Search

Hepatoblastomas (HB) display heterogeneous cellular phenotypes that influence the clinical outcome, but the underlying mechanisms are poorly understood. Here, we use a single-cell multiomic strategy to unravel the molecular determinants of this plasticity. We identify a continuum of HB cell states between hepatocytic (scH), liver progenitor (scLP) and mesenchymal (scM) differentiation poles, with an intermediate scH/LP population bordering scLP and scH areas in spatial transcriptomics. Chromatin accessibility landscapes reveal the gene regulatory networks of each differentiation pole, and the sequence of transcription factor activations underlying cell state transitions. Single-cell mapping of somatic alterations reveals the clonal architecture of each tumor, showing that each genetic subclone displays its own range of cellular plasticity across differentiation states. The most scLP subclones, overexpressing stem cell and DNA repair genes, proliferate faster after neo-adjuvant chemotherapy. These results highlight how the interplay of clonal evolution and epigenetic plasticity shapes the potential of HB subclones to respond to chemotherapy., (© 2024. The Author(s).)

Background: Hepatoblastoma is the most frequent pediatric liver cancer. The current treatments lead to 80% of survival rate at 5 years. In this study, we evaluated the clinical relevance of molecular features to identify patients at risk of chemoresistance, relapse and death of disease., Methods: All the clinical data of 86 children with hepatoblastoma were retrospectively collected. Pathological slides were reviewed, tumor DNA sequencing (by whole exome, whole genome or target) and transcriptomic profiling with RNAseq or 300-genes panel were performed. Associations between the clinical, pathological, mutational and transcriptomic data were investigated., Results: High-risk patients represented 44% of our series and the median age at diagnosis was 21.9 months (range: 0-208). Alterations of the WNT/ß-catenin pathway and of the 11p15.5 imprinted locus were identified in 98% and 74% of the tumors, respectively. Other cancer driver genes mutations were only found in less than 11% of tumors. After neoadjuvant chemotherapy, disease-specific survival and poor response to neoadjuvant chemotherapy were associated with 'Liver Progenitor' (p = 0.00049, p < 0.0001) and 'Immune Cold' (p = 0.0011, p < 0.0001) transcriptomic tumor subtypes, SBS35 cisplatin mutational signature (p = 0.018, p = 0.001), mutations in rare cancer driver genes (p = 0.0039, p = 0.0017) and embryonal predominant histological type (p = 0.0013, p = 0.0077), respectively. Integration of the clinical and molecular features revealed a cluster of molecular markers associated with resistance to chemotherapy and survival, enlightening transcriptomic 'Immune Cold' and Liver Progenitor' as a predictor of survival independent of the clinical features., Conclusions: Response to neoadjuvant chemotherapy and survival in children treated for hepatoblastoma are associated with genomic and pathological features independently of the clinical features., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Pediatric liver tumors are very rare tumors with the most common diagnosis being hepatoblastoma. While hepatoblastomas are predominantly sporadic, around 15% of cases develop as part of predisposition syndromes such as Beckwith-Wiedemann (11p15.5 locus altered). Here, we identify mosaic genetic alterations of 11p15.5 locus in the liver of hepatoblastoma patients without a clinical diagnosis of Beckwith-Wiedemann syndrome. We do not retrieve these alterations in children with other types of pediatric liver tumors. We show that mosaic 11p15.5 alterations in liver FFPE sections of hepatoblastoma patients display IGF2 overexpression and H19 downregulation together with an alteration of the liver zonation. Moreover, mosaic livers' microenvironment is enriched in extracellular matrix and angiogenesis. Spatial transcriptomics and single-nucleus RNAseq analyses identify a 60-gene signature in 11p15.5 altered hepatocytes. These data provide insights for 11p15.5 mosaicism detection and its functional consequences during the early steps of carcinogenesis., (© 2023. The Author(s).)

