Histological and immunohistochemical study of hepatoblastoma: correlation with tumour behaviour and survival

FOXM1 and CHD4 expression is associated with chemoresistance in hepatoblastoma

Hepatoblastoma (HB) is the most common malignant liver tumor in childhood. Although pre-operative cisplatin (CDDP)-based chemotherapy is often used in cases of HB, about 20％ of HB patients exhibit resistance to CDDP. Forkhead box protein M1 (FOXM1) and chromo-domain-helicase-DNA-binding protein 4 (CHD4) have been associated with CDDP resistance in various tumors. We here analyzed the immunohistochemical expression of FOXM1 and CHD4 in HB specimens of 33 patients (mean age: 20 months) post-chemotherapy. The differentiation of specimens was assessed using the digital pathology software QuPath®, and then the relation between the FOXM1 or CHD4 expression and the differentiation and various other clinicopathological parameters was investigated. The histological type was epithelial in 19 cases (57.6%) and mixed epithelial and mesenchymal in 14 cases (42.4%). Nine cases had only a fetal component, 1 case had only an embryonal component, 22 cases had both fetal and embryonal components, and 1 case had no viable tumor. Both the FOXM1 and CHD4 immunoexpressions were found significantly more frequently in the embryonal than fetal components (p<0.0001 and p<0.0001, respectively). Regarding chemotherapy efficacy, the alpha-fetoprotein (AFP) level after chemotherapy was correlated with both the imaging shrinkage rate (R=-0.52) and histological residual rate (the percentage of the viable tumors of HB after chemotherapy)(R=0.62). High FOXM1 score was correlated with a high-postoperative AFP value (p<0.01) and a low AFP attenuation rate (p<0.05), but the FOXM1 score was not correlated with the imaging shrinkage rate (p=0.4418) or histological residual rate (p=0.4418). High CHD4 score showed a nonsignificant trend toward correlation with high postoperative AFP value (p=0.0849) and was not significantly correlated with the other parameters. Collectively, our results showed that FOXM1 expression may be useful in evaluating the response to CDDP-based chemotherapeutic regimens. Accurate measurement of FOXM1 expression by our scoring system using QuPath® is important in cases with mixed HB components of various differentiation levels.

Prognostic and predictive biomarkers in paediatric solid tumours

Characterisation of histological, immunohistochemical and molecular prognostic and predictive biomarkers has contributed significantly to precision medicine and better outcomes in the management of paediatric solid tumours. Prognostic biomarkers allow predictions to be made regarding a tumour's aggressiveness and clinical course, whereas predictive biomarkers help determine responses to a specific treatment. This review summarises prognostic biomarkers currently used in the more common paediatric solid tumours, with a brief commentary on the most relevant less common predictive biomarkers. MYCN amplification is the most important genetic alteration in neuroblastoma prognosis, and the histological classification devised by Shimada in 1999 is still used in routine diagnosis. Moreover, a new subgrouping of unfavourable histology neuroblastoma enables immunohistochemical characterisation of tumours with markedly different genetic features and prognosis. The predominant histology and commonly observed cytogenetic abnormalities are recognised outcome predictors in Wilms tumour. Evaluation for anaplasia, which is tightly associated with TP53 gene mutations and poor outcomes, is central in both the International Society of Paediatric Oncology and the Children's Oncology Group approaches to disease classification. Characterisation of distinct genotype-phenotype subclasses and critical mutations has expanded overall understanding of hepatoblastoma outcomes. The C1 subclass hepatoblastoma and CTNNB1 mutations are associated with good prognosis. In contrast, the C2 subclass, NFE2L2 mutations, TERT promoter mutations and high expression of oncofetal proteins and stem cell markers are associated with poor outcomes. Risk stratification in sarcomas is highly variable depending on the entity. The prognosis of rhabdomyosarcoma, for example, primarily depends on histological and molecular characteristics. Advances in our understanding of clinically significant biomarkers will translate into more precise diagnoses, improved risk stratification and more effective and less toxic treatment in this challenging group of patients.

