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

Unresectable hepatoblastoma: current perspectives

Although rare, hepatoblastoma is the most common pediatric liver tumor. Complete resection is a critical component for cure; however, most patients will have tumors that are not resected at diagnosis. For these patients, administration of neoadjuvant chemotherapy renders tumors resectable in most patients. For patients whose tumors remain unresectable after chemotherapy, liver transplantation is indicated (in the absence of active unresectable metastatic disease). In patients whose tumors remain unresectable after conventional chemotherapy, interventional techniques may serve as a promising option to reduce tumor size, decrease systemic toxicity, decrease need for liver transplantation, and increase feasibility of tumor resection.

Risk-stratified staging in paediatric hepatoblastoma: a unified analysis from the Children's Hepatic tumors International Collaboration

BACKGROUND

Comparative assessment of treatment results in paediatric hepatoblastoma trials has been hampered by small patient numbers and the use of multiple disparate staging systems by the four major trial groups. To address this challenge, we formed a global coalition, the Children's Hepatic tumors International Collaboration (CHIC), with the aim of creating a common approach to staging and risk stratification in this rare cancer.

METHODS

The CHIC steering committee-consisting of leadership from the four major cooperative trial groups (the International Childhood Liver Tumours Strategy Group, Children's Oncology Group, the German Society for Paediatric Oncology and Haematology, and the Japanese Study Group for Paediatric Liver Tumours)-created a shared international database that includes comprehensive data from 1605 children treated in eight multicentre hepatoblastoma trials over 25 years. Diagnostic factors found to be most prognostic on initial analysis were PRETreatment EXTent of disease (PRETEXT) group; age younger than 3 years, 3-7 years, and 8 years or older; α fetoprotein (AFP) concentration of 100 ng/mL or lower and 101-1000 ng/mL; and the PRETEXT annotation factors metastatic disease (M), macrovascular involvement of all hepatic veins (V) or portal bifurcation (P), contiguous extrahepatic tumour (E), multifocal tumour (F), and spontaneous rupture (R). We defined five clinically relevant backbone groups on the basis of established prognostic factors: PRETEXT I/II, PRETEXT III, PRETEXT IV, metastatic disease, and AFP concentration of 100 ng/mL or lower at diagnosis. We then carried the additional factors into a hierarchical backwards elimination multivariable analysis and used the results to create a new international staging system.

RESULTS

Within each backbone group, we identified constellations of factors that were most predictive of outcome in that group. The robustness of candidate models was then interrogated using the bootstrapping procedure. Using the clinically established PRETEXT groups I, II, III, and IV as our stems, we created risk stratification trees based on 5 year event-free survival and clinical applicability. We defined and adopted four risk groups: very low, low, intermediate, and high.

INTERPRETATION

We have created a unified global approach to risk stratification in children with hepatoblastoma on the basis of rigorous statistical interrogation of what is, to the best of our knowledge, the largest dataset ever assembled for this rare paediatric tumour. This achievement provides the structural framework for further collaboration and prospective international cooperative study, such as the Paediatric Hepatic International Tumour Trial (PHITT).

FUNDING

European Network for Cancer Research in Children and Adolescents, funded through the Framework Program 7 of the European Commission (grant number 261474); Children's Oncology Group CureSearch grant contributed by the Hepatoblastoma Foundation; Practical Research for Innovative Cancer Control and Project Promoting Clinical Trials for Development of New Drugs and Medical Devices, Japan Agency for Medical Research; and Swiss Cancer Research grant.

Resectability and tumor response after preoperative chemotherapy in hepatoblastoma treated by the Japanese Study Group for Pediatric Liver Tumor (JPLT)-2 protocol

BACKGROUND/PURPOSE

We aimed to clarify whether surgical resectability and tumor response after preoperative chemotherapy (preCTx) represented prognostic factors for patients with hepatoblastoma (HBL) in the JPLT-2 study (1999-2012).

