Hepatoblastoma--evolution of management and outcome and significance of histology of the resected tumor. A 31-year experience with 40 cases

IMPDH2 suppression impedes cell proliferation by instigating cell cycle arrest and stimulates apoptosis in pediatric hepatoblastoma

BACKGROUND

Hepatoblastoma (HB) is the most common pediatric liver tumor, presenting significant therapeutic challenges due to its high rates of recurrence and metastasis. While Inosine Monophosphate Dehydrogenase 2(IMPDH2) has been associated with cancer progression, its specific role and clinical implications in HB have not been fully elucidated.

METHODS

This study utilized Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and Tissue Microarray (TMA) for validation. Following this, IMPDH2 was suppressed, and a series of in vitro assays were conducted. Flow cytometry was employed to assess apoptosis and cell cycle arrest. Additionally, the study explored the synergistic therapeutic effects of mycophenolate mofetil (MMF) and doxorubicin (DOX) on HB cell lines.

RESULTS

The study identified a marked overexpression of IMPDH2 in HB tissues, which was strongly correlated with reduced Overall Survival (OS) and Event-Free Survival (EFS). IMPDH2 upregulation was also found to be associated with key clinical-pathological features, including pre-chemotherapy alpha-fetoprotein (AFP) levels, presence of preoperative metastasis, and the pre-treatment extent of tumor (PRETEXT) staging system. Knockdown of IMPDH2 significantly inhibited HB cell proliferation and tumorigenicity, inducing cell cycle arrest at the G0/G1 phase. Notably, the combination of MMF, identified as a specific IMPDH2 inhibitor, with DOX, substantially enhanced the therapeutic response.

CONCLUSION

The overexpression of IMPDH2 was closely linked to adverse outcomes in HB patients and appeared to accelerate cell cycle progression. These findings suggest that IMPDH2 may serve as a valuable prognostic indicator and a potential therapeutic target for HB.

IMPACT

The present study unveiled a significant overexpression of inosine monophosphate dehydrogenase 2 (IMPDH2) in hepatoblastoma (HB) tissues, particularly in association with metastasis and recurrence of the disease. The pronounced upregulation of IMPDH2 was found to be intimately correlated with adverse outcomes in HB patients. This overexpression appears to accelerate the progression of the cell cycle, suggesting that IMPDH2 may serve as a promising candidate for both a prognostic marker and a therapeutic target in the context of HB.

Evaluation of the diagnostic biopsy approach for children with hepatoblastoma: A report from the children's oncology group AHEP 0731 liver tumor committee

BACKGROUND

The histopathological assessment of pediatric liver tumors at presentation is critical to establish a diagnosis, guide treatment, and collect appropriate research samples. The purpose of this study was to evaluate complications associated with different approaches to liver biopsy for newly diagnosed hepatoblastoma.

METHODS

Children with hepatoblastoma were enrolled on Children's Oncology Group study AHEP0731 (September 2009-March 2012). This analysis evaluated the study cohort of initially unresectable patients who therefore underwent a biopsy procedure at diagnosis. The primary endpoint was clinically significant postbiopsy hemorrhage, defined as requiring red blood cell transfusion.

RESULTS

We identified 121 children who underwent open (n = 76, 63%), laparoscopic (n = 17, 14%), or percutaneous (n = 28, 23%) liver biopsies. All biopsy procedures yielded adequate tissue for diagnosis. Postbiopsy hemorrhage requiring transfusion occurred after 26% (n = 31) of biopsies. Need for blood product transfusion most frequently occurred following open (n = 27/76, 36%) and laparoscopic (n = 4/17, 24%) biopsies, compared with percutaneous (n = 0/28, 0%) biopsies (p < 0.01).

CONCLUSIONS

Pretreatment biopsy of pediatric liver tumors via a percutaneous approach yielded the lowest frequency of clinically significant hemorrhage requiring transfusion, without evidence of sacrificing diagnostic accuracy.

LEVEL OF EVIDENCE

Level I.

