Prognostic stratification for children with hepatoblastoma: The SIOPEL experience

An indocyanine green-based liquid biopsy test for circulating tumor cells for pediatric liver cancer

BACKGROUND

Hepatoblastoma and HCC are the most common malignant hepatocellular tumors seen in children. The aim of this study was to develop a liquid biopsy test for circulating tumor cells (CTCs) for these tumors that would be less invasive and provide real-time information about tumor response to therapy.

METHODS

For this test, we utilized indocyanine green (ICG), a far-red fluorescent dye used clinically to identify malignant liver cells during surgery. We assessed ICG accumulation in cell lines using fluorescence microscopy and flow cytometry. For our CTC test, we developed a panel of liver tumor-specific markers, including ICG, Glypican-3, and DAPI, and tested it with cell lines and noncancer control blood samples. We then used this panel to analyze whole-blood samples for CTC burden with a cohort of 15 patients with hepatoblastoma and HCC and correlated with patient characteristics and outcomes.

RESULTS

We showed that ICG accumulation is specific to liver cancer cells, compared to nonmalignant liver cells, non-liver solid tumor cells, and other nonmalignant cells, and can be used to identify liver tumor cells in a mixed population of cells. Experiments with the ICG/Glypican-3/DAPI panel showed that it specifically tagged malignant liver cells. Using patient samples, we found that CTC burden from sequential blood samples from the same patients mirrored the patients' responses to therapy.

CONCLUSIONS

Our novel ICG-based liquid biopsy test for CTCs can be used to specifically detect and quantify CTCs in the blood of pediatric patients with liver cancer.

Management of Neonatal Hepatic Hemangiomas: A Single-Center Experience Focused on Challenging Cases

Background: Management of hepatic hemangioma (HH) in infancy ranges from close monitoring to surgical resection. We analyzed the clinical characteristics and outcomes of HH according to its treatment options, with particular focus on challenging cases. Methods: Data of patients diagnosed with HHs in their first year of life and followed up for at least 1 year were retrospectively reviewed and divided into treatment and observation groups. Serial imaging results, serum alpha-fetoprotein (AFP) levels, medications, and clinical outcomes were compared. The detailed clinical progress in the treatment group was reviewed separately. Results: A total of 87 patients (75 in the observation group and 12 in the treatment group) were included. The median HH size at the initial diagnosis and the maximum size were significantly larger in the treatment group than the observation group (2.2 [0.5-10.3] cm vs. 1.0 [0.4-4.0] cm and 2.1 [0.7-13.2] vs. 1.1 [0.4-4.0], respectively; all p < 0.05]. The median initial and last serum AFP levels were significantly higher in the treatment group than in the observation group (76,818.7 vs. 627.2 and 98.4 vs. 8.7, respectively; all p < 0.05). Serum AFP levels in both groups rapidly declined during the first 3 months of life and were almost undetectable after 6 months. Among the challenging cases, a large (14 × 10 × 6.5 cm sized) focal HH was successfully treated using stepwise medical-to-surgical treatment. Conclusions: Patients with large HH and mild symptoms can be treated using stepwise pharmacotherapy. More aggressive surgical treatment of tumors unresponsive to initial pharmacotherapy may help shorten the treatment period and improve outcomes.

Pediatric Hepatoblastoma After Neoadjuvant Chemotherapy: Diagnostic Performance of MR in Staging POSTTEXT and Vascular Involvement

BACKGROUND

The assessment of resectability after neoadjuvant chemotherapy of hepatoblastoma is dependent on Post-Treatment EXTENT of Disease (POSTTEXT) staging and its annotation factors P (portal venous involvement) and V (hepatic venous/inferior vena cava [IVC] involvement), but MR performance in assessing them remains unclear.

PURPOSE

To assess the diagnostic performance of contrast-enhanced MR imaging for preoperative POSTTEXT staging and diagnosing vascular involvement in terms of annotation factors P and V in pediatric hepatoblastoma following neoadjuvant chemotherapy.

STUDY TYPE

Retrospective.

SUBJECTS

Thirty-five consecutive patients (17 males, median age, 24 months; age range, 6-98 months) with proven hepatoblastoma underwent preoperative MR imaging following neoadjuvant chemotherapy.

FIELD STRENGTH/SEQUENCE

3.0 T; T2-weighted imaging (T2WI), T2WI with fat suppression, diffusion weighted imaging, radial stack-of-the-star/Cartesian 3D Dixon T1-weighted gradient echo imaging.

ASSESSMENT

Three radiologists independently assessed the POSTTEXT stages and annotation factors P and V based on the 2017 PRE/POSTTEXT system. The sensitivities and specificities were calculated for 1) diagnosing each POSTTEXT stage; 2) discrimination of stages III and IV (advanced) from those stages I and II (non-advanced) hepatoblastomas; and 3) annotation factors P and V. The combination of pathologic findings and surgical records served as the reference standard.

STATISTICAL TESTS

Sensitivity, specificity, Fleiss kappa test.

RESULTS

The sensitivity and specificity ranges for discriminating advanced from non-advanced hepatoblastomas were 73.3%-80.0% and 80.0%-90.0%, respectively. For annotation factor P, they were 66.7%-100.0% and 90.6%, respectively. For factor V, they were 75.0% and 67.7%-83.9%, respectively. There was excellent, substantial, and moderate agreement on POSTTEXT staging (Fleiss kappa = 0.82), factors P (Fleiss kappa = 0.64), and factors V (Fleiss kappa = 0.60), respectively.

DATA CONCLUSION

MR POSTTEXT provides reliable discrimination between advanced and non-advanced tumors, and MR has moderate to excellent specificity at identifying portal venous and hepatic venous/IVC involvement.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 3.

Mutational signature, cancer driver genes mutations and transcriptomic subgroups predict hepatoblastoma survival

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.