METHODS

Patients (N=342) with HBL who underwent preCTx were eligible. PRETEXT, CHIC risk stratification (standard [SR], intermediate [IR] and high risk [HR]) at diagnosis, POST-TEXT, and tumor resectability were evaluated by imaging. Tumor response was classified into responders (CR or PR) and nonresponders (NC or PD) according to RECIST criteria.

RESULTS

There were 7 PRETEXT I, 106 II, 143 III, and 86 IV, including 71 metastatic HBLs. In POST-TEXT, 12 PRETEXT II, 42 III, and 58 IV were down-staged. The 5-year EFS/OS rates of 198 SR, 73 IR, and 71 HR-HBLs were 82/94%, 49/64%, and 28/34%, respectively. In 198 SR, 154 of 160 responders and 24 of 38 nonresponders survived event-free (P<0.01). In 73 IR, 12 of 24 whose tumors remained unresectable experienced recurrence, 9 of whom were nonresponders (P<0.01). In 71 HR, chemoresponders and tumor resectability after preCTx correlated with favorable outcomes (P<0.05).

CONCLUSIONS

Evaluation of response and tumor resectability after preCTx is useful for predicting prognosis in HBLs. To improve outcomes, we should reconsider surgical procedures according to resectability and chemoresponsiveness.

LEVEL OF EVIDENCE

Level II.

Benefit of early inflow exclusion during living donor liver transplantation for unresectable hepatoblastoma

BACKGROUND

Hepatoblastoma (HB) is a highly malignant primary liver tumor in children. Although liver transplantation (LT) is an effective treatment for unresectable HB with good long-term outcomes, post-transplant survival is mainly affected by recurrence, despite adjuvant chemotherapy. Novel strategies are needed to improve the outcomes in patients undergoing LT for unresectable HB.

PATIENTS AND METHODS

Twelve children received LT for unresectable HB. In 9 patients, we applied early exclusion of hepatic inflow (hepatic artery and portal vein) and creation of a temporary portocaval shunt during LT.

RESULT

There were differences in the duration of and the blood loss during operation as compared with previously reports. The estimated glomerular filtration rate was well preserved at 3, 6, and 12months and the latest follow-up after LT, and the recurrence-free survival was 88.9%.

CONCLUSION

Early inflow control during LT for unresectable HB may benefit recurrence-free survival by minimizing blood loss and tumor dissemination, preserving renal function and allowing early adjuvant chemotherapy.

Three-dimensional printing and pediatric liver disease

PURPOSE OF REVIEW

Enthusiastic physicians and medical researchers are investigating the role of three-dimensional printing in medicine. The purpose of the current review is to provide a concise summary of the role of three-dimensional printing technology as it relates to the field of pediatric hepatology and liver transplantation.

RECENT FINDINGS

Our group and others have recently demonstrated the feasibility of printing three-dimensional livers with identical anatomical and geometrical landmarks to the native liver to facilitate presurgical planning of complex liver surgeries. Medical educators are exploring the use of three-dimensional printed organs in anatomy classes and surgical residencies. Moreover, mini-livers are being developed by regenerative medicine scientist as a way to test new drugs and, eventually, whole livers will be grown in the laboratory to replace organs with end-stage disease solving the organ shortage problem.

SUMMARY

From presurgical planning to medical education to ultimately the bioprinting of whole organs for transplantation, three-dimensional printing will change medicine as we know in the next few years.

Malignant tumors of the liver in children

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

Pediatric liver transplantation: Personal perspectives on historical achievements and future challenges