AFP deletion leads to anti-tumorigenic but pro-metastatic roles in liver cancers with concomitant CTNNB1 mutations

HCC remains one of the most prevalent and deadliest cancers. Serum AFP level is a biomarker for clinical diagnosis of HCC, instead the contribution of AFP to HCC development is clearly highly complex. Here, we discussed the effect of AFP deletion in the tumorigenesis and progression of HCC. AFP deletion in HepG2 cells inhibited the cell proliferation by inactivating PI3K/AKT signaling. Surprisingly, AFP KO HepG2 cells appeared the increasing metastatic capacity and EMT phenotype, which was attributed to the activation of WNT5A/β-catenin signal. Further studies revealed that the activating mutations of CTNNB1 was closely related with the unconventional pro-metastatic roles of AFP deletion. Consistently, the results of DEN/CCl4-induced HCC mouse model also suggested that AFP knockout suppressed the growth of HCC primary tumors, but promoted lung metastasis. Despite the discordant effect of AFP deletion in HCC progression, a drug candidate named OA showed the potent suppression of HCC tumor growth by interrupting AFP-PTEN interaction and, importantly, reduced the lung metastasis of HCC via angiogenesis suppression. Thus, this study demonstrates an unconventional effect of AFP in HCC progression, and suggests a potent candidate strategy for HCC therapy.

Occurrence of Hepatoblastomas in Patients with Beckwith-Wiedemann Spectrum (BWSp)

Patients with Beckwith-Wiedemann syndrome (BWS), an epigenetic imprinting disorder involving alterations in genes at the 11p15 chromosomal location, are predisposed to develop hepatoblastomas (HBs), which are rare embryonal liver tumors. Tumors can develop after a BWS diagnosis or, conversely, can be the presenting feature leading to a subsequent diagnosis. While HBs are the cardinal tumors of BWS, not all patients with the BWS spectrum will develop HBs. This observation has led to many hypotheses, including genotype-associated risk, tissue mosaicism, and tumor-specific second hits. To explore these hypotheses, we present the largest cohort of patients with BWS and HBs to date. Our cohort comprised 16 cases, and we broadened our sample size by searching the literature for all cases of BWS with HBs. From these isolated case studies, we amassed another 34 cases, bringing the total number to 50 cases of BWS-HB. We observed that paternal uniparental isodisomy (upd(11)pat) was the most common genotype, representing 38% of cases. The next most common genotype was IC2 LOM, representing 14% of cases. Five patients had clinical BWS without a molecular diagnosis. To investigate the potential mechanism of HBs in BWS, we analyzed normal liver and HB samples from eight cases and isolated tumor samples from another two cases. These samples underwent methylation testing, and 90% of our tumor samples underwent targeted cancer next-generation sequencing (NGS) panels. These matched samples provided novel insights into the oncogenesis of HBs in BWS. We found that 100% of the HBs that underwent NGS panel testing had variants in the CTNNB1 gene. We further identified three distinct groups of BWS-HB patients based on epigenotype. We also demonstrated epigenotype mosaicism, where 11p15 alterations can differ between the blood, HB, and normal liver. In light of this epigenotype mosaicism, tumor risk assessment based on blood profiling may not be accurate. Therefore, universal screening is recommended for all patients with BWS.

CD203c is expressed by human fetal hepatoblasts and distinguishes subsets of hepatoblastoma

Background & Aims

Hepatocytic cells found during prenatal development have unique features compared to their adult counterparts, and are believed to be the precursors of pediatric hepatoblastoma. The cell-surface phenotype of hepatoblasts and hepatoblastoma cell lines was evaluated to discover new markers of these cells and gain insight into the development of hepatocytic cells and the phenotypes and origins of hepatoblastoma.

Methods

Human midgestation livers and four pediatric hepatoblastoma cell lines were screened using flow cytometry. Expression of over 300 antigens was evaluated on hepatoblasts defined by their expression of CD326 (EpCAM) and CD14. Also analyzed were hematopoietic cells, expressing CD45, and liver sinusoidal-endothelial cells (LSECs), expressing CD14 but lacking CD45 expression. Select antigens were further examined by fluorescence immunomicroscopy of fetal liver sections. Antigen expression was also confirmed on cultured cells by both methods. Gene expression analysis by liver cells, 6 hepatoblastoma cell lines, and hepatoblastoma cells was performed. Immunohistochemistry was used to evaluate CD203c, CD326, and cytokeratin-19 expression on three hepatoblastoma tumors.