LIN28B gene polymorphisms modify hepatoblastoma susceptibility in Chinese children

Hepatoblastoma is one of the malignant liver tumors in children. However, genetic mechanisms underpinning the initiation of hepatoblastoma remain largely unclear. The previous study showed that lin-28 homolog B (LIN28B) might play a role in the development of hepatoblastoma. To detect the association between LIN28B gene polymorphisms and hepatoblastoma risk in Chinese children, we conducted a five-center case-control study of 275 hepatoblastoma patients and 1018 cancer-free controls. Four potentially functional polymorphisms were genotyped using the Taqman method. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the strength of the associations. We found that the rs314276 C>A polymorphism (AA vs. CC: adjusted OR=2.05, 95% CI=1.36-3.10, P=0.0006; AA vs. CA/CC: adjusted OR=2.11, 95% CI=1.43-3.12, P=0.0002) and rs9404590 T>G (GG vs. TT: adjusted OR=1.89, 95% CI=1.20-3.00, P=0.007; GG vs. TT/TG: adjusted OR=1.87, 95% CI=1.20-2.92, P=0.006) were associated with increased hepatoblastoma risk. Combination analysis of risk genotypes showed that patients with four risk genotypes had a higher chance of developing hepatoblastoma than carriers of 1 to 3 risk genotypes. Stratification analysis showed the significant association between the rs314276 AA genotype and hepatoblastoma risk in both age and sex groups, as well as clinical stages III+IV cases. The rs9404590 GG genotype was associated with hepatoblastoma risk in participants' ≥17 months, in females, and for those with clinical stages III+IV disease. Furthermore, four risk genotypes confer higher hepatoblastoma susceptibility in both age and sex groups, as well as groups with clinical stages III+IV disease. Genotype-based gene expression analysis confirmed that the rs9404590 T>G polymorphism was significantly associated with altered LIN28B gene expression. We further validated our findings using false-positive probability analysis. This finding suggested that LIN28B gene polymorphisms may be associated with an increased predisposition to hepatoblastoma.

The Emerging Roles of Cancer Stem Cells and Wnt/Beta-Catenin Signaling in Hepatoblastoma

Hepatoblastoma (HB) is the most common form of primary liver malignancy found in pediatric populations. HB is considered to be clonal and arises from hepatoblasts, or embryonic liver progenitor cells. These less differentiated tumor-initiating progenitor cells, or cancer stem cells (CSCs), may contribute to tumor recurrence and resistance to therapies, and have high metastatic abilities. Phenotypic heterogeneity, undesired genetic and epigenetic alterations, and dysregulated signaling pathways provide CSCs with a survival advantage over current therapies. The molecular and cellular basis of HB and the mechanism of CSC induction are not fully understood. The Wnt/beta-catenin pathway is one of the major developmental pathways and is believed to play an important role in the pathogenesis of HB and CSC formation. This review summarizes the cellular and molecular characteristics of HB with a specific emphasis on CSCs and Wnt/beta-catenin signaling.

Periostin mediates epithelial-mesenchymal transition through the MAPK/ERK pathway in hepatoblastoma

Objective

The aim of the present study was to analyze the prognostic factors in patients with hepatoblastoma (HB) in our single center and to evaluate periostin (POSTN) expression in HB and its association with clinicopathological variables. In addition, the underlying mechanism of how POSTN promotes HB progression was discussed.

Methods

POSTN expression was investigated in HB tumors by immunohistochemistry (IHC), immunofluorescence (IF) and Western blot (WB). The association among POSTN expression, clinicopathological features and overall survival (OS) was also evaluated. The migration and adhesion ability of HB cells were measured using chemotaxis and cell-matrix adhesion assays, respectively. Epithelial-mesenchymal transition (EMT)-associated markers and activation of the ERK pathway were detected by WB.

Results

HB patients had poor prognosis which displayed lymph node metastasis, vascular invasion, POSTN and vimentin expression. POSTN expression was also associated with lymph node metastasis. Furthermore, overexpressed POSTN promoted migration and the adhesive ability of HB cells in vitro. In addition, we demonstrated that POSTN activated the MAPK/ERK pathway, upregulated the expression of Snail and decreased the expression of OVOL2. Finally, POSTN promoted the expression of EMT-associated markers.

Conclusions

POSTN might modulate EMT via the ERK signaling pathway, thereby promoting cellular migration and invasion. Our study also suggests that POSTN may serve as a therapeutic biomarker in HB patients.