This review presents the author's personal perspective and contributions to the first steps, the development, the current status, and the remaining issues of pediatric liver transplantation (LT). Innumerable children around the world who have undergone LT have reached adulthood. The techniques have reached maturity. As shown by my own group's experience, grafts donated by living donors might provide the best short-term and longterm results. Debate persists about the optimal immunosuppression (IS), although the place of tacrolimus remains unchallenged. Tolerance induction protocols aiming to induce microchimerism have been tried in clinical transplantation without convincing results. Withdrawal of maintenance IS is possible in some children who underwent liver transplantation who have excellent clinical status and normal liver function tests but is not without risk of rejection and subsequent worsening of histology. The current trend favored by the Brussels' group is to minimize IS as soon after transplant as possible, aiming to obtain a state of "prope" or "almost" tolerance. Liver grafts are threatened in the long term by increasing hepatitis-related fibrosis, resulting most likely from immunological assault. Nowadays, the focus is on the longterm survival, quality of life (growth, academic performance, employment, self-fulfillment, fertility, raising a family, etc.), induction of tolerance, prevention of risks bound to decades of IS (nephrotoxicity and neurotoxicity, cardiovascular risk, de novo malignancies, etc.), and prevention of graft fibrosis. All these issues are fertile fields for younger scientists. Liver Transplantation 22 1284-1294 2016 AASLD.

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

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

Pediatric liver transplantation for hepatoblastoma

Hepatoblastoma is the most common pediatric liver tumor and is usually diagnosed before five years of age. Treatment consists of a combination of chemotherapy and surgery, with the goal being attainment of complete local control by surgical resection and eradication of any extrahepatic disease. Neoadjuvant chemotherapy is utilized and is often beneficial in rendering tumors resectable; however, prolonged chemotherapy administration attempting to render tumors resectable by conventional resection should be avoided. For patients whose tumors are too extensive to be conventionally resected, liver transplantation can be curative and remains the treatment of choice for eligible patients otherwise incurable by conventional resection.

Chemotherapy-induced B-cell depletion in hepatoblastoma patients undergoing ABO-incompatible living donor liver transplantation

LT from ABO-I donors requires preconditioning regimens to prevent postoperative catastrophic AMR. NAC for HBL is known to cause myelosuppression leading to a reduction in the number and function of lymphocytes. We investigated this chemotherapy-induced myelosuppression in HBL patients listed for LT from ABO-I donors with reference to the kinetics of B, T cells, and anti-ABO blood type isoagglutinin titers. Between 2005 and 2015, of the 319 patients who underwent LDLT at our institute, 12 were indicated for unresectable HBL. Three patients with unresectable HBL who underwent LDLT from ABO-I donors are included in this study. Immunosuppression consisted of a standard regime of tacrolimus and low-dose steroids as in ABO compatible/identical LDLT. No additional preoperative therapies for B-cell depletion were used. Absolute lymphocyte counts, lymphocyte subsets (including CD20+ B cells, CD3+CD4+ T cells and CD3+CD8+ T cells), and anti-ABO blood type isoagglutinin titers were measured before LDLT and postoperatively. The median age at diagnosis was 19 months (range, 3-31 months). The median follow-up was seven months (range, 6-15 months). The median interval from the last NAC to LDLT was 33 days (range, 25-52 days). The median interval from LDLT to adjuvant chemotherapy was 28 days (range, 22-36 days). The counts of CD20+ B cells before LDLT were depleted to median 5 cells/mm(3) (range, 0-6 cells/mm(3)). There was a transient rebound in the CD20+ B cell counts on day seven (maximum of 82 cells/mm(3)) followed by a decline starting at 14 days after LDLT that was sustained for the duration of adjuvant chemotherapy. Anti-ABO blood type isoagglutinin titers were lowered to between 1:1 and 1:16 before LDLT and remained low for the duration of follow-up in this study. All of the three patients remained in good health without either acute cellular or AMR after LDLT. The B-cell depletion that occurs after cisplatin-based chemotherapy for HBL may help accomplish safe ABO-I LDLT in children without the use of additional conditioning regimens for prevention of AMR.