Results

Antibody screening identified many cell surface markers commonly or divergently expressed by hematopoietic cells, LSECs, and hepatoblasts. Thirteen novel markers expressed on fetal hepatoblasts were identified including ectonucleotide pyrophosphatase/phosphodiesterase family member 3 (ENPP-3/CD203c), which was found to be expressed by hepatoblasts with widespread expression in the parenchyma of the fetal liver. In culture CD203c⁺CD326⁺⁺ cells resembled hepatocytic cells with coexpression of albumin and cytokeratin-19 confirming a hepatoblast phenotype. CD203c expression declined rapidly in culture whereas the loss of CD326 was not as pronounced. CD203c and CD326 were co-expressed on a subset of hepatoblastoma cell lines and hepatoblastomas with an embryonal pattern.

Conclusions

CD203c is expressed on hepatoblasts and may play a role in purinergic signaling in the developing liver. Hepatoblastoma cell lines were found to consist of two broad phenotypes consisting of a cholangiocyte-like phenotype that expressed CD203c and CD326 and a hepatocyte-like phenotype with diminished expression of these markers. CD203c was expressed by some hepatoblastoma tumors and may represent a marker of a less differentiated embryonal component.

Inhibition of Heat Shock Factor 1 Signaling Decreases Hepatoblastoma Growth via Induction of Apoptosis

Although rare compared with adult liver cancers, hepatoblastoma (HB) is the most common pediatric liver malignancy, and its incidence is increasing. Currently, the treatment includes surgical resection with or without chemotherapy, and in severe cases, liver transplantation in children. The effort to develop more targeted, HB-specific therapies has been stymied by the lack of fundamental knowledge about HB biology. Heat shock factor 1 (HSF1), a transcription factor, is a canonical inducer of heat shock proteins, which act as chaperone proteins to prevent or undo protein misfolding. Recent work has shown a role for HSF1 in cancer beyond the canonical heat shock response. The current study found increased HSF1 signaling in HB versus normal liver. It showed that less differentiated, more embryonic tumors had higher levels of HSF1 than more differentiated, more fetal-appearing tumors. Most strikingly, HSF1 expression levels correlated with mortality. This study used a mouse model of HB to test the effect of inhibiting HSF1 early in tumor development on cancer growth. HSF1 inhibition resulted in fewer and smaller tumors, suggesting HSF1 is needed for aggressive tumor growth. Moreover, HSF1 inhibition also increased apoptosis in tumor foci. These data suggest that HSF1 may be a viable pharmacologic target for HB treatment.

A nomogram model to predict prognosis of patients with hepatoblastoma

BACKGROUND

Hepatoblastomas (HBs) are malignant liver tumors that most commonly develop in pediatric patients. Microvascular invasion may be a prognosis factor for patients with HBs. This study aimed to construct a model to predict the survival outcome in HBs.

METHODS

We retrospectively analyzed the clinical data of 311 patients with HBs who underwent surgical resection at our institution between June 2014 and August 2021. First, patients were divided into two groups: those who had pathologic microvascular invasion (n = 146) and those who did not (n = 165). Propensity score-matched (PSM) analysis was carried out between the two groups. The preoperative parameters and overall survival (OS) rate were compared between the two groups. Second, all 311 patients were randomly divided into the training and validation cohort in a ratio of 4:1. A nomogram was created in the training cohort to visualize the prediction of OS. Moreover, the validation cohort was used for validation.

RESULTS

Multivariate analysis suggested that age, histology type, microvascular invasion, multifocality, distant metastasis, and macrovascular involvement are independent prognostic factors for HBs. The nomogram showed good predictive ability in the training and validation cohorts with a C-index of 0.878 (95% CI, 0.831-0.925) and 0.847 (95% CI, 0.757-0.937), respectively. The calibration curve indicated good agreement between the prediction and observation for one-, two-, and three-year OS probabilities.

CONCLUSION

By combining preoperative imaging results and other clinical data, we established a nomogram to predict OS probability for patients with HB, which could be a potential tool to guide personalized treatment.

