Summary 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. Findings 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 Cli...

Tumor-specific LOH for both chromosomes 1p and 16q identifies a subset of FH Wilms tumor patients who have a significantly increased risk of relapse and death. LOH for these chromosomal regions can now be used as an independent prognostic factor together with disease stage to target intensity of treatment to risk of treatment failure.

Liver tumors are rare in children, and their diagnoses may be challenging particularly because of the lack of a current consensus classification system. Systematic central histopathological review of these tumors performed as part of the pediatric collaborative therapeutic protocols has allowed the identification of histologic subtypes with distinct clinical associations. As a result, histopathology has been incorporated within the Children's Oncology Group (COG) protocols, and only in the United States, as a risk-stratification parameter and for patient management. Therefore, the COG Liver Tumor Committee sponsored an International Pathology Symposium in March 2011 to discuss the histopathology and classification of pediatric liver tumors, and hepatoblastoma in particular, and work towards an International Pediatric Liver Tumors Consensus Classification that would be required for international collaborative projects. Twenty-two pathologists and experts in pediatric liver tumors, including those serving as central reviewers for the COG, European Socié té Internationale d'Oncologie Pé diatrique, Gesellschaft fü r Pä diatrische Onkologie und Hä matologie, and Japanese Study Group for Pediatric Liver Tumors protocols, as well as pediatric oncologists and surgeons specialized in this field, reviewed more than 50 pediatric liver tumor cases and discussed classic and newly reported entities, as well as criteria for their classification. This symposium represented the first collaborative step to develop a classification that may lead to a common treatment-stratification system incorporating tumor histopathology. A standardized, clinically meaningful classification will also be necessary to allow the integration of new biological parameters and to move towards clinical algorithms based on patient characteristics and tumor genetics, which should improve future patient management and outcome.

The prognosis for patients with stage I AH is worse than that for patients with stage I FH. Novel treatment strategies are needed to improve outcomes for patients with AH, especially those with stage III to V disease.

Introduction Contemporary state-of-the-art management of cancer is increasingly defined by individualized treatment strategies. For very rare tumors, like hepatoblastoma, the development of biologic markers, and the identification of reliable prognostic risk factors for tailoring treatment, remains very challenging. The Children's Hepatic tumors International Collaboration (CHIC) is a novel international response to this challenge. Methods Four multicenter trial groups in the world, who have performed prospective controlled studies of hepatoblastoma over the past two decades (COG; SIOPEL; GPOH; and JPLT), joined forces to form the CHIC consortium. With the support of the data management group CINECA, CHIC developed a centralized online platform where data from eight completed hepatoblastoma trials were merged to form a database of 1605 hepatoblastoma cases treated between 1988 and 2008. The resulting dataset is described and the relationships between selected patient and tumor characteristics, and risk for adverse disease outcome (event-free survival; EFS) are examined. Results Significantly increased risk for EFS-event was noted for advanced PRETEXT group, macrovascular venous or portal involvement, contiguous extrahepatic disease, primary tumor multifocality and tumor rupture at enrollment. Higher age (≥8 years), low AFP (<100 ng/ml) and metastatic disease were associated with the worst outcome. Conclusion We have identified novel prognostic factors for hepatoblastoma, as well as confirmed established factors, that will be used to develop a future common global risk stratification system. The mechanics of developing the globally accessible web-based portal, building and refining the database, and performing this first statistical analysis has laid the foundation for future collaborative efforts. This is an important step for refining of the risk based grouping and approach to future treatment stratification, thus we think our collaboration offers a template for others to follow in the study of rare tumors and diseases.

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 5-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.

Children with initially resectable HCC have a good prognosis and may benefit from the use of adjuvant chemotherapy. Outcome was uniformly poor for children with advanced-stage disease treated with either regimen. New therapeutic strategies are needed for the treatment of advanced-stage pediatric HCC.

These results demonstrate that approximately one-half of children with unilateral WT who relapse after initial treatment with VAD and radiation therapy can be successfully retreated.