.

METHODS

Sixty-seven children undergoing liver resection were analyzed retrospectively. Vascular clamping was used in 28 cases (PC group), in 39 the resection was performed without clamping (NPC group). Major hepatectomies (resection of more than three segments) were carried out in 88%, minor hepatectomies (resection of three and less segments) in 12% of patients. Twenty-six children underwent extended liver resection. Patient data, liver function tests (LFTs) and blood loss were analyzed statistically.

RESULTS

There were no significant differences in patient preoperative and postoperative data and LFTs between the groups. Within the NPC group the amount of administered fresh frozen plasma (FFP) in total and per kilogram (FFP/kg) was significantly higher (p=0.023 and 0.028) than in the PC group. For patients with extended liver resection, operation times were significantly longer (p=0.016) in the group without vascular clamping (NPCext). In the NPCext group significantly more children required packed red cells, FFP and FFP/kg. LFTs showed no significant differences in all children regardless of vascular clamping.

CONCLUSIONS

For children undergoing liver resection, vascular clamping offers a blood saving surgical technique. Postoperative LFTs were not statistically different, regardless of vascular clamping. Pedicle clamping proved to be a safe method, not associated with an increase in perioperative complications.

Safety of minimal immunosuppression in liver transplantation for hepatoblastoma

BACKGROUND

Despite aggressive chemotherapy, recurrence of disease remains the leading cause of death after liver transplantation (LTx) for hepatoblastoma (HB). Unfortunately, little is known about the effects of immunosuppression on recurrence and posttransplant outcomes. We hypothesized that minimal immunosuppression can be safely used in these recipients.

METHODS

In 2004, we adopted a minimal immunosuppression regimen using daclizumab induction and tacrolimus monotherapy. Kaplan-Meier survival curves were generated.

RESULTS

From 2004 to 2006, 6 children underwent primary LTx for HB with neoadjuvant and adjuvant chemotherapy. Patient survival was 100% at 12 months and at 24 months, without graft loss. One patient died 28 months after transplantation. Recurrence-free survival was 83% at 12 months and at 24 months. Despite minimal immunosuppression (IS), 4 of 6 HB recipients remained rejection-free. When compared to other LTx recipients receiving minimal IS, HB recipients trended to have better rejection-free survival (HB, 83% at 12 months and 62.5% at 24 months vs all others, 36% and 36%, respectively; P = .19).

CONCLUSION

Our short-term patient and graft survival rates are comparable to those reported for all HB recipients in the United Network for Organ Sharing database. Although not statistically significant, our rejection-free survival data suggest that HB recipients may be less likely to reject than other recipients.

Sexual precocity associated with an abdominal tumor in an African boy

We report a 3 year-old boy in Tanzania with an abdominal mass and isosexual precocity due to an hCG-secreting hepatoblastoma. Due to the limited availability of local diagnostic testing, surgery and chemotherapy were completed before immunohistochemical and endocrine results were available.

Hepatoblastoma with a low serum alpha-fetoprotein level at diagnosis: the SIOPEL group experience

AIM OF THE STUDY

To investigate the characteristics of patients with hepatoblastoma and low serum alpha-fetoprotein (AFP) at diagnosis.

PATIENTS AND METHODS

Inclusion of all 21 patients accrued onto SIOPEL trials, whose serum AFP was <100ng/ml at diagnosis. Slides of all 15 patients with available histological material were centrally reviewed.

RESULTS

Median age: 10 months. Disease extension at diagnosis: PRETEXT group: II (3 patients), III (10 patients) and IV (8 patients). Extra-hepatic extension: 8 patients. Multifocal tumour: 8 patients. Histology at review: wholly epithelial subtype: 11/15 patients including nine with a small-cell undifferentiated histology.

OUTCOME

only 9 patients achieved a partial response and 16 died. Median survival: 4.4 months. Two-year overall survival: 24% (confidence interval 10-45%).

CONCLUSION

This study clearly identifies patients with hepatoblastoma and low serum AFP at diagnosis as a high-risk subgroup with extensive disease at diagnosis, poor response to chemotherapy and a poor outcome.

Salvage surgery following downstaging of unresectable hepatocellular carcinoma--a strategy to increase resectability

BACKGROUND

Surgical resection with complete extirpation of the tumor gives the best chance of a cure for patients with hepatocellular carcinoma (HCC). However, the resectability of HCC at the time of diagnosis is low (10-30%). This article reviews the use of salvage surgery following tumor downstaging to treat unresectable HCC.