A Case of Infantile Hepatic Hemangioendothelioma/Hemangioma at Maharaj Nakorn Chiang Mai Hospital

Infantile hepatic hemangioendothelioma/hemangioma is the most common benign hepatic vascular tumor of infancy, comprising approximately 1% of all childhood tumors. The tumor can present during the fetal or neonatal period as a hepatic mass. Common presentations include abdominal distension and a palpable hepatic mass. Clinico-radio-pathological correlation is essential for a definite diagnosis. Frequent complications such as congestive heart failure, thrombocytopenia, anemia, and Kasabach-Merritt syndrome should be investigated. Chemotherapy has been reported as an effective treatment option. Surgical resection has an essential role for symptomatic patients with medical treatment failure or other certain conditions such as refusal to take medication. Furthermore, prenatal diagnosis is essential for better patient outcomes due to prompt treatment in the neonatal period. We report a case of a female infant at 39 weeks of gestation who was delivered from a 32-year-old mother. The infant was in utero diagnosed by ultrasonography with a hepatic mass, most likely hemangioma. The mass was resected after birth and it was diagnosed as infantile hepatic hemangioendothelioma type II. The course of the disease was excellent and the patient was cured after treatment.

Surgical Pathology Diagnostic Pitfalls of Hepatoblastoma

Hepatoblastoma (HB) is the most common malignancy within the rare cohort of pediatric primary liver tumors. It may arise sporadically or in association with germline mutations in specific genetic syndromes. Histogenesis recapitulates fetal hepatic development, however, this tumor can exhibit a markedly heterogeneous appearance both macroscopically and under the microscope. Histologic subtypes are classified based on morphologic appearance, with additional discrimination based on emerging molecular and immunohistochemical features. Numerous diagnostic pitfalls exist from clinical presentation through to ancillary testing; at all stages, the surgical pathologist must be discerning and open to collaboration with colleagues of different specialties. Problematic areas include the adequacy of tissue sampling, correlation of histology with radiologic appearance and alpha feto-protein (AFP) serology, forming a diagnostic consensus within the pediatric pathology community and choosing a shrewd immunohistochemical panel. This review discusses the sequence of events leading up to histologic assessment, and the nuances of microscopic evaluation. Along the way, pitfalls are highlighted, providing a tool for the surgical pathologists to support their individual approach.

A large undifferentiated sarcoma of the liver in a 13-year-old girl treated with anatomical resection: a case report and review of the literature

Background

Undifferentiated embryonal sarcoma of the liver (UESL) is a rare liver tumor accounting for 6–13% of primary liver tumors. Accurate preoperative diagnosis is difficult, with a rather high misdiagnosis rate. Herein, we reported a very large UESL treated with anatomical resection. Our case is amongst the largest pediatric UESLs in the literature.

Case presentation

Herein, we report a 13-year-old girl presenting with right upper quadrant abdominal pain, postprandial vomiting, and abdominal distention, in which radiographic imaging demonstrated a huge UESL (28 × 20 × 12 cm). The patient was treated with partial hepatectomy and the 5 kg tumor was removed. The patient was discharged in good condition, with no significant complaints in her follow-up.

Conclusions

Although different treatment strategies have been reported for UESL cases, anatomical resection is still the main treatment approach, especially for large tumors.

Immunohistochemical Expression Analysis of EpCAM in Hepatoblastomas

The epithelial cell adhesion molecule (EpCAM) is involved in oncogenesis of hepatoblastomas (HBs). Prior genomic profiling studies showed higher EpCAM expression and worse prognosis in HBs containing primitive histotypes, however, this has not been fully addressed from an immunohistochemical perspective. Our goal is to characterize differential EpCAM immunohistochemistry (EpCAM-IHC) among HBs histotypes. We retrieved 62 HBs from 52 patients. EpCAM-IHC was performed (anti-MOC-31, 1:50 dilution; Cell Marque Corporation, Rocklin, CA) and graded in histotypes using the immunoreactive score. The median age of patients was 2 years (range: 0.4 to 9 y) with a M:F ratio of 1.9. Outcome information was available in 38 patients (alive=30, alive with disease=3, and deceased=5) with median follow-up of 60 months (range: 2 to 171 mo). EpCAM-IHC showed notable overexpression (immunoreactive score >4) in embryonal (89%) and crowded fetal (74%) in contrast to glandular (33%), well-differentiated fetal (32%), and small cell undifferentiated/blastemal (3%) components. Mesenchymal elements were negative. In summary, EpCAM-IHC is helpful to distinguish between epithelial components as it is progressively lost in the transition from embryonal to crowded fetal and into well-differentiated fetal histotypes. Its preferential expression among primitive HBs might have therapeutic and prognostic implications. The significance of its largely negative expression in small cell undifferentiated/blastema is interesting despite its presumed immaturity, deserving further studies.