PIM Kinase Inhibition Attenuates the Malignant Progression of Metastatic Hepatoblastoma

Hepatoblastoma is the most common primary pediatric liver tumor. Children with pulmonary metastases at diagnosis experience survival rates as low as 25%. We have shown PIM kinases play a role in hepatoblastoma tumorigenesis. In this study, we assessed the role of PIM kinases in metastatic hepatoblastoma. We employed the metastatic hepatoblastoma cell line, HLM_2. PIM kinase inhibition was attained using PIM3 siRNA and the pan-PIM inhibitor, AZD1208. Effects of PIM inhibition on proliferation were evaluated via growth curve. Flow cytometry determined changes in cell cycle. AlamarBlue assay assessed effects of PIM kinase inhibition and cisplatin treatment on viability. The lethal dose 50% (LD50) of each drug and combination indices (CI) were calculated and isobolograms constructed to determine synergy. PIM kinase inhibition resulted in decreased HLM_2 proliferation, likely through cell cycle arrest mediated by p21. Combination therapy with AZD1208 and cisplatin resulted in synergy, potentially through downregulation of the ataxia-telangiectasia mutated (ATM) kinase DNA damage response pathway. When assessing the combined effects of pharmacologic PIM kinase inhibition with cisplatin on HLM_2 cells, we found the agents to be synergistic, potentially through inhibition of the ATM pathway. These findings support further exploration of PIM kinase inhibition as a therapeutic strategy for metastatic hepatoblastoma.

Navigating relapsed hepatoblastoma: Predictive factors and surgical treatment strategy

OBJECTIVE

Hepatoblastoma (HB) is the most common primary hepatic malignancy in childhood. Relapse occurs in more than 50% of high-risk patients with a high mortality due to ineffective salvage therapies. The purpose of this study is to identify risk factors for relapsed HB and predictors of survival in a single tertiary referral center.

METHODS

A retrospective chart review showed 129 surgically treated HB patients from October 2004 to July 2020. Of the cohort, 22 patients presented with relapsed HB. Relapse was defined as re-appearance of malignancy after 4 weeks of normalized AFP and disappearance of all tumors on imaging.

RESULTS

Patients with relapsed HB had a 5-year overall survival (OS) of 45.4% compared to 93.1% in those without relapse (p = 0.001). When comparing PRETEXT IV, microvascular invasion, metastatic disease, and age on multivariate logistic regression, only PRETEXT IV was an independent risk factor for relapsed HB with an OR of 2.39 (95% CI: 1.16-4.96; p = 0.019). Mixed epithelial and mesenchymal HB (12/19, 63.2%) was the most common histology of primary tumors while pure epithelial HB (13/15, 86.6%) was the most common relapsed histology. Combination of surgical and medical therapy for relapsed disease was predictive of survival with an HR of 16.3 (95% CI: 1.783-149.091; p = 0.013) compared to only chemotherapy.

CONCLUSIONS

This study demonstrates that PRETEXT IV staging is an independent predictor of relapsed disease. The most common relapsed histology was epithelial, suggesting a potential selection or resistance of this component. Surgical resection is a critical component of multimodal therapy for relapsed HB.

Surgical Management and Outcomes of Patients with Multifocal Hepatoblastoma

OBJECTIVE

To compare the outcomes of patients with multifocal hepatoblastoma (HB) treated at our institution with either orthotopic liver transplant (OLTx) or hepatic resection to determine outcomes and risk factors for recurrence.

BACKGROUND

Multifocality in HB has been shown to be a significant prognostic factor for recurrence and worse outcome. The surgical management of this type of disease is complex and primarily involves OLTx to avoid leaving behind microscopic foci of disease in the remnant liver.

METHODS

We performed a retrospective chart review on all patients <18 years of age with multifocal HB treated at our institution between 2000 and 2021. Patient demographics, operative procedure, post-operative course, pathological data, laboratory values, short- and long-term outcomes were analyzed.

RESULTS

A total of 41 patients were identified as having complete radiologic and pathologic inclusion criteria. Twenty-three (56.1%) underwent OLTx and 18 (43.9%) underwent partial hepatectomy. Median length of follow-up across all patients was 3.1 years (IQR 1.1-6.6 years). Cohorts were similar in rates of PRETEXT designation status identified on standardized imaging re-review (p = .22). Three-year overall survival (OS) estimate was 76.8% (95% CI: 60.0%-87.3%). There was no difference in rates of recurrence or overall survival in patients who underwent either resection or OLTx (p = .54 and p = .92 respectively). Older patients (>72 months), patients with a positive porta hepatis margin, and patients with associated tumor thrombus experienced worse recurrence rates and survival. Histopathology demonstrating pleomorphic features independently associated with worse rates of recurrence.

CONCLUSIONS

Through proper patient selection, multifocal HB was adequately treated with either partial hepatectomy or OLTx with comparable outcome results. HB with pleomorphic features, increased patient age at diagnosis, involved porta hepatis margin on pathology, and the presence of associated tumor thrombus may be associated with worse outcomes regardless of the local control surgery offered.

LEVEL OF EVIDENCE

III.

Children's Oncology Group's 2023 blueprint for research: Liver tumors

Liver tumors account for approximately 1%-2% of all pediatric malignancies, with the two most common tumors being hepatoblastoma (HB) and hepatocellular carcinoma (HCC). Previous Children's Oncology Group studies have meaningfully contributed to the current understanding of disease pathophysiology and treatment, laying groundwork for the ongoing prospective international study of both HB and HCC. Future work is focused on elucidating the biologic underpinnings of disease to support an evolution in risk categorization, advancements in the multidimensional care required to treat these patients, and the discovery of novel therapies.

An indocyanine green-based liquid biopsy test for circulating tumor cells for pediatric liver cancer

Background and Aims

Hepatoblastoma (HB) and hepatocellular carcinoma (HCC) are the most common malignant hepatocellular tumors seen in children. The aim of this work was to develop a liquid biopsy test for circulating tumor cells (CTCs) for these tumors that would be less invasive and provide information about the real-time state of tumors in response to therapies.