MATERIALS AND METHODS

A Medline search was undertaken from 1966 to 2005 to identify articles using the keywords "liver neoplasm," "hepatocellular carcinoma," "tumor downstaging," and "unresectable." Additional papers were identified by a manual search of the references from the key articles.

RESULTS

Eight to eighteen percent of patients with unresectable HCC responded well enough to the initial palliative treatment to downstage HCC to allow salvage surgical resection. The reported five-year survival rate after salvage surgery following tumor downstaging varied from 24.9 to 57%.

CONCLUSIONS

Although it is still unknown whether the outcome of salvage surgery following tumor downstaging is comparable to those of resectable tumors after primary resection, one clear message is that salvage surgery following tumor downstaging gives good long-term results and the possibility of a cure in a proportion of patients with unresectable HCC. The role of salvage surgery after tumor downstaging in improving disease-free and overall survival in patients with unresectable HCC should be investigated further by prospective randomized controlled trials.

Promoter hypermethylation of the RASSF1A gene predicts the poor outcome of patients with hepatoblastoma

BACKGROUND

Despite the progress of therapy, about 25% of patients with hepatoblastoma succumb to the disease. Prognostic factors, as well as improved therapies, are needed for these patients. We investigated the incidence and clinical significance of genetic and epigenetic aberrations in hepatoblastoma.

PROCEDURE

beta-catenin mutation was analyzed by sequencing and promoter hypermethylation of the RASSF1A and SFRP genes by methylation-specific PCR after bisulfate treatment of DNA samples from 39 hepatoblastomas. Association of the clinical and biological features, including sex, age of patients, stage of the disease, the histological type, and the beta-catenin and RASSF1A status with overall survival was evaluated using univariate and multivariate analysis.

RESULTS

beta-catenin mutation and RASSF1A methylation were found in 22 (56.4%) and 15 (38.5%) of 39 hepatoblastomas, respectively, but SFRPs methylation was not found in any of them. RASSF1A and SFRPs were unmethylated in five adjacent normal liver tissues. Patients with a RASSF1A methylated tumor were older in age (>or=2 years, P=0.036), at more advanced stages (P=0.009), and had more frequent beta-catenin mutation (P<0.001) and poorer outcome (P<0.001) than those with a RASSF1A unmethylated tumor. While univariate analysis showed the prognostic significance of age, stage, the histological type, and the beta-catenin and RASSF1A status, multivariate analysis showed only the RASSF1A methylation status as an independent factor predicting outcome (relative risk, 10.51; 95% CI, 1.21 approximately 90.97; P=0.033).

CONCLUSIONS

RASSF1A methylation may be a novel molecular-genetic marker for treatment outcome in hepatoblastoma if confirmed by studies examining a larger number of hepatoblastomas.

Tumors of the liver in children

In this review we examine the diagnosis and treatment of pediatric liver tumors- both malignant and benign. The two most common malignant tumors are hepatoblastoma and hepatocellular carcinoma. Hepatoblastoma is seen in younger children, hepatocellular carcinoma in older children. Other malignant liver tumors are quite rare and include biliary rhabdomyosarcoma, angiosarcoma, rhabdoid tumor, and undifferentiated sarcoma. The commonly seen benign liver tumors in children are infantile hemangioma, mesenchymal hamartoma, and focal nodular hyperplasia. Rare benign tumors are hepatic adenoma, which is occasionally seen in teenage girls, and teratoma which is a very rare liver tumor in infants.

Treatment outcomes for hepatoblastoma: an institution's experience over two decades