Novel Advances in Understanding of Molecular Pathogenesis of Hepatoblastoma: A Wnt/β-Catenin Perspective

Hepatoblastoma is the most common pediatric liver malignancy, typically striking children within the first 3 years of their young lives. While advances in chemotherapy and newer surgical techniques have improved survival in patients with localized disease, unfortunately, for the 25% of patients with metastasis, the overall survival remains poor. These tumors, which are thought to arise from hepatic progenitors or hepatoblasts, hence the name hepatoblastoma, can be categorized by histological subtyping based on their level of cell differentiation. Genomic and histological analysis of human tumor samples has shown exon-3 deletions or missense mutations in gene coding for β-catenin, a downstream effector of the Wnt signaling pathway, in up to 90% of hepatoblastoma cases. The current article will review key aberrations in molecular pathways that are implicated in various subtypes of hepatoblastoma with an emphasis on Wnt signaling. It will also discuss cooperation among components of pathways such as β-catenin and Yes-associated protein in cancer development. Understanding the complex network of molecular signaling in oncogenesis will undoubtedly aid in the discovery of new therapeutics to help combat hepatoblastoma.

New concepts and outcomes for children with hepatoblastoma based on the experience of a tertiary center over the last 21 years

OBJECTIVE

The aim of this study was to summarize the experience of a tertiary center in treating hepatoblastoma for the last 21 years.

PATIENTS AND METHODS

Fifty-eight cases were included. The tumor extent and prognosis were assessed using the PRETEXT system. The following data were analyzed: age at diagnosis, comorbidities, prematurity, treatment modalities, histopathological findings, surgical details and complications, treatment outcomes, chemotherapy schedules, side effects and complications. Treatment outcomes included the occurrence of local or distant recurrence, the duration of survival and the cause of death. The investigation methods were ultrasonography, CT scan, serum alpha-fetoprotein level measurement and needle biopsy. Chemotherapy was then planned, and the resectability of the tumor was reevaluated via another CT scan.

RESULTS

The mean numbers of neoadjuvant cycles and postoperative cycles of chemotherapy were 6±2 and 1.5±1.7, respectively. All children except one were submitted for surgical resection, including 50 partial liver resections and 7 liver transplantations. Statistical comparisons demonstrated that long-term survival was associated with the absence of metastasis (p=0.04) and the type of surgery (resection resulted in a better outcome than transplantation) (p=0.009). No associations were found between vascular invasion, incomplete resection, histological subtype, multicentricity and survival. The overall 5-year survival rate of the operated cases was 87.7%.

CONCLUSION

In conclusion, the experience of a Brazilian tertiary center in the management of hepatoblastoma in children demonstrates that long survival is associated with the absence of metastasis and the type of surgery. A multidisciplinary treatment involving chemotherapy, surgical resection and liver transplantation (including transplantations using tissue from living donors) led to good outcomes and survival indexes.

Role of liver transplantation in the management of hepatoblastoma in the pediatric population

Hepatoblastoma (HB) is the most common primary liver tumor in children and accounts for two-thirds of all malignant liver neoplasms in the pediatric population. For patients with advanced HB (unresectable or unresponsive to chemotherapy), combined treatment with chemotherapy and liver transplantation is an excellent option. The etiology of HB is mostly obscure because of its extreme rarity although some inherited syndromes and very low birth weight have been associated with it. The prognosis for children with HB has significantly improved in the past three decades thanks to advancements in chemotherapy, surgical resection and postoperative care. In 2002 a surgical staging system called pretreatment extent of disease (PRETEXT) was designed to allow a universal, multidisciplinary approach to patients with HB. Between one-third to two-thirds of patients initially present with unresectable tumors or distant metastases, but up to 85% of these tumors become operable after neoadjuvant chemotherapy. Patients with PRETEXT categories 1, 2, and some 3 are referred for neoadjuvant chemotherapy followed by surgical resection with the goal of complete tumor removal. Classic treatments regimens include a combination of cisplatin, fluorouracil, and vincristine or cisplatin and doxorubicin. Liver transplantation is the only treatment option for unresectable HB. In 2010 the pediatric end-stage liver disease, a pediatric-specific scoring system that determines a patient’s ranking on the liver transplant list, began to award additional “exception” points for patients with HB. We analyzed the Standard Transplant Analysis and Research dataset to assess the impact of changes in exception point criteria for HB on outcomes after liver transplantation at Texas Children’s Hospital in Houston, Texas. We found that patients who were listed for transplantation with current HB exception criteria experienced a shorter waitlist time but survival was similar between the two eras.