Methods

For this test, we utilized indocyanine green (ICG), a far-red fluorescent dye that is used clinically to identify malignant liver cells in the body during surgery. We assessed ICG accumulation in cell lines with fluorescence microscopy and flow cytometry. For our CTC test, we developed a panel of liver tumor-specific markers, ICG, Glypican-3 (GPC3), and DAPI and tested this panel with cell lines and non-cancer control blood samples. We then used this panel to analyze whole blood samples for CTC burden with a cohort of 14 HB and HCC patients and correlated with patient characteristics and outcomes.

Results

We showed that ICG accumulation is specific to liver cancer cells, compared to non-malignant liver cells, non-liver solid tumor cells, and non-malignant cells and can be used to identify liver tumor cells in a mixed population of cells. Experiments with the ICG/GPC3/DAPI panel showed that it specifically tagged malignant liver cells. With patient samples, we found that CTC burden from sequential blood samples from the same patients mirrored the patients' responses to therapy.

Conclusions

Our novel ICG-based liquid biopsy test for CTCs can be used to specifically count CTCs in the blood of pediatric liver cancer patients.

Impact and implications

This manuscript represents the first report of circulating tumor cells in the blood of pediatric liver cancer patients. The novel and innovative assay for CTCs shown in this paper will facilitate future work examining the relationship between CTC numbers and patient outcomes, forming the foundation for incorporation of liquid biopsy into routine clinical care for these patients.

Graphical abstract

Overview of novel liquid biopsy test for circulating tumor cells for pediatric liver cancer. Figure made with Biorender.

Lung and right atrial metastases from hepatoblastoma in children: A case series and literature review

Hepatoblastoma (HB) in children with both lung and right atrial metastases is an unusual situation. The therapy for these cases is challenging and the prognosis is not good. We present three children with HB showing both lung and right atrial metastases and who underwent surgery and received preoperative/postoperative adjuvant-combined chemotherapy to achieve complete remission. Therefore, HB with lung and right atrial metastases could have a good prognosis through active and multidisciplinary treatment.

Strategy for hepatoblastoma with major vascular involvement: A guide for surgical decision-making

BACKGROUND

Surgical management of tumor thrombus extending to the major vascular system for children with hepatoblastoma is challenging and insufficiently discussed.

METHODS

We conducted a retrospective review of hepatoblastoma with tumor thrombus extending to the major vascular system (inferior vena cava, 3 hepatic veins, and portal vein trunk) treated at our center between May 2010 and June 2021. We describe our preoperative assessment, surgical strategies, and outcomes.

RESULTS

We identified 9 patients (median age at the diagnosis: 3.4 years). All patients received chemotherapy before liver surgery. At the time of the diagnosis, tumor thrombus extended to the portal vein trunk (n = 6), inferior vena cava (n = 3), and 3 hepatic veins (n = 2). Among the 9 patients, 4 underwent liver resection. Liver transplantation was performed in 5 patients. The inferior vena cava wall was circumferentially resected for tumor removal in 1 patient and partially resected in 2 patients. One patient underwent liver transplantation using veno-venous bypass. Patients with tumor thrombus extending to the portal vein trunk were more likely to be managed by liver transplantation in comparison to those with tumor thrombus spreading to the inferior vena cava. The median follow-up period was 5.5 years. One patient underwent transhepatic balloon dilatation for biliary stricture after liver resection. Tumor recurrence was seen in 3 patients (33.3%; lung, n = 2; lymph node and liver, n = 1). No patients died during the follow-up period.

CONCLUSION

Surgical intervention for pediatric hepatoblastoma with tumor thrombus extending into the major vascular system is safe, feasible, and achieves excellent outcomes.

Neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio as predictive markers in hepatoblastoma

Background

The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been presented to be a prognostic indicator in several cancers. We were supposed to evaluate the prognostic role of such inflammatory markers in hepatoblastoma (HB).

Methods

Total of 101 children, diagnosed with hepatoblastoma between January 2010 and January 2018, were enrolled before treatment in the study. The clinicopathological parameters, and outcomes were collected through laboratory analyses and patient follow-up. The association between NLR, PLR, and clinicopathological characters were analyzed with Wilcoxon test, Chi-Squared test, Kaplan-Meier, Log-rank and Cox regression analyses.

Results

NLR and PLR were significantly elevated in HB patients (P < 0.001), and related to age (P < 0.001), risk stratification system (P < 0.001), and pretreatment extent of disease (P < 0.0001). NLR was significantly related to alpha-fetoprotein (P = 0.034) and lactate dehydrogenase (P = 0.026). The 3-year overall survival (OS) and event-free survival (EFS) were poor in the high-NLR group (OS: 44.3% vs. 90.3%, P < 0.0001, EFS: 38.6% vs. 80.6%, P = 0.0001). The 3-year OS and EFS were poor in the high-PLR group (OS: 49.1% vs. 68.8%, P = 0.016, EFS: 39.6% vs. 64.6%, P = 0.0117). The multivariate analysis suggested that NLR (HR: 11.359, 95% CI: 1.218-105.947; P = 0.033) and risk stratification (HR: 44.905, 95% CI: 2.458-820.36; P = 0.01), were independent predictors of OS.

Conclusion

Our research showed that elevated NLR and PLR were the poor prognostic factors in HB patients before treatment. The NLR was an independent prognostic factor for OS.

Outcome and morbidity of liver surgery in children: a single-centre, 47-year experience

Background

The outcome and survival of children with both benign and malignant liver tumours, over a 47-year period was recorded at The National Paediatric Cancer Centre, Our Lady’s Children’s Hospital (OLCHC), Crumlin. The retrospective study documents the impact of improved chemotherapy, multidisciplinary team approach and specific paediatric hepatobiliary surgical training on morbidity, outcome and survival.

Methods

A retrospective review of the hospital records of all children who presented with a primary liver tumour (benign or malignant) or a primary malignancy significantly involving the liver was undertaken. A review of the management of all such patients at OLCHC, between 1964 and 2011 was performed. This retrospective study reports on two distinct periods, group 1 (1964–1990, N = 21 patients, previously reported) and group 2 (1994–2011, N = 33). Follow-up for all group 2 patients ended in November 2014.