Outcome of staging chest CT and identification of factors associated with lung metastasis in children with hepatoblastoma

OBJECTIVES

To evaluate the outcome of staging chest CT and to identify clinicoradiological factors predictive of lung metastasis in patients with hepatoblastoma based on the 2017 PRE-Treatment EXTent of tumor (PRETEXT) system.

METHODS

This bi-center study retrospectively identified patients diagnosed with hepatoblastoma between January 1998 and September 2019 in two tertiary hospitals. The primary outcome was the proportion of the patients who had lung metastasis at staging chest CT. The diagnostic accuracy of staging chest CT was calculated based on the 2017 PRETEXT criteria. The secondary outcome was the identification of factors predictive of lung metastasis using multivariable logistic regression.

RESULTS

In total, 123 patients (median age, 1 year; interquartile range, 0-4 years; 59 female) were included. Among those, 28% (35/123; 95% confidence interval [CI], 21-37%) had lung metastasis at staging chest CT. The overall accuracy of staging chest CT was 96.8%. The proportion of lung metastasis in patients with stage I, II, III, and IV was 0%, 24% (12 of 49; 95% CI, 14-38%), 23% (9 of 40; 95% CI, 12-38%), and 56% (14 of 25; 95% CI, 37-73%), respectively. Multifocality (adjusted odds ratio, 6.7; 95% CI, 2.7-17.5; p < .001) and male sex (adjusted odds ratio, 3.1; 95% CI, 1.2-8.6; p = .02) were associated with the presence of lung metastasis.

CONCLUSIONS

Twenty-eight percent of the patients with hepatoblastoma had lung metastasis at staging chest CT. Multifocality and male sex were predictive factors for lung metastasis on staging chest CT.

KEY POINTS

• The proportion of lung metastasis in patients with hepatoblastoma was 28%. • The overall accuracy of staging chest CT was 97% based on the 2017 PRETEXT system. • Hepatic tumor multifocality and male sex were predictors of lung metastasis.

Neuropilin-2 Is Associated With Increased Hepatoblastoma Cell Viability and Motility

The neuropilins NRP1 and NRP2 are multifunctional glycoproteins that have been implicated in several cancer-related processes including cell survival, migration, and invasion in various tumor types. Here, we examine the role of neuropilins in hepatoblastoma (HB), the most common pediatric liver malignancy. Using a combination of immunohistochemistry, RNA analysis and western blotting, we observed high level expression of NRP1 and NRP2 in 19 of 20 HB specimens and in a majority of human HB cell lines (HUH6 and five cell lines established from patient-derived xenografts) studied but not in normal hepatocytes. Silencing of NRP2 expression in HUH6 and HB-282 HB cells resulted in decreased cell viability, impaired cytoskeleton remodeling, and reduced cell motility, suggesting that NRP2 contributes to the malignant phenotype. We propose that neuropilins warrant further investigation as biomarkers of HB and potential therapeutic targets.

Imaging and Pathology Study of the Chemotherapy Regression Area of Hepatoblastoma - A Prospective Single-Center Study

Objective: The objective of this study is to determine the frequency of no residual cancer tissue in the chemotherapy regression area (CRA) of hepatoblastoma after preoperative chemotherapy and to measure the distance between the tumor capsule and the residual cancer nests. Methods: All the tissues in the CRAs of the resected specimens were excised. HE staining and immunohistochemical staining were performed to determine the frequency of residual cancer tissue in the CRA, and the distances between the residual cancer nests and the tumor capsule were measured. Results: A total of 30 patients were included in the study. The tumor volume decreased after chemotherapy by an average of 619 ml. Of the 30 patients, the CRAs of 18 still had residual cancer nests. The longest distance between the residual cancer nest and tumor capsule was 11.2 mm. Conclusions: After chemotherapy, 60% of patients still had residual cancer nests in CRAs, the furthest distance was 11.2 mm.

Hepatoblastoma: current knowledge and promises from preclinical studies

The survival rate for patients with metastatic hepatoblastoma (HB) is steadily increased in the last thirty years from 27% to 79%. These achievements result from accurate risk stratification and effective chemotherapy and surgical care. However, patients with poor prognosis require more effective therapies. Recent years have witnessed new insights on the biology of HB, setting the stage for molecular classification and new targets of therapy. We review here the molecular pathology of HB, focusing on the driver genes involved in the process of oncogenesis and the identification of novel targets. We also address the role of in vivo models in elucidating the mechanisms of development of this disease and the pre-clinical phase of new treatment modalities.

Intracellular localization of beta-catenin expression plays a possible prognostic role on the outcome of hepatoblastoma patients

PURPOSE

Wnt/Beta-catenin pathway plays an essential role in liver development and regeneration. Abnormal activation in this pathway leads to development of hepatoblastoma (HB). Although its importance has invoked attention, its prognostic role is debatable. We aimed to evaluate the significance of intracellular localization of beta-catenin (BC) expression in the outcome of hepatoblastoma patients.

METHODS

Medical records of HB patients between 2004 and 2018 were reviewed. Patients were grouped according to intracellular localization of BC expression by immunohistochemistry as being cytoplasmic or nuclear. Demographics, radiological images, PRETEXT classifications, vascular involvement, risk groups, chemotherapy responses, and survival rates were analyzed and compared between groups.

RESULTS

There were 41 patients. Thirteen patients were excluded for unavailability of records in four, negative/unclear BC expressions in seven. Cytoplasmic expression of BC was observed in 17 patients whereas 13 patients displayed nuclear expression. Demographics were similar in both groups. Cytoplasmic BC expression was associated with poor chemotherapy response (p = 0.001) and increased vascular involvement (p = 0.0162) requiring more extensive surgeries (p = 0.039).

CONCLUSION

Although the numbers are limited in our series, the intracellular localization of BC expression has been found to be a promising determining factor for hepatoblastoma prognosis. With larger patient series, more reliable results can be achieved.

Clinical and Pathological Study of Tumor Border Invasion-Is Narrow Resection Margin Acceptable in Hepatoblastoma Surgery?

Aim: We aim to study clinically and pathologically whether narrow resection margin (<1 cm) is acceptable in hepatoblastoma surgery.

Methods: A total of 42 patients who underwent surgery for hepatoblastoma were selected, and these patients were divided into two groups according to whether or not they underwent preoperative chemotherapy (CHT). The general characteristics of the patients were summarized, the resection margin distance was recorded, and the event-free survival rates were followed up. Pathologically, H&E staining and immunochemical staining were used to study the invasion distance outside the tumor capsule in the tumor border.

Results: Clinically, the event-free survival rates were not significantly different between the patients with wide resection margin (>1 cm) and narrow resection margin (<1 cm) of the two groups. Pathologically, the tumor of all 42 patients had capsules surrounding the tumor. Of the patients in Group 1 (without preoperative CHT), 9% (2/22) had micrometastatic cancer nests outside the capsule, and the farthest distance from the cancer nests to the capsule was 4.6 mm. Of the patients in Group 2 (with preoperative CHT), 75% (15/20) showed residual cancer nests in the paratumor liver tissue, and the farthest distance was 9.6 mm; three and two cases, respectively, showed extracapsular intravascular microtumorous thrombi.

Conclusion: Clinically and pathologically, narrow resection margin is acceptable in hepatoblastoma surgery.

Hepatoblastoma-The Evolution of Biology, Surgery, and Transplantation

The most common primary malignant liver tumor of childhood, hepatoblastoma has increased in incidence over the last 30 years, but little is still known about its pathogenesis. Discoveries in molecular biology provide clues but have yet to define targeted therapies. Disease-free survival varies according to stage, but is greater than 90% in favorable risk populations, in part due to improvements in chemotherapeutic regimens, surgical resection, and earlier referral to liver transplant centers. This article aims to highlight the principles of disease that guide current treatment algorithms. Surgical treatment, especially orthotopic liver transplantation, will also be emphasized in the context of the current Children's Oncology Group international study of pediatric liver cancer (AHEP-1531).