Our objective is to review a leading Australian tertiary referral centre's experience in treating hepatoblastoma over two decades. This is a retrospective study of clinical, radiological and pathological data in hepatoblastoma patients treated at our institution between 1984 and 2004. Thirty children (17 male, 13 female) ranging in age from 5 months to 6.5 years (median 19 months) at diagnosis were reviewed. This is the largest case series reported in Australia to date. The median length of follow-up was 6.3 years (range 7 months to 20.9 years). On average, the number of new cases increased by 0.12 each year (P=0.01). A total of 29 patients underwent definitive surgery for primary tumour control. Of these, two (7%) had initial primary surgery, while 27 (93%) had delayed surgery following neo-adjuvant chemotherapy. Chemotherapy regimens included the SIOPEL study protocols. Patients not enrolled in SIOPEL tended to be given more courses of chemotherapy. Ten patients (34%) received an extended right hemi-hepatectomy, six (21%) had right hemi-hepatectomy, seven (24%) had left hemi-hepatectomy, three (10%) had left lateral segmentectomy, and two (7%) had a non-anatomical resection. In addition, two patients required IVC reconstruction at the time of their primary liver resection. Overall survival at 5 years was 89.1% (95% CI 69.8-96.4%). Event-free survival at 5 years was 75.7% (95% CI 53.2-88.5%). There was a clear increase in the risk of recurrence (RR=4.8) and death (RR=4.5) where margins were not microscopically clear. However, neither reached statistical significance in this small cohort. Surgery was still worthwhile even when margins were involved. There was no correlation between mean AFP level at diagnosis, and outcome. Our experience suggests that the achievement of microscopically clear margins at the time of primary tumour resection is an important factor in achieving a positive long-term outcome. In addition, extended courses of neo-adjuvant chemotherapy in patients with pulmonary metastases achieves good long-term outcomes, provided adequate surgical resection of the primary tumour with clear microscopic margins can be achieved.

Should children at risk for familial adenomatous polyposis be screened for hepatoblastoma and children with apparently sporadic hepatoblastoma be screened for APC germline mutations?

BACKGROUND

Hepatoblastoma (HB) is the most frequent liver tumor in childhood, occurring in the first few years of life. Surgery combined with chemotherapy has resulted in dramatic improvements in prognosis. However, even today, about one quarter of affected children do not survive the disease. Compared to the general population, the risk of HB is 750-7,500 times higher in children predisposed to familial adenomatous polyposis (FAP), an autosomal-dominant cancer predispostion syndrome caused by germline mutations in the tumor suppressor gene APC. Only limited data exist about the frequency of APC germline mutations in cases of apparently sporadic HB without a family history of FAP.

PROCEDURE

In our sample of 1,166 German FAP families, all known cases of HB were registered. In addition, 50 patients with apparently sporadic HB were examined for APC germline mutations.

RESULTS

In the FAP families, seven unrelated cases of HB are documented; three had been detected at an advanced stage. In patients with apparently sporadic HB, germline mutations in the APC gene were identified in 10%.

CONCLUSIONS

These data raise the issue of the appropriate screening for HB in children of FAP patients. To date, the efficiency of surveillance for HB is unclear. In Beckwith-Wiedemann syndrome (BWS), recent studies suggest an earlier detection of both Wilms tumor and HB by frequent screening. We discuss the rationale and implications of a screening program; besides the examination procedure itself, screening for HB in children of FAP patients would have important consequences for the policy of predictive testing in FAP. In a substantial fraction of sporadic HB, the disease is obviously the first manifestation of a de novo FAP. These patients should be identified by routine APC mutation screening and undergo colorectal surveillance thereafter.

Liver cancer in European children: Incidence and survival, 1978–1997. Report from the Automated Childhood Cancer Information System project

Data on 849 children diagnosed with malignant hepatic tumours (International Classification of Childhood Cancer, Group VII) before the age of 15 years during 1978-1997 in Europe were extracted from the ACCIS database. Age-standardised incidence during 1988-1997 was 1.5 per million overall, 1.2 per million for hepatoblastoma and 0.2 per million for hepatic carcinoma. Over 90% of cases of hepatoblastoma occurred before age 5 years, whereas hepatic carcinoma had a fairly flat age distribution. Both tumours had an incidence in boys of 1.5-1.6 times that in girls. There were no significant time trends in incidence during 1978-1997. Five-year survival from hepatoblastoma diagnosed during 1988-1997 was 63% overall, and ranged from 52% in Eastern Europe to 84% in the North. Survival from hepatic carcinoma was much lower (37%). Between 1978-1982 and 1993-1997, 5-year survival (95% confidence interval (95% CI)) increased from 28% (95% CI 18-39) to 66% (95% CI 55-74) for hepatoblastoma and from 17% (95% CI 6-33) to 50% (95% CI 26-70) for hepatic carcinoma. These increases reflect the impact of advances in treatment of childhood liver cancer at a population level.