Results

A marked difference in survival was noted between the groups with 91% overall survival in group 2 patients as compared to 28% in group 1. Significant complications were documented in group 1 but were uncommon in group 2.

Conclusion

The improvement in mortality and morbidity reflects improved staging and chemotherapy in all patients with a malignant disease but also improved surgical strategies and multi-disciplinary team management (MDT). Specialist training in liver surgery had a significant impact on post-operative morbidity. The results suggest that in certain circumstances, rare and complex liver surgery may be performed in small centres if the necessary supports and experience co-exist.

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.

Diagnostic yield and accuracy of paediatric image-guided fine needle aspiration biopsy of deep organ tumours

Background

Paediatric tumour cytological diagnosis by image-guided fine needle aspiration biopsy (FNAB) with rapid on-site evaluation (ROSE) has not gained wide acceptance despite increasing publications advocating the procedure.

Objective

The primary aim was an audit of the diagnostic yield and accuracy of paediatric image-guided FNAB with ROSE at a single institution. Evaluation of safety was a secondary aim.

Method

Details of consecutive cases of paediatric image-guided FNAB with ROSE for suspected non-benign deep-seated lesions performed from 01 January 2014 to 30 April 2020 were retrieved from the institutional radiology and laboratory databases. Diagnostic yield and accuracy were evaluated using clinico-pathological-radiological correlation and/or subsequent histological specimen diagnosis correlation. Complications and the frequency of key radiological features potentially affecting yield and accuracy were described.

Results

Of 65 cases retrieved, cytology showed malignancy in 52, benign features in five and one indeterminate diagnosis; seven samples were insufficient for cytological assessment. Of the 65 cases, 58 had subsequent formal histological diagnosis. The overall diagnostic yield was 98.5%, with 94.5% sensitivity, 100.0% specificity, 100.0% positive predictive value, 75.0% negative predictive value and 95.3% diagnostic accuracy. All cases (n = 26) demonstrating restricted diffusion on MRI yielded adequate samples and cyto-histopathological correlation.

Conclusion

Paediatric image-guided FNAB with ROSE has a relatively high diagnostic yield, sensitivity, specificity, positive predictive value and accuracy in the diagnosis of deep-seated tumours. The relatively low negative predictive value may reflect insufficient samples obtained from cystic and/or benign lesions. Sampling from areas of restricted MRI diffusion may enhance diagnostic yield.

Integration of a dedicated management protocol in the care of pediatric liver cancer: From specialized providers to complication reduction

INTRODUCTION

Up to a third of children undergoing partial hepatectomy for primary hepatic malignancies experience at least one perioperative complication, with a presumed deleterious effect on both short- and long-term outcomes. We implemented a multidisciplinary treatment protocol in the management of these patients in order to improve complication rates following partial hepatectomy.

METHODS

A retrospective chart review was completed for all patients < 18 years of age who underwent liver resection at our institution between 2002 and 2019 for primary hepatic cancer. Demographic, intraoperative, postoperative, pathologic, and outcome data were analyzed for perioperative complications using the CLASSIC and Clavien-Dindo (CD) scales, event-free survival (EFS) and overall survival (OS).

RESULTS

A total of 73 patients were included in the analysis with 33 prior-to and 40 after dedicated provider protocol implementation. Perioperative complication rates decreased from 52% to 20% (p = 0.005) with major complications going from 18% to 10% (p = 0.31). On multivariable logistic regression, protocol implementation was associated with a reduction in any (OR 0.29 [95% CI 0.09 - 0.89]) but not major complications. On multivariate cox models, post protocol implementation was associated with improved event free survival (EFS) (HR 0.19 (0.036 - 0.195). Among patients with a diagnosis of hepatoblastoma (n = 62), the occurrence of a major perioperative complication was associated with a worse EFS (HR=5.45, p = 0.03) on multivariate analysis, however this did not translate into an impact on overall survival.

CONCLUSIONS

Our results demonstrate that, for children with primary liver malignancies, a dedication of patients to high-volume surgeons can improve rates of complications of liver resections and may improve the oncological outcome of hepatoblastoma.

Prognostic implication of serum Alpha-fetoprotein response to neoadjuvant chemotherapy in Hepatoblastoma patients

Objective: This retrospective study aims to identify the early changes in serum alpha-fetoprotein levels (AFP) and their correlation with the survival outcome of hepatoblastoma patients. Materials and Methods: A total of 68 patients presented to the children's cancer hospital Egypt and the national cancer institute from January 2013 till June 2016 were included in this study. Results: AFP level was measured post-cycle 2 in 60 patients; 44 (73.3%) patients showed a decline in AFP level by >1 log reduction. The 3-year EFS was 75.6% for patients with >1 log reduction in AFP level, compared with 36.5% for those with <1 log reduction (p=0.010). The 3-year OS’ for patients with >1 and <1 log reduction in AFP level were 80.4% and 39.4%, respectively (p=0.005). On multivariate analysis; Patients with AFP log reduction< 1 had worse OS/EFS with hazards ratio (HR): 3.9 and 95% confidence interval (CI):1.4-11.2, p value=0.011 and HR: 3.2 and 95% CI: 1.3-8.9, p value=0.013 respectively. Conclusion: The ease of AFP determination makes it a valuable tool that could be routinely used to evaluate the therapeutic efficacy and predict the survival outcome.

Small Cell Undifferentiated Histology Does Not Adversely Affect Outcome in Hepatoblastoma: A Report From the Children's Oncology Group (COG) AHEP0731 Study Committee

PURPOSE

Small cell undifferentiated (SCU) histology in hepatoblastoma (HB) tumors has historically been associated with a poor prognosis. Tumors from patients enrolled on Children's Oncology Group (COG) study AHEP0731 underwent institutional and central pathologic review for identification of SCU histology.

PATIENTS AND METHODS

Patients with SCU histology identified at the local treating institution who had otherwise low-risk tumors were upstaged to the intermediate-risk treatment stratum, whereas those only identified by retrospective central review were treated per the local institution as low-risk. Patients with otherwise intermediate- or high-risk tumors remained in that treatment stratum, respectively. Central review was to be performed for all tissue samples obtained at any time point. Treatment was per local review, whereas analysis of outcome was based on central review.