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

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

Needle tract implantation of hepatoblastoma after percutaneous needle biopsy: report of a case

A 13-year-old boy was referred to us for investigation of a giant liver mass, approximately 16 cm in diameter. Sonographically guided percutaneous needle biopsy was performed and histological examination revealed a fetal-type hepatoblastoma. After four courses of chemotherapy, we performed a left hepatic trisegmentectomy. Follow-up computed tomography, 55 months after the surgery, showed a 1-cm tumor on the route of the preoperative needle biopsy. A second laparotomy revealed a peritonealised tumor, which was excised. The histology of this tumor was identical to that of the primary hepatoblastoma. To our knowledge, this is only the second report of needle tract implantation of hepatoblastoma after percutaneous needle biopsy.

FAK Inhibition Decreases Hepatoblastoma Survival Both In Vitro and In Vivo

Hepatoblastoma is the most frequently diagnosed liver tumor of childhood, and children with advanced, metastatic or relapsed disease have a disease-free survival rate under 50%. Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase that is important in many facets of tumor development and progression. FAK has been found in other pediatric solid tumors and in adult hepatocellular carcinoma, leading us to hypothesize that FAK would be present in hepatoblastoma and would impact its cellular survival. In the current study, we showed that FAK was present and phosphorylated in human hepatoblastoma tumor specimens. We also examined the effects of FAK inhibition upon hepatoblastoma cells using a number of parallel approaches to block FAK including RNAi and small molecule FAK inhibitors. FAK inhibition resulted in decreased cellular survival, invasion, and migration and increased apoptosis. Further, small molecule inhibition of FAK led to decreased tumor growth in a nude mouse xenograft model of hepatoblastoma. The findings from this study will help to further our understanding of the regulation of hepatoblastoma tumorigenesis and may provide desperately needed novel therapeutic strategies and targets for aggressive, recurrent, or metastatic hepatoblastomas.

Treatment outcomes for hepatoblastoma: experience of 35 cases at a single institution

BACKGROUND/PURPOSE

Hepatoblastoma is the most common malignant liver tumor in children. Comparative studies have elucidated the optimal pre- or postoperative chemotherapeutic regimens. The aim of this study was to investigate the prognostic significance of baseline tumor characteristics for overall survival and disease-free survival in children with hepatoblastoma.

METHODS

There were 19 male and 16 female children with a median age of 19 months at diagnosis (range: 1-169 months) in our institution between February 1990 and June 2009. We reviewed the clinical presentation, serum α-fetoprotein level at diagnosis, histological subtype, treatment, and outcomes.

RESULTS

Twenty-seven patients (78%) underwent neoadjuvant chemotherapy. The majority of patients subsequently underwent either hemihepatectomy (56%) or bisegmentectomy (16%). Only six patients underwent extended hepatic resection, and one of them required rescue liver transplantation. During follow-up, six patients died of progressive disease and two of perioperative mortality. Four of the six who died had pulmonary metastases at the time of diagnosis or follow-up. The median survival time was 28 months (range: 1-181 months). Five-year overall survival was 67.7% (95% confidence interval: 52.0-87.8%) and disease-free survival was 60.2% (95% confidence interval: 41.9-86.5%).

CONCLUSION

The potential down-staging effect of neoadjuvant chemotherapy on hepatoblastoma might facilitate remission and convert unresectable tumors into operable ones.

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

BACKGROUND

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

PROCEDURE

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

RESULTS

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

CONCLUSIONS

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

Fibrolamellar carcinoma of the liver exhibits immunohistochemical evidence of both hepatocyte and bile duct differentiation