Optimizing vector application for gene transfer into human hepatoblastoma cells

Gene targeting is currently of distinct interest as an innovative additive treatment option in various malignancies. Its role in pediatric liver tumors has not yet been evaluated thoroughly. For the first time the authors systematically analyzed both lipid-based transfection as well as transduction with adenovirus vectors (Ad) and Sendai virus vectors (SeVV) in order to optimize gene transfer into hepatoblastoma (HB) cells. Two HB cell lines were infected with Ad or SeVV coding for green fluorescent protein (Ad-GFP, SeVV-GFP); transduction efficiencies and apoptosis were assessed using flow cytometry. Furthermore, lipofection of HB cell lines with plasmid-constructs comprising liver-specific promoters was performed using Lipofectamine 2000 and FuGENE 6; lipofection efficiency was monitored by flow cytometry, microscopy, and luciferase activity. The Ad-GFP showed higher transduction rates (61-86%) than the SeVV-GFP (4-24%) depending on the HB cell line used. Infections with first generation SeVV vectors (SeVV-GFP) led to increased target cell apoptosis (7-43%) compared to Ad-GFP (4-16%). The Lipofectamine 2000 revealed a higher transfection efficiency than the FuGENE 6 for both HB cell lines tested. The liver-specific promoters were found to be differently active in the HB cell lines. This study delineates recombinant adenovirus vectors as a promising tool for gene transduction in the HB cells. Furthermore, enhanced activity of the liver-specific promoters in HUH6 cells compared to HepT1 cells supports the observation of varying biological behavior in histologically differing HB tissues.

Intensified platinum therapy is an ineffective strategy for improving outcome in pediatric patients with advanced hepatoblastoma

PURPOSE

The INT-0098 Intergroup Liver Tumor Study demonstrated no statistically significant differences in event-free and overall survival between patients randomized to treatment with either cisplatin + fluorouracil + vincristine (C5V) or cisplatin + doxorubicin. Results from this and other therapeutic trials suggested that cisplatin was the most active agent against hepatoblastoma. To increase the platinum dose-intensity, a novel regimen was developed alternating carboplatin and cisplatin (CC) every 2 weeks. The P9645 study was designed to compare the risk of treatment failure for patients with stage III/IV hepatoblastoma randomized to either C5V or CC.

METHODS

C5V was given according to INT-0098 and CC consisted of carboplatin at 700 mg/m2 on day 0 (560 mg/m2 after two cycles) followed by cisplatin 100 mg/m2 on day 14. Granulocyte colony-stimulating factor was used after each CC cycle. All patients received four to six cycles of chemotherapy.

RESULTS

From the time the study was opened until the time that random assignment was halted, 56 patients received CC and 53 patients received C5V. The 1-year event-free survival was 37% for patients receiving CC and 57% for those receiving C5V (P = .017). Patients randomly assigned to CC required more blood product support. As a result of a semiannual review by the Children's Oncology Group Data and Safety Monitoring Committee, random assignment was discontinued after 3 years of enrollment because the projected improvement in long-term outcome associated with CC was statistically excluded as a possible outcome of this trial.

CONCLUSION

Intensification of therapy by alternating platinum analogs increased the risk of adverse outcome in children with unresectable or metastatic hepatoblastoma.

Unresectable multifocal hepatoblastoma with cardiac extension: excellent response with HB-94 chemotherapy protocol

A 10-month-old white infant presented with abdominal distention and bilateral scrotal hernia. Imaging studies of the abdomen and thorax showed a huge liver with multiple tumor masses and calcification involving all the segments. There was thrombosis in the inferior vena cava and right atrium. alpha-Fetoprotein was 246,000 IU/mL. HB-94 chemotherapy protocol was started at once due to rapid deterioration of the patient. Surgical biopsy performed after the first IPA (ifosfamide, cisplatin, doxorubicin) course showed hepatoblastoma with macrotrabecular variant. After a second IPA course and 2 courses of carboplatin and etoposide, the boy's clinical condition was excellent with normal alpha-fetoprotein but minimal regression and increased calcification in the tumor mass. Hepatic tumor was unresectable and no surgical intervention was performed. Transplantation could not be performed because of high morbidity and mortality. Despite general agreement that complete surgical resection is the cornerstone of treatment for patients with hepatoblastoma, the patient is in remission with 100% Karnofsky score in the 43 months of diagnosis.

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.