RESULTS

Thirty-five patients had some elements (1%-25%) of SCU identified on central review of diagnostic specimens. All but two patient tissue sample retained nuclear INI1 expression. The presence of SCU histology did not correlate with age, alpha-fetoprotein level at diagnosis, or sex. The presence of SCU did not affect event-free survival (EFS). EFS at 5 years for patients with low-risk, intermediate-risk, and high-risk with SCU HB was 86% (95% CI, 33 to 98), 81% (95% CI, 57 to 92), and 29% (95% CI, 4 to 61), respectively, compared with EFS at 5 years for patients without SCU enrolled with low-risk, intermediate-risk, and high-risk of 87% (95% CI, 72 to 95), 88% (95% CI, 79 to 94), and 55% (95% CI, 32 to 74; P = .17), respectively.

CONCLUSION

The presence of SCU histology in HB does not appear to adversely affect outcome. Future studies should be able to treat patients with SCU HB according to risk stratification without regard to the presence of SCU histology.

A Systematic Review and Meta-Analysis of Malignant Rhabdoid and Small Cell Undifferentiated Liver Tumors: A Rational for a Uniform Classification

Simple Summary

Malignant rhabdoid tumors of the liver are very rare pediatric liver tumors with a devastating prognosis. It is currently unclear which histological subtypes of pediatric liver tumors belong to this entity and how these tumors should be treated. In this systematic review with meta-analysis, we analyzed all reports on pediatric patients with malignant rhabdoid liver tumors, but also with so-called small cell undifferentiated liver tumors. This is another rare liver tumor subtype that has recently been regarded to belong to the entity of rhabdoid tumors by some authors. The main result of this study is that these two tumor subtypes show large overlap on several levels and even mixtures of both histological patterns have been documented. Our meta-analysis provides an evidence base for the recommendation to classify these two tumor subtypes as one entity. We showed that treatment of these tumors with hepatoblastoma directed chemotherapy is ineffective and that a therapy with chemotherapy regimens initially applied for soft tissue sarcoma is associated with a significantly better survival. This study represents the highest level of evidence available for these rare liver tumors.

Abstract

Background: Rhabdoid liver tumors in children are rare and have a devastating prognosis. Reliable diagnosis and targeted treatment approaches are urgently needed. Immunohistochemical and genetic studies suggest that tumors formerly classified as small cell undifferentiated hepatoblastoma (SCUD) belong to the entity of malignant rhabdoid tumors of the liver (MRTL), in contrast to hepatoblastomas with focal small cell histology (F-SCHB). This may have relevant implications on therapeutic approaches. However, studies with larger cohorts investigating the clinical relevance of the histological and genetic similarities for patients are lacking. Purpose: To analyze possible similarities and differences in patient characteristics, tumor biology, response to treatment, and clinical course of patients with MRTL, SCUD and F-SCHB. Applied therapeutic regimens and prognostic factors are investigated. Methods: A systematic literature search of MEDLINE, Web of Science, and CENTRAL was performed for this PRISMA-compliant systematic review. All studies of patients with MRTL, SCUD and F-SCHB that provided individual patient data were included. Demographic, histological, and clinical characteristics of the three subgroups were compared. Overall survival (OS) was estimated with the Kaplan–Meier method and prognostic factors investigated in a multivariable Cox regression model. Protocol registered: PROSPERO 2021 CRD42021258760. Results: Fifty-six studies with a total of 118 patients were included. The two subgroups MRTL and SCUD did not differ significantly in baseline patient characteristics. However, heterogenous diagnostic and therapeutic algorithms were applied. Large histological and clinical overlap between SCUD and MRTL could be shown. Two-year OS was 22% for MRTL and 13% for SCUD, while it was significantly better in F-SCHD (86%). Chemotherapeutic regimens for hepatoblastoma proved to be ineffective for both SCUD and MRTL, but successful in F-SCHB. Soft tissue sarcoma chemotherapy was associated with significantly better survival for MRTL and SCUD, but was rarely applied in SCUD. Patients who did not undergo surgical tumor resection had a significantly higher risk of death. Conclusions: While F-SCHB is a subtype of HB, SCUD should be classified and treated as a type of MRTL. Surgical tumor resection in combination with intensive, multi-agent chemotherapy is the only chance for cure of these tumors. Targeted therapies are highly needed to improve prognosis. Currently, aggressive regimens including soft tissue sarcoma chemotherapy, extensive resection, radiotherapy or even liver transplantation are the only option for affected children.

Diagnostic and Prognostic Value of miRNAs in Hepatoblastoma: A Systematic Review With Meta-Analysis

Background and aim: Increasing evidence has revealed the valuable diagnostic and prognostic applications of dysregulated microRNAs (miRNAs) in hepatoblastoma (HB), the most common hepatic malignancy during childhood. However, these results are inconsistent and remain to be elucidated. In the present study, we aimed to systematically compile up-to-date information regarding the clinical value of miRNAs in HB. Methods: Articles concerning the diagnostic and prognostic value of single miRNAs for HB were searched from databases. The sensitivity (SEN), specificity (SPE), positive and negative likelihood ratios (PLR and NLR), diagnostic odds ratio (DOR), area under the curve (AUC), and hazard ratios (HRs) were separately pooled to explore the diagnostic and prognostic performance of miRNA. Subgroup and meta-regression analyses were further carried out only in the event of heterogeneity. Results: In all, 20 studies, involving 264 HB patients and 206 healthy individuals, met the inclusion criteria in the 6 included literature articles. For the diagnostic analysis of miRNAs in HB, the pooled SEN and SPE were 0.76 (95% CI: 0.72-0.80) and 0.75 (95% CI: 0.70-0.80), respectively. Moreover, the pooled PLR was 2.79 (95% CI: 2.12-3.66), NLR was 0.34 (95% CI: 0.26-0.45), DOR was 10.24 (95% CI: 6.55-16.00), and AUC was 0.83, indicating that miRNAs had moderate diagnostic value in HB. For the prognostic analysis of miRNAs in HB, the abnormal expressions of miR-21, miR-34a, miR-34b, miR-34c, miR-492, miR-193, miR-222, and miR-224 in patients were confirmed to be associated with a worse prognosis. The pooled HR was 1.74 (95% CI: 1.20-2.29) for overall survival and 1.74 (95% CI: 1.31-2.18) for event-free survival, suggesting its potential as a prognostic indicator for HB. Conclusion: To the best of our knowledge, this is the first comprehensive systematic review and meta-analysis that examines the diagnostic and prognostic role of dysregulated miRNAs in HB patients. The combined meta-analysis results supported the previous individual finds that miRNAs might provide a new, noninvasive method for the diagnostic and prognostic analyses of HB.