Multidisciplinary effort in treating children with hepatoblastoma in China

The purpose of this study is to report the first nationwide protocol (Wuhan Protocol) developed by Chinese Children's Cancer Group and the results of multidisciplinary effort in treating hepatoblastoma. In this study, we reported the final analysis, which includes 153 hepatoblastoma patients in 13 hospitals from January 2006 to December 2013. The 6-year overall survival and event-free survival rates were 83.3 ± 3.1% and 71.0 ± 3.7%, respectively, in this cohort. The univariate analysis revealed that female (P = 0.027), under 5 years of age (P = 0.039), complete surgical resection (P = 0.000), no metastases (P = 0.000), and delayed surgery following neoadjuvant chemotherapy (P = 0.000) had better prognosis. In multivariate analysis, male, 5 years of age or above, stage PRETEXT III or IV, and incomplete surgical resection were among the some adverse factors contributing to poor prognosis. The preliminary results from this study showed that patients who underwent treatment following Wuhan Protocol had similar OS and EFS rates compared to those in developed countries. However, the protocol remains to be further optimized in standardizing surgical resection (including liver transplantation), refining risk stratification and risk-based chemotherapy.

Mortality and morbidity in primarily resected hepatoblastomas in Japan: Experience of the JPLT (Japanese Study Group for Pediatric Liver Tumor) trials

BACKGROUND

In the Japanese Study Group for Pediatric Liver Tumor (JPLT) protocols (JPLT-1 and 2) for evaluating the cure rate of risk-stratified hepatoblastoma, primary resection was permitted in PRETEXT I and II cases, followed by postoperative chemotherapy.

METHODS

In approximately 500 enrolled cases, resection was performed as the initial treatment in 60 cases, including all 18 PRETEXT I, 30 PRETEXT II, and 12 ruptured cases. The clinical features, surgical procedures, complications, and survival rates were compared in these three groups.

RESULTS

All 18 PRETEXT I cases underwent complete resection by lobectomy or segmentectomy (n=14) or nonanatomical partial hepatectomy (NPH) (n=4). The 30 PRETEXT II cases underwent primary resection by right or left lobectomy (n=16), NPH (n=10), or other procedures (n=4). Of these 30 cases, operational death occurred in 1 newborn, and recurrence occurred in 7 cases (14.6%), including 6 NPH cases and 4 older cases (aged >3years). Of the 12 ruptured cases, 7 (58.3%) showed recurrence. Event-free survival rates at 5years in the 3 groups were 88%, 70%, and 32%, respectively.

CONCLUSIONS

Primary resection for PRETEXT I or II HB cases should be performed by anatomical resection according to strict surgical guidelines. More intensified chemotherapy is required for primary resected cases whose tumors have ruptured.

Detection of Serum Protein Biomarkers for the Diagnosis and Staging of Hepatoblastoma

The present study aimed to identify serum biomarkers for the detection of hepatoblastoma (HB). Serum samples were collected from 71 HB patients (stage I, n = 19; stage II, n = 19, stage III, n = 19; and stage IV, n = 14) and 23 age- and sex-matched healthy children. Differential expression of serum protein markers were screened using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS), and the target proteins were isolated and purified using HPLC and identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), SEQUEST, and bioinformatics analysis. Differential protein expression was confirmed by enzyme-linked immunosorbent analysis (ELISA). SELDI-TOF-MS screening identified a differentially expressed protein with an m/z of 9348 Da, which was subsequently identified as Apo A–I; its expression was significantly lower in the HB group as compared to the normal control group (1546.67 ± 757.81 vs. 3359.21 ± 999.36, respectively; p < 0.01). Although the expression level decreased with increasing disease stage, pair-wise comparison revealed significant differences in Apo A–I expression between the normal group and the HB subgroups (p < 0.01). ELISA verified the reduced expression of Apo A–I in the HB group. Taken together, these results suggest that Apo A–I may represent a serum protein biomarker of HB. Further studies will assess the value of using Apo A–I expression for HB diagnosis and staging.

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.