Living and deceased donor liver transplantation for unresectable hepatoblastoma at a single center

Hepatoblastoma (HB) is the most common malignant liver tumor in children. The application of living donor liver transplantation (LDLT) in the management of unresectable HB may add new therapeutic opportunities. We evaluated the outcomes of patients who underwent liver transplantation for treatment of unresectable HB in the period between August 1985 and June 2003. Ten children had a diagnosis of unresectable HB. Mean age at transplantation was 5.8 yr. Eight patients were transplanted with deceased donor grafts. Two patients underwent LDLT. Pre-transplant chemotherapy was used in 90% of cases. Post-transplant survival ranges from 3.7 to 18.6 yr. Three patients died of recurrent disease at 4, 14 and 38 months. The two LDLT recipients were able to get pre-transplant chemotherapy with a rapid decision towards transplantation; both are alive and well at 5.5 and 11 yr post-transplant. Our experience supports the role of LDLT and deceased donor liver transplantation in the management of unresectable HB when waiting times can be detrimental to the patient's survival.

Liver transplantation for childhood hepatic malignancy: a review of the United Network for Organ Sharing (UNOS) database

BACKGROUND

Orthotopic liver transplantation (OLT) is the only treatment option for unresectable hepatoblastoma (HB) and hepatocellular carcinoma (HCC) in children. Aggregated outcomes of OLT for these hepatic malignancies have not been evaluated in the United Network for Organ Sharing national database.

PURPOSE

The purpose of this study was to evaluate graft and patient survival in pediatric OLT recipients with HB and HCC.

METHODS

Data from the United Network for Organ Sharing Standard Transplant and Research Files were analyzed and included pediatric (<18 years) OLT recipients with HB or HCC from 1987 to 2004. The effects of diagnosis on pretransplant variables were evaluated using analysis of variance methods or chi2 tests, as appropriate. Actuarial survival and effect of diagnosis on survival were determined using Kaplan-Meier methods and log-rank tests.

RESULTS

Since 1987, 152 OLTs have been performed in 135 pediatric patients for HB and 43 OLTs in 41 pediatric patients for HCC. Respective 1-, 5-, and 10-year patient survival after OLT was 79%, 69%, and 66% for HB and 86%, 63%, and 58% for HCC (P = .73). The primary cause of death for both groups was metastatic or recurrent disease, accounting for 54% of deaths in the HB group and 86% in the HCC group (P = .338). Patients with hepatoblastoma were younger (mean age, 2.9 +/- 2.5 vs 10.4 +/- 4.8 years for the HCC group; P < .001) and more likely to receive a living donor organ (16% vs 4%, P = .03). A greater proportion of the patients with HB had previous abdominal surgery than patients with HCC (63% HB vs 37% HCC, P = .04). Pretransplant medical condition and transplant era were associated with graft and patient survival on univariate and multivariate analysis (all P < .05).

CONCLUSIONS

Orthotopic liver transplantation remains a viable option for pediatric patients with unresectable primary hepatic malignancies and results in good long-term survival. Pretransplant medical condition is an important predictor of outcome. Thus, in conjunction with better chemotherapy regimens, earlier evaluation for OLT in patients with unresectable HB and HCC may result in yet further improved long-term survival.

In vitro gene targeting in human hepatoblastoma

Poor treatment results in advanced hepatoblastoma (HB) made alternative treatment approaches desirable. Gene-directed tumor therapy is increasingly investigated in different malignancies. The aim of this study was to analyze possible alternatives of gene transfer into HB cells and to study therapeutic applications based on different strategies. Liposomal transfection of HB cells was assessed using liver-specific promoters, and adenovirus and Sendai virus transductions were performed in vitro. Transfer efficiencies were measured via flow cytometry determining expression of vector-encoded marker gene green fluorescent protein. Gene silencing of the anti-apoptotic bcl-2 gene in HUH6 cells was performed using lipofection of small interfering RNA (siRNA). Additionally, suicide gene therapy was carried out through a yeast-derived cytosine deaminase (YCD)-combined yeast uracil phosphoribosyltransferase (YUPRT)-based adenovirus-mediated gene transfer, leading to a potent intracellular prodrug transformation of 5-fluorocytosine into 5-fluorouracil. Treatment efficiencies were monitored via MTT viability assay. Highest gene transfer rates (86%) were observed using adenovirus transduction. We furthermore observed a significant therapeutic effect of adenovirus-mediated YCD::YUPRT suicide gene transfer. Liposomal-mediated anti-bcl-2 siRNA transfer led to a significant improvement of cisplatin treatment in HUH6 cells. Liver-specific promoters were found to be strongly active in HUH6 cells (mixed HB-derived), but less active in HepT1 cells (embryonal HB-derived). Liposomal transfection and viral transduction are effective approaches to genetically manipulate HB cells in vitro. For the first time, we demonstrate a positive effect of siRNA gene silencing in this malignancy. Additionally, we successfully investigated a model of adenovirus-based suicide gene therapy in HB cell cultures. Our data strongly encourage further studies assessing these alternative treatment approaches.