Integrative Analysis of DNA Methylation and Gene Expression Profiling Data Reveals Candidate Methylation-Regulated Genes in Hepatoblastoma

Purpose

This study aimed to identify novel methylation-regulated genes as diagnostic biomarkers and therapeutic targets for hepatoblastoma (HB).

Materials and Methods

The DNA methylation data of 19 HB tumor samples and 10 normal liver samples from the GSE78732 dataset and gene expression profiling data of 53 HB tumor samples and 14 normal liver samples from the GSE131329 dataset and 31 HB tumor samples and 32 normal liver samples from the GSE133039 dataset were downloaded form the Gene Expression Omnibus database. Next, differentially methylated genes (DMGs) and differentially expressed genes (DEGs) were identified. Venn diagrams were used to identify methylation-regulated genes. The VarElect online tool was selected to identify key methylation-regulated genes, and a protein–protein interaction (PPI) network was constructed to show the interactions among key methylation-regulated genes and DEGs. Finally, Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were performed to investigate the potential regulatory mechanisms of key methylation-regulated genes.

Results

A total of 457 DMGs and 1597 DEGs were identified between the HB and normal liver samples. After DMGs and DEGs overlapping, 22 hypomethylated and upregulated genes and 19 hypermethylated and downregulated genes in HB were screened. Survival analysis revealed that 13 methylation-regulated genes were associated with the prognosis of liver cancer. Moreover, SPP1, UHRF1, and HEY1 were selected as the key DNA methylation-regulated genes. The PPI network revealed that all of them could affect TP53, while both UHRF1 and HEY1 could influence BMP4. Enrichment analysis suggested that the DEGs were involved in TP53-related pathways, including the cell cycle and p53 signaling pathway. Finally, SPP1, UHRF1, and HEY1 were hypomethylated and upregulated in the HB samples compared with those in the normal liver samples.

Conclusion

SPP1, UHRE1, and HEY1 may play important roles in HB and be used as biomarkers for its diagnosis and treatment.

Factors influencing recurrence after complete remission in children with hepatoblastoma: A 14-year retrospective study in China

Objective

After a complete remission to treatment for hepatoblastoma, some children still have recurrence. We identified and explored the factors that influence recurrence after complete remission in a retrospective study.

Methods

Of 197 children with hepatoblastoma, 140 (71.1%) achieved initial complete remission and were enrolled in factor analysis. Variables consisted of age, sex, PRE-Treatment EXTent of tumor (PRETEXT) stage, pathologic type, metastatic disease, serum alpha-fetoprotein level, vascular involvement, and surgical margin status. We employed univariate and multivariate analyses to assess the relationship between each factor and tumor recurrence.

Results

Of 140 children who achieved initial complete remission, 42 (30%) had recurrent hepatoblastoma. The 5-year overall survival rates for the non-recurrence and recurrence group were 99.0% and 78.6%, respectively. The overall 1-year, 3-year, and 5-year recurrence-free survival (RFS) rates were 77.8%, 69.8%, and 69.8%, respectively. All recurrences occurred within 2 years from complete remission. The RFS rate was significantly higher in children younger than 3 years and in those with mixed pathological type, PRETEXT II and III, without metastatic disease, without vascular involvement, and microscopic negative margin than in that of children older than 3 years, with epithelial pathological type, PRETEXT IV, metastatic disease, vascular involvement, and macroscopic positive margin (P < 0.001, = 0.020, < 0.001, = 0.004, = 0.002, and < 0.001, respectively). The independent risk factors for recurrence after complete remission were age ≥3 years, PRETEXT IV, and metastatic disease (P < 0.05).

Conclusion

Age, PRETEXT stage, metastatic disease, vascular involvement, pathologic type, and surgical margin status might be associated with recurrent hepatoblastoma after complete remission; meanwhile, age ≥3 years, PRETEXT IV, and metastatic disease are independent risk factors of recurrence. Further research is needed on the causes of tumor recurrence, which may improve the long-term outcomes of children with hepatoblastoma.

Living donor liver transplantation for hepatic malignancies in children

BACKGROUND

Living donor liver transplantation is a treatment option for unresectable hepatic tumors in children.

METHODS

We enrolled 45 living donor transplantations performed between 1993 and 2018 for liver malignacies, which included hepatoblastoma (n = 33), hepatocellular carcinoma (n = 10), hepatic angiosarcoma (n = 1), and rhabdomyosarcoma (n = 1).

RESULTS

No mortality or major morbidities were encountered in any donor, and the complication rate was 9%. In the hepatoblastoma group, 5-year overall and event-free survival rate in recipients was 87.4% and 75.8%, respectively, and mortality was significantly higher in patients after rescue transplantation (p = .001). Inferior vena cava replacement in these recipients appeared to be associated with reduced mortality (p = .034), but this was not confirmed when rescue patients were excluded (p = .629). In hepatocellular carcinoma group, both 5-year overall and event-free survival rates were 75.4% each, and invasion of hepatic veins was significantly associated with increased risk of recurrence and death (p = .028). The patient with rhabdomyosarcoma died from EBV-induced lymphoma 2 months after transplantation. The patient with angiosarcoma was in complete remission at the last follow-up. Overall, 5-year graft survival rate was 81.3%, and one patient underwent re-transplantation due to chronic rejection.