The role of BH3-mimetic drugs in the treatment of pediatric hepatoblastoma

Pediatric hepatoblastoma (HB) is commonly treated by neoadjuvant chemotherapy and surgical tumor resection according to international multicenter trial protocols. Complete tumor resection is essential and survival rates up to 95% have now been achieved in those tumors classified as standard-risk HB. Drug resistance and occurrence of metastases remain the major challenges in the treatment of HB, especially in high-risk tumors. These conditions urgently require the development of alternative therapeutic strategies. One of those alternatives is the modulation of apoptosis in HB cells. HBs regularly overexpress anti-apoptotic proteins of the Bcl-family in comparison to healthy liver tissue. This fact may contribute to the development of chemoresistance of HB cells. Synthetic small inhibitory molecules with BH3-mimetic effects, such as ABT-737 and obatoclax, enhance the susceptibility of tumor cells to different cytotoxic drugs and thereby affect initiator proteins of the apoptosis cascade via the intrinsic pathway. Besides additive effects on HB cell viability when used in combination with cytotoxic drugs, BH3-mimetics also play a role in preventing metastasation by reducing adhesion and inhibiting cell migration abilities. Presumably, including additive BH3-mimetic drugs into existing therapeutic regimens in HB patients might allow dose reduction of established cytotoxic drugs and thereby associated immanent side effects, while maintaining the antitumor activity. Furthermore, reduction of tumor growth and inhibition of tumor cell dissemination may facilitate complete surgical tumor resection, which is mandatory in this tumor type resulting in improved survival rates in high-risk HB. Currently, there are phase I and phase II clinical trials in several cancer entities using this potential target. This paper reviews the available literature regarding the use of BH3-mimetic drugs as single agents or in combination with chemotherapy in various malignancies and focuses on results in HB cells.

The treatment of hepatoblastoma: Its evolution and the current status as per the SIOPEL trials

Aim of the Review:

To describe the significant improvement in the diagnosis, treatment and outcome of children diagnosed with hepatoblastoma (HB) that has occurred in the past four decades. Recent findings are mainly focused on lessons learned from the experiences of the Childhood Liver Tumors Strategy Group (SIOPEL). Important milestones were the risk stratification of HB that allowed to tailor down therapy for standard-risk HB and intensify treatment for high-risk HB. The multi-institutional international cooperative SIOPEL trials are reviewed and current treatment guidelines are given. Intensified cooperation between the SIOPEL and the Children's Oncology Group (COG) and the national study groups from Germany (GPOH) and Japan (JPLT) led to the acceptance and use of one staging system (PRETEXT) and the formation of a single robust database containing data of 1605 HB patients. This will allow analysis with enough statistical power of treatment directing factors that will form one of the bases of the next-generation clinical trial that is currently designed by all four collaborating study groups.

Summary:

Successive SIOPEL trials and increasing international collaboration have improved survival rates of patients with HB through risk stratification, advances in chemotherapy and increased complete resection rates including liver transplantation as a surgical option.

Pediatric hepatoblastoma: diagnosis and treatment

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

A child with unresectable biliary rhabdomyosarcoma: 48-month disease-free survival after liver transplantation

We describe here a two-yr-old boy with biliary RMS successfully treated by chemotherapy and LT. The child presented with obstructive jaundice at 20 months of age. A mildly vascularized, non-calcified, partially cystic lesion was visualized in the left hepatic lobe. Solid infiltration of the common bile duct and of both left and right hepatic ducts was suspected. Liver biopsy suggested a botryoid-type embryonal RMS originating from the biliary tract. After extrahepatic spread of the tumor was excluded, a biliary drain was applied and neoadjuvant chemotherapy was started. After the treatment, although reduced in volume, the mass was still unresectable without aggressive surgery and gross residual disease. LT with a reduced segment II/III graft was performed four months after diagnosis. The patient received six cycles of adjuvant chemotherapy, and he is alive and recurrence-free 48 months post-transplantation. A posteriori, the transplant might have possibly been avoided with an aggressive resection with biliary reconstruction. Nevertheless, although the risk of the transplant has to be balanced against the chemoresponsiveness of the tumor, the four-yr disease-free survival of this patient suggests that, when coupled with effective chemotherapy, transplantation might be considered a potential treatment for unresectable biliary RMS.