Hepatoblastoma in a child with progressive familial intrahepatic cholestasis

End-stage liver cirrhosis because of metabolic or infectious diseases predisposes to hepatic malignancies like hepatocellular carcinoma. We report the first case of hepatoblastoma incidentally detected in the explanted liver of a 2-yr-old child undergoing liver transplantation for cirrhosis because of progressive familial intrahepatic cholestasis (PFIC). The diagnosis was difficult to obtain. The hepatoblastoma was not seen on ultrasound examination of the cirrhotic liver. As we could confirm retrospectively, alpha fetoprotein (AFP) was found elevated prior to transplantation. Two years after successful transplantation, there are no signs of malignancy detectable by clinical and radiological methods. We conclude from this case that PFIC may induce hepatoblastoma and that children with liver cirrhosis should undergo routine screening of serum AFP concentration.

Recurrent hepatoblastoma with localization by PET-CT

Hepatoblastoma is the most common primary liver tumor in children, accounting for 79% of pediatric liver malignancies in children younger than 15 years, with most cases reported before the age of 5 years. Localization of primary and recurrent disease is necessary for appropriate clinical decision-making and treatment. We present a case of recurrent hepatoblastoma heralded by rising alpha-fetoprotein levels. After unsuccessful localization by conventional CT and MRI, positron emission tomography CT imaging localized the sites of recurrence.

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.

Videoscopic fluorescence diagnosis of peritoneal and thoracic metastases from human hepatoblastoma in nude rats

BACKGROUND

Various medical disciplines are employing photodynamic diagnosis (PDD) when searching for malignancies. It is still unknown whether pediatric solid tumors such as hepatoblastoma are susceptible to this technique as well.

METHODS

Human hepatoblastoma cells were injected into the abdomen or right thoracic cavity of nude rats. Tumor growth was allowed for 7 weeks. Then, photosensitization was induced by peritoneal lavage with 5-aminolevulinic acid (ALA). Applying the Storz PDD system and one 4-mm scope, all animals were investigated by videoscopic white light diagnosis (WD) and PDD. Suspicious lesions were marked and analyzed by spectrometry and histology.

RESULTS

Positive fluorescence was documented for every tumor seen by WD in the abdomen or right thoracic cavity. Spectrometry of lesions showed a 6.34-fold increased fluorescence intensity. Histology revealed hepatoblastoma in all specimens.

CONCLUSIONS

Human hepatoblastoma can be detected by PDD in a rat model. Considering the clinical success of this method in other specialties, our findings indicate that further investigations to evaluate the benefit of PDD for children with hepatoblastoma should be performed.

Liver transplantation for hepatoblastoma: indications and contraindications in the modern era

In the past 20 yr, a dramatic improvement has been achieved in the outcome of children with hepatoblastoma by combining cisplatin based chemotherapy and surgery. Treatment of patients in the USA is an exception to the rule that all patients should receive neoadjuvant chemotherapy. It is paramount that surgical resection be complete, both macro- and microscopically. Complete tumor resection can be achieved after chemotherapy with a partial hepatectomy when the intrahepatic extent is limited to 1-3 sectors. In multifocal (and solitary) hepatoblastomas invading all four liver sectors, and in centrally located tumors with close proximity to the major veins, the SIOPEL-1 study and an extensive review of the world experience have shown that primary transplantation provides high, long term, disease-free survival rate in the range of 80%. In contrast, the results of rescue transplants for incomplete tumor resection or disease recurrence after partial hepatectomy are disappointing (in the range of 30%). Hazardous attempts at partial hepatectomy in children with extensive hepatoblastoma should be discouraged. Guidelines are provided for early referral of children with extended hepatoblastoma to a transplant surgeon. There is a trend for a better patient survival after living related liver transplantation. Patients who will become candidates to liver transplantation should be treated with chemotherapy following the same protocols as for children undergoing a partial hepatectomy. There is a concern about cumulative nephrotoxicity of calcineurin inhibitors and chemotherapeutic drugs. Recent data suggest that these patients tolerate lower Tacrolimus trough blood levels than those transplanted for non-malignant conditions, without increasing the risk of acute rejection. Due to the rarity of the disease, these children should be treated in specialized centers.