Fibrolamellar carcinoma is a rare malignant primary liver neoplasm with characteristic histological features that typically arises in young patients without viral hepatitis or cirrhosis. Previous studies on this entity have been limited by small numbers of patients. In contrast to classical hepatocellular carcinoma, individual cases of fibrolamellar carcinoma have been reported to express cytokeratin 7. In addition, ultrastructural and serological studies have suggested that fibrolamellar carcinoma may show neuroendocrine differentiation. The cellular differentiation of fibrolamellar carcinoma has not been studied and little is reported about its immunohistochemical profile. We studied 26 cases of fibrolamellar carcinoma and 62 cases of classical hepatocellular carcinoma by immunohistochemistry for HepPar1, glypican-3, pCEA, CD10, alpha-fetoprotein, cytokeratin 20, neuroendocrine markers, and surrogate markers for biliary differentiation (cytokeratin 7, cytokeratin 19, epithelial membrane antigen, EpCAM, mCEA, B72.3, and CA19.9). In situ hybridization for albumin mRNA was also performed. Tumor cells of fibrolamellar carcinoma and hepatocellular carcinoma showed positive signals for albumin mRNA by in situ hybridization in all cases. Both tumor types stained uniformly positively with HepPar1 and most showed a canalicular staining pattern for pCEA, confirming their hepatocellular differentiation. In addition, 39% of hepatocellular carcinoma cases and 59% of fibrolamellar carcinoma cases were positive for glypican-3. All 22 fibrolamellar carcinoma cases tested showed positive staining for cytokeratin 7 and epithelial membrane antigen, whereas less than one-third of hepatocellular carcinoma cases were positive for these markers (P<0.0001). Further, 36% of fibrolamellar carcinoma cases showed staining for B72.3, cytokeratin 19, EpCAM, or mCEA. Minimal evidence of neuroendocrine differentiation in either tumor was found with any of the usual immunohistochemical markers used for this purpose. Therefore, cytokeratin 7 and epithelial membrane antigen may be useful to differentiate between fibrolamellar carcinoma and hepatocellular carcinoma. On the basis of immunohistochemistry, fibrolamellar carcinoma seems to show both hepatocellular and bile duct differentiation.

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.

Hepatic progenitor cells in liver cancers from Asian children

BACKGROUND/AIMS

Hepatoblastoma (HB) and hepatocellular carcinoma (HCC) are the two most common primary malignant liver tumours in children. Hepatic progenitor cells have been described and can be stained with K19, EpCAM and CD117. We investigated the morphology and staining patterns of primary liver tumours in Asian children.

METHODS

Four pathologists studied slides from 39 paediatric patients from Vietnam and Korea aged 8 months to 16 years. We performed immunohistochemical stains for K19, EpCAM and CD117, and polymerase chain reaction for tissue hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA.

RESULTS

There was agreement on the diagnosis of 24 cases of HCC and 10 cases of HB (one recurrent case). The diagnosis was split for six cases (HCC/HB). All 20 cases of HCC tested were HBV DNA+ and HCV RNA-. All nine cases of HB tested were HBV DNA-, while one was HCV RNA+. Of four HCC/HB cases tested, three were HBV DNA+ and all were HCV RNA-. By immunohistochemistry, 8/24 (33%) cases of HCC were K19+ and 18/24 (75%) were EpCAM+, 5/10 (50%) cases of HB were K19+ and 7/10 (70%) were EpCAM+ and 3/6 (50%) cases of HCC/HB were K19+ and 5/6 (83%) were EpCAM+. CD117 was negative in all 38 cases tested. Paediatric HCC has a morphology different from adult HCC, sometimes resembling HB, and a larger proportion of paediatric tumours have progenitor cell features.

CONCLUSIONS

HB and HCC in children may represent malignant transformation at an early stage in the cellular lineage and often arise from hepatic progenitor cells.

Predictive power of pretreatment prognostic factors in children with hepatoblastoma: a report from the Children's Oncology Group

BACKGROUND

PRETEXT is used to stratify risk in children with hepatoblastoma by the Liver Tumor Strategy Group (SIOPEL) of the International Society of Pediatric Oncology (SIOP). A recent analysis excluding patients that did not survive neoadjuvant chemotherapy, concluded that PRETEXT was superior to Children's Oncology Group (COG) stage for predicting survival. Puzzled by this result, we made a similar comparison of PRETEXT and COG stage. This time, however, we include all patients, and we compare predictive value at diagnosis, instead of after neoadjuvant chemotherapy.

METHODS

Hepatoblastoma patients in INT-0098 were retrospectively reviewed for PRETEXT and other potential prognostic factors including pathologic subtype, and alpha-fetoprotein (AFP).

RESULTS

Five-year overall survival by PRETEXT was 88.9%, 84.5%, 71.6%, and 30.9%, for PRETEXT I, II, III, and IV, respectively. The 5-year overall survival rates by COG stage were 100%, 97.5%, 100%, 70.2%, and 39.3% for Stage I pure fetal histology (PFH), Stage I unfavorable histology (UH = not PFH), Stage II, Stage III, and Stage IV, respectively. PRETEXT added significant additional prognostic information within the COG Stage III, but not COG Stage IV. Additional prognostic factors statistically significant for an increased risk of death were small-cell-undifferentiated (SCU) histologic subtype and AFP < 100 at diagnosis.