CONCLUSIONS

Pediatric oncological liver transplantation has become a key player in the management of malignancies with cancer cure in 84% of patients in this series. Living donor liver transplantation for pediatric recipients with unresectable tumors might be a beneficial surgical option, which is technically safe for donors and recipients, thus, allowing timely planning according to chemotherapy protocols.

Surgical Resection of Hepatoblastoma: Factors Affecting Local Recurrence

INTRODUCTION

 This study aimed to investigate potential factors contributing to local recurrence after surgical resection of hepatoblastoma (HB).

MATERIALS AND METHODS

 This retrospective study involving all patients with HB who underwent nontransplant surgery at our tertiary center between July 2007 and July 2018. Data were analyzed regarding microscopic surgical resection margin, tumor multifocality and extracapsular tumor extension in correlation with local recurrence. These relations were assessed by logistic regression.

RESULTS

 The study included 133 patients with a median age of 1.3 years (range: 0.5-12.8 years). They were classified into 99 cases (74.44%) standard risk and 34 cases (25.56%) high risk. Delayed surgical resection was adopted in all patients. Follow-up to July 2019 revealed that 23 patients (23/133, 17.3%) developed local recurrence, whereas the remaining 110 were locally disease free. Microscopic positive margin (R1) was detected in 29 patients, 8 of them had local recurrence (p = 0.097). Regarding tumor multifocality, there were 12 patients who had multifocal lesions, 3 of them developed local recurrence (p = 0.459). Forty-four patients had extracapsular tumor extension in their pathological reports, 12 of them had local recurrence (p = 0.032).

CONCLUSION

 Extracapsular tumor extension was a significant prognostic factor of local recurrence after surgical resection of HB. R1 margin does not necessarily require a second resection, and it could achieve accepted results when combined with adjuvant platinum-based chemotherapy. However, patients who are not eligible for surgical resection must be transferred for primary transplantation to obtain favorable outcome.

Histomorphological patterns of hepatoblastoma in a tertiary care hospital

Background

Hepatoblastoma (HB), rare malignancy in itself, is the most common primary liver tumor in children. Most common presenting features are abdominal distension or abdominal mass. Several patterns are associated with HB with different prognosis. Furthermore, some patterns have overlapping features with other childhood tumors.

Aims and Objectives

The aim of this study is to discuss various patterns of HB which we came across in a tertiary care hospital during our study. H and E slides were reviewed with respect to different patterns, postchemotherapy changes including extramedullary hematopoiesis, necrosis, osteoid metaplasia, necrosis, and fibrosis.

Conclusion

Different patterns of HB should be kept in mind by the pathologists to avoid any misdiagnosis.

Role of anticoagulation in the management of tumor thrombus: A 10-year single-center experience

BACKGROUND

Children with cancer diagnosis are overall at a higher risk of thrombosis. For a newly diagnosed blood clot, patients are commonly started on anticoagulants to prevent further extension and embolization of the clot. In the rare instance that a pediatric patient has a tumor thrombus, role of anticoagulation is less clear.

PROCEDURE/METHODS

Patients under 21 years of age with a finding of tumor thrombus on imaging from 2010 to 2020 at Texas Children's Hospital were identified and their medical records were reviewed.

RESULTS

A total of 50 patients were identified. Most thrombi were incidental findings at diagnosis; however, two patients presented with pulmonary embolism (PE). Inferior vena cava extension was noted in 36% of the patients, and 24% patients had an intracardiac tumor thrombus. Anticoagulation was initiated in 10 patients (20%). There was no difference in the rate of bland thrombus formation and/or embolization in patients who did or did not receive anticoagulation. However, three of the six patients with asymptomatic tumor thrombus who were started on anticoagulation had bleeding complications compared to only two patients in the no anticoagulation cohort (p < .05).

CONCLUSION

Children with intravascular extension of solid tumors were not commonly started on anticoagulation at the time of diagnosis, irrespective of the extent of tumor thrombus. Furthermore, we observed a significant trend toward higher incidence of bleeding complications after initiation of anticoagulation for asymptomatic tumor thrombus. There is inadequate evidence at this time to support routine initiation of anticoagulation in pediatric patients with intravascular extension of solid tumors.

The Genetic Changes of Hepatoblastoma

Hepatoblastoma is the most common malignant liver cancer in childhood. The etiology of hepatoblastoma remains obscure. Hepatoblastoma is closely related to genetic syndromes, hinting that hepatoblastoma is a genetic predisposition disease. However, no precise exposures or genetic events are reported to hepatoblastoma occurrence. During the past decade, significant advances have been made in the understanding of etiology leading to hepatoblastoma, and several important genetic events that appear to be important for the development and progression of this tumor have been identified. Advances in our understanding of the genetic changes that underlie hepatoblastoma may translate into better patient outcomes. Single nucleotide polymorphisms (SNPs) have been generally applied in the research of etiology's exploration, disease treatment, and prognosis assessment. Here, we reviewed and discussed the molecular epidemiology, especially SNPs progresses in hepatoblastoma, to provide references for future studies and promote the study of hepatoblastoma's etiology.

Sarcopenia is a prognostic outcome marker in children with high-risk hepatoblastoma

BACKGROUND

Children with hepatoblastoma (HB) are at risk of sarcopenia due to immobility, chemotherapy, and malnutrition. We hypothesized that children with HB have a low preoperative total psoas muscle area (tPMA), reflecting sarcopenia, which negatively impacts outcome.

PROCEDURE

Retrospective study of children (1-10 years) with hepatoblastoma treated at a large university children's hospital from 2009 to 2018. tPMA was measured as the sum of the right and left psoas muscle area (PMA) at intervertebral disc levels L3-4 and L4-5. z-Scores were calculated using age- and gender-specific reference values and were compared to anthropometric measurements, clinical variables, and outcomes. Sarcopenia was defined as a tPMA z-score below -2.