Background and Aims: Prognosis of hepatoblastoma patients has increased with cisplatin-based chemotherapy and high-quality resection including liver transplant. Consequently current risk-adapted therapeutic strategy aims to reduce long-term side effects in patients with standard risk disease., Methods: We report long-term mortality and morbidity data concerning 151 2-year hepatoblastoma survivors treated with SIOPEL risk-adapted strategies (sex-ratio M/F = 1.6, median age at diagnosis = 2.6 years [range 0-17.7], median year at diagnosis = 2008 [1994-2017]). Fifty-three patients had loco-regional risk factors VPEFR, 12 were PRETEXT-IV and 30 were metastatic. All received cisplatin and 84 anthracyclines. Twelve had liver transplant. To assess hearing, renal and cardiac functions, audiograms were performed in 116/151 patients (76.8%), glomerular filtration rate in 113/151 (74.8%) and cardiac ultrasound in 65/84 (77.4%) anthracycline-exposed patients., Results: With a median follow-up of 9.4 years (range 2.1-25.8), four late relapses, one second malignancy (Acute Myeloid Leukemia AML-M5) and two deaths (one from hepatoblastoma, one from AML) occurred. The 10-years event free survival and overall survival probabilities were 95.5% (95% CI 91.9-99.1) and 98.7% (95% CI 96.8-100), respectively. Sixty-eight non-oncologic health-events included 57 cases of hearing loss (including 25 Brock 3-4), three liver cirrhosis, three pre-operative portal cavernoma, two focal nodular hyperplasia, two grade-1 chronic kidney diseases and one asymptomatic cardiac dysfunction were reported. Ototoxicity was significantly associated with cisplatin cumulative dose (OR = 2.07, 95% CI 1.32-3.24, p = 0.001) and carboplatin exposure (OR = 3.14, 95% CI 1.30-7.58, p = 0.01) in multivariable analysis adjusted for sex and age at diagnosis., Conclusions: With current risk-adapted strategies, hepatoblastoma is a highly curable disease, with very rare relapses, and few late effects except hearing loss which remains a serious condition in these very young patients., (© 2021. Asian Pacific Association for the Study of the Liver.)

Pediatric liver cancers (PLC) comprise diverse diseases affecting infants, children, and adolescents. Despite overall good prognosis, PLCs display heterogeneous response to chemotherapy. Integrated genomic analysis of 126 pediatric liver tumors showed a continuum of driver mechanisms associated with patient age, including new targetable oncogenes. In 10% of patients with hepatoblastoma, all before three years old, we identified a mosaic premalignant clonal expansion of cells altered at the 11p15.5 locus. Analysis of spatial and longitudinal heterogeneity revealed an important plasticity between "hepatocytic," "liver progenitor," and "mesenchymal" molecular subgroups of hepatoblastoma. We showed that during chemotherapy, "liver progenitor" cells accumulated massive loads of cisplatin-induced mutations with a specific mutational signature, leading to the development of heavily mutated relapses and metastases. Drug screening in PLC cell lines identified promising targets for cisplatin-resistant progenitor cells, validated in mouse xenograft experiments. These data provide new insights into cisplatin resistance mechanisms in PLC and suggest alternative therapies. SIGNIFICANCE: PLCs are deadly when they resist chemotherapy, with limited alternative treatment options. Using a multiomics approach, we identified PLC driver genes and the cellular phenotype at the origin of cisplatin resistance. We validated new treatments targeting these molecular features in cell lines and xenografts. This article is highlighted in the In This Issue feature, p. 2355 ., (©2021 American Association for Cancer Research.)

Background: Hepatoblastoma tumor rupture is a high-risk criterion in the SIOPEL 3/4 protocol. Little is known about the outcome of these children., Methods: Radiological signs of possible tumor rupture, defined as peritoneal effusion, peritoneal nodules, or hepatic subcapsular hematoma, were reported in 24 of 150 patients treated for hepatoblastoma in France from January 2000 to December 2014 after central radiological expert review., Results: Twenty-two patients with available clinical data were included (nine PRETEXT-I/II, six PRETEXT-III, seven PRETEXT-IV, and five had lung metastases). Five patients had a subcapsular hematoma only, and 17 patients had intraperitoneal rupture (subcapsular hematoma and peritoneal effusion). A hepatic biopsy was performed in 19 patients. Intraperitoneal rupture occurred before biopsy in 12 and after biopsy in three (including one with prebiopsy subcapsular hematoma) (missing data: two). All patients were treated with chemotherapy, with high-risk regimens including cisplatin or carboplatin and doxorubicin in 19 and cisplatin or carboplatin alone in three. Liver surgery was performed in 20 patients (including three liver transplants). Fifteen patients (68%) achieved complete remission. With a median follow-up of 5.5 years, 11 events occurred (six progressions and three relapses, including three peritoneal progressions/relapses, one surgical complication, and one second cancer) and eight patients died. One of eight patients with no other high-risk criterion had a relapse. The three-year event-free survival and overall survival rates were 49.6% (95% CI = 30-69) and 68.2% (40-84), respectively., Conclusions: Tumor rupture is predictive of poor prognosis with risk of peritoneal progression/relapse. However, it should not be a contraindication for liver transplantation., (© 2020 Wiley Periodicals LLC.)

Background and Purpose: Conventional treatments of systemic chemotherapy and surgical resection for recurrent or metastatic hepatoblastoma (HB) may be inhibitive for the pediatric patient and family who have already been through extensive therapies. This single-institution case series evaluates the safety and efficacy of percutaneous radiofrequency ablation (RFA) in the management of metastatic HB., Materials and Methods: Between March 2008 and February 2015, RFA was used as part of multidisciplinary management for HB recurrence or metastasis in 5 children (median 5.0 years old) in an attempt to provide locoregional control and preclude additional surgery. Combined local treatments of 38 metachronous metastases included surgical metastasectomy (14 lesions: 7 lung, 7 liver), percutaneous RFA (23 lesions: 21 lung, 1 liver, 1 bone), and stereotactic radiotherapy (1 liver lesion)., Results: For lesions treated with RFA (median diameter 6 mm, range 3-15 mm), local control was achieved in 22/23 metastases (95.6%) with median follow-up of 30.1 months after RFA (range 18.9-65.7). Median hospitalization was 3 days (2-7), with major complications limited to 1 pneumothorax requiring temporary small-caliber chest tube. Four children remain in complete remission with median follow-up of 67 months (range 41.2-88.8) after primary tumor resection, with mean disease-free survival of 31.7 months after last local treatment. One child succumbed to rapidly progressive disease 12 months after RFA (23.9 months after primary tumor resection)., Conclusion: RFA provides a safe and effective reiterative treatment option in the multidisciplinary management of children with metastatic HB.

Background: Diagnosis of hepatoblastoma (HBL) is based on characteristic clinical and radiological presentation, young age and marked elevation of serum α-fetoprotein (aFP). Fine needle aspiration (FNA) technique is successfully used in the diagnosis of hepatoblastoma. To evaluate the value of FNA in the diagnosis and subtyping of HBL, we report our experience correlated to histological sections (core needle biopsy, CNB)., Methods: From 1991 to 2015, 21 cases from 20 patients were cytologically diagnosed as HBL. The patients were 15 males and 5 females, mean age being 3 years, and median age being 2 years and 4 months. Serum aFP levels ranged from negative to 1,285,000 ng/ml. We defined cytological criteria to diagnose fetal, embryonal, mesenchymal, and small cell undifferentiated components., Results: The accurate cytological diagnosis of HBL was made in all cases; 8 cases exhibited a single component and 13 cases exhibited two or more components. Fetal and embryonal components were seen in 18 and 13 cases, respectively, and small cell undifferentiated component was seen in one case. Mesenchymal component was seen in 12 cases. Comparing cytology and histology, identical components were identified on both, FNA and CNB in 14 cases. When analyzing only the presence of epithelial components, 17 cases were concordant in both techniques., Conclusion: FNA allows to accurately diagnose HBL and recognize its histological subtypes. On the basis of high concordance between cytological and histological diagnosis, FNA is validated as an alternative diagnostic method to CNB. Diagn. Cytopathol. 2017;45:91-100. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Background: The purpose of the current study was to describe pure and mixed fibrolamellar hepatocellular carcinoma (FL-HCC)., Methods: Consecutive patients with pure and mixed FL-HCC were identified from a central pathological review using Edmondson's criteria. Clinical, pathological, and epigenetic characteristics of patients who underwent curative surgery were evaluated. Overall and disease-free survival as well as patterns of disease recurrence were examined. Methylation levels of L1 retrotransposon (LINE-1) repetitive elements and Ras association domain family 1A gene (RASSF1) promoter were also assessed using pyrosequencing., Results: Forty of 53 patients with a median age of 22 years (range, 9 years-;65 years) met the criteria for analysis. Central pathological review found that 30 patients (75%) had pure and 10 patients (25%) had mixed FL-HCC. Pure FL-HCC typically occurred in patients aged < 30 years. These patients often presented with lymph node metastasis at the time of diagnosis and frequently experienced extrahepatic recurrences (n = 16). Conversely, mixed FL-HCC appeared to resemble to classic HCC, occurring in patients aged > 40 years and frequently involving the liver as the primary site of disease recurrence. With a median follow-up of 7.8 years, the median overall survival from the time of diagnosis in all patients was 6.4 years (range, 3.2 years-12 years). Multivariate analysis found that the risk of death was increased in patients with higher American Joint Committee on Cancer disease stages (P = .003) and those with mixed FL-HCC (P = .03). Methylation analysis of LINE-1 repetitive elements and RASSF1 promoter revealed different methylation levels between pure and mixed FL-HCC, suggesting a different epigenetic background., Conclusions: Pure and mixed FL-HCC display distinct clinical presentations and epigenetic backgrounds leading to different prognoses and as such may be regarded as separate clinical entities., (Copyright © 2012 American Cancer Society.)