CONCLUSIONS

PRETEXT, COG stage, SCU histology, and AFP < 100, as assessed at diagnosis, are important determinants of survival that will allow us to better develop common international criteria for risk stratification. Common risk stratification is an essential prerequisite to establish effective cooperation across the ocean in this field of rare tumors.

[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.

Guidelines for surgical treatment of hepatoblastoma in the modern era--recommendations from the Childhood Liver Tumour Strategy Group of the International Society of Paediatric Oncology (SIOPEL)

Cisplatin-containing chemotherapy and complete surgical resection are both crucial in the cure of hepatoblastoma. Radical resection can be obtained either conventionally by partial hepatectomy or with orthotopic liver transplant, but the surgical approach to hepatoblastoma differs considerably across the world. Our main aim in this paper is to present the surgical recommendations of the Childhood Liver Tumour Strategy Group of the International Society of Paediatric Oncology (SIOPEL), as well as to stimulate international debate on this issue. We discuss biopsy, verification of resectability, resection principles, indications and potential contraindications for orthotopic liver transplant, as well as thoracic surgery for pulmonary metastases. We suggest that heroic liver resections with a high probability of leaving residual tumour should be avoided whenever possible. In such cases primary orthotopic liver transplant should be considered. Superior survival rates in hepatoblastoma patients who have received a primary transplant after a good response to chemotherapy support the strategy of avoiding partial hepatectomy in cases where radical resection appears difficult and doubtful. We recommend early referral to a transplant surgeon in cases of: (i) multifocal or large solitary PRETEXT IV (PRE Treatment EXTent of disease scoring system) hepatoblastoma involving all four sectors of the liver and (ii) unifocal, centrally located tumours involving main hilar structures or main hepatic veins. Because complete tumour resection is a prerequisite for cure, any strategy leading to an increased resection rate will result in improved survival. We advise the more frequent use of orthotopic liver transplant, as well as the standardisation of techniques for partial liver resection. These guidelines should not be seen as final, but rather as a starting point for further discussion between the various national and international liver tumour study groups.

Transcatheter arterial chemoembolization in treatment of hepatoblastoma in children: A report of 15 cases

AIM: To evaluate the clinical feasibility, therapeutic effect, applications and roles of transcatheter arterial chemoemb-olization (TACE) for the unresectable hepatoblastoma in children.

METHODS: Fifteen cases of unresectable hepatoblastoma were firstly treated with TACE for 18 times before secondary surgical resection. The changes of clinical symptoms, signs and AFP before and after TACE, and the conditions of operation were analyzed. The therapeutic effect in long term was followed up for all the cases.

RESULTS: Re-examinations were performed after several days to 1 month. Tumors treated with TACE shrank with 19-82% (average 58.6%)(Paired samples test, t = 3.171, P = 0.007), and the levels of AFP reduced significantly from 29% to 89%(mean 57.38%) (Paired samples test, t = 1.784,P = 0.096). No significant chemotherapeutic toxicity was observed. Twelve cases of hepatoblastoma were safely excised. Pathological examination showed massive necrosis (63.1% on average) in the resected tumor tissues. The 1-, 2-, and 3-year survival rates were 93.3% (14/15), 66.6% (10/15) and 40%(6/15) respectively by follow-up.

CONCLUSION: TACE is a safe, effective therapeutic method for unresectable hepatoblastoma in children. It is also effective in reducing hemorrhage and tumor cell pervasion during operation.

Biliary Complications After Liver Transplantation

The incidence of biliary complications after liver transplant is estimated to be 8% to 20%. Post-liver transplant biliary complications may lead to acute and chronic liver injury. The early recognition and prompt treatment of such complications improves the long-term survival of the patient and graft. An understanding of the type of biliary reconstruction, the rationale for creating a particular anastomosis, and the technical difficulties in reconstructing the biliary tract are important in assessing and managing complications after liver transplant. Because the clinical presentation of these patients may be subtle, the physician must be aggressive and thoughtful in ordering and interpreting the diagnostic tests. Important points to remember are 1) that noninvasive examinations may fail to detect small obstructions or leaks, 2) a liver biopsy often is performed prior to cholangiography to exclude rejection and ischemia, and 3) the liver biopsy can miss an extrahepatic obstruction by misinterpreting portal inflammation as rejection. Biliary leaks and strictures are the most common biliary complications following liver transplant. Less common complications include ampullary dysfunction and stone/sludge formation. The effective management of biliary complications following a liver transplant depends on understanding the natural history, the prognosis, and the available therapeutic options for each type of complication.