RESULTS

Thirty-three children were included. Mean tPMA z-score was -2.18 ± 1.08, and 52% were sarcopenic. A poor correlation between tPMA and weight was seen (r = 0.35; confidence interval [CI] 0.01, 0.62; P = .045), and most children had weights within the normal range (mean z-score -0.55 ± 1.39). All children categorized as high risk with relapse (n = 5/12) were sarcopenic before surgery. Relapse was significantly higher in the high-risk sarcopenic group compared to the nonsarcopenic group (P = .008). The change in tPMA z-score 1-4 months after surgery did not improve in patients with relapse, but did improve in 75% of children without relapse.

CONCLUSIONS

The majority of children with HB were sarcopenic prior to surgery. Especially in children with high-risk hepatoblastoma, sarcopenia is an additional risk factor for relapse. Large multicenter studies are needed to confirm these preliminary results.

Preoperative Assessment for Event-Free Survival With Hepatoblastoma in Pediatric Patients by Developing a CT-Based Radiomics Model

Objective: To explore a CT-based radiomics model for preoperative prediction of event-free survival (EFS) in patients with hepatoblastoma and to compare its performance with that of a clinicopathologic model.

Patients and Methods: Eighty-eight patients with histologically confirmed hepatoblastoma (mean age: 2.28 ± 2.72 years) were recruited from two institutions between 2002 and 2019 for this retrospective study. They were divided into a training cohort (65 patients from institution A) and a validation cohort (23 patients from institution B). Radiomics features were extracted manually from pretreatment CT images in the portal venous (PV) phase. The least absolute shrinkage and selection operator (LASSO) Cox regression model was applied to construct a “radiomics signature” and radiomics score (Rad-score) for EFS prediction. Then, a nomogram incorporating the Rad-score, updated staging system, and significant variables of clinicopathologic risk (age, alpha-fetoprotein (AFP) level, histology subtype, tumor diameter) as the radiomic model, clinicopathologic model, and combined clinicopathologic-radiomic model were built for EFS estimation in the training cohort, the performance of which was assessed in an external-validation cohort with respect to clinical usefulness, discrimination, and calibration.

Results: Nine survival-relevant features were selected for a radiomics signature and Rad-score building. Multivariable analysis revealed that histology subtype (P = 0.01), PV (P = 0.001) invasion, and metastasis (P = 0.047) were independent risk factors of EFS. Patients were divided into low- and high-risk groups based on the Rad-score with a cutoff of 0.08 according to survival outcome. The radiomics signature-incorporated nomogram showed good performance (P < 0.001) for EFS estimation (C-Index: 0.810; 95% CI: 0.738–0.882), which was comparable with that of the clinicopathological model for EFS estimation (C-Index: 0.81 vs. 0.85). The radiomics-based nomogram failed to show incremental prognostic value compared with that using the clinicopathologic model. The combined model (radiomics signature plus clinicopathologic parameters) showed significant improvement in the discriminatory accuracy, along with good calibration and greater net clinical benefit, of EFS (C-Index: 0.88; 95% CI: 0.829–0.933).

Conclusion: The radiomics signature can be used as a prognostic indicator for EFS in patients with hepatoblastoma. A combination of the radiomics signature and clinicopathologic risk factors showed better performance in terms of EFS prediction in patients with hepatoblastoma, which enabled precise clinical decision-making.

A new risk-stratification system for hepatoblastoma in children under six years old and the significance for prognosis evaluation-a 14-year retrospective study from a single center

BACKGROUND

This study explores and analyzes the clinical characteristics and prognostic factors of hepatoblastoma (HB) in children under 6 years old and establishes a new risk-stratification system for individualized therapy.

METHODS

The clinical data of 382 pediatric patients under 6 years old (231 males and 151 females) who had been diagnosed with HB by pathology between May 2005 and May 2019 were collected. By analyzing the risk factors influencing the survival rate of patients with HB, a new risk-stratification system was established, and it was compared with previous risk-stratification systems by a receiver operating characteristic (ROC) curve.

RESULTS

(1) According to a Kaplan-Meier survival analysis, the one-year, three-year, and five-year overall survival (OS) was 93.7, 84.0, and 73.9%, respectively, and the event-free survival (EFS) was 90.5, 79.2, and 67.5%, respectively. (2) The independent risk factors influencing prognosis in pediatric patients with HB were alpha-fetoprotein (AFP) < 100 ng/ml or > 1000 ng/ml (HR = 3.341, P = 0.005); platelet count > 400 × 10⁹/L (pooled hazard ratio [HR] = 2.123, P = 0.026); PRETEXT stage IV (HR = 4.026, P = 0.001); vascular involvement (HR = 2.178, P = 0.019); distant metastasis (HR = 2.634, P = 0.010);and multifocality (HR = 2.215, P = 0.012). (3) A new risk-stratification system was established and divided into three groups: low risk, moderate risk, and high risk. There were statistical differences among the three groups (P = 0.002). Compared with the previous risk-staging systems, there was no significant difference in the survival rate. Although the effect in the guiding therapy was the same, the area under the curve for the ROC curve was 0.835 (95% CI: 0.784-0.885) for the new stratification system.

CONCLUSION

This new risk-stratification system had a better predictive value for the prognosis of pediatric patients with HB than other stratification systems.

Clinical characteristics and prognostic factors of hepatoblastoma in 316 children aged under 3 years - a 14-year retrospective single-center study

Background

The aim of the present study was to summarize the clinical characteristics of in children aged under 3 years and analyze the related factors affecting the prognosis.

Methods

The clinical data of 316 children aged under 3 years (192 males and 124 females) who were admitted to Beijing Tongren Hospital with a pathological diagnosis of HB between May 2005 and May 2019 were analyzed retrospectively. The factors influencing the therapeutic effects on and survival of HB in children with HB were analyzed.

Results

(1) The median age of the enrolled patients was 1.45 years. The most common initial symptom was an abdominal mass (69.0%). The average serum alpha-fetoprotein (AFP) level and platelet count at the initial visit were (97,406.5 ± 5022.8) ng/mL and (418 ± 206) × 10⁹/L, respectively. The epithelial type was the main pathological type (51.9%). According to the PRETEXT preoperative typing system, the most common stage was stage III (57.0%), whereas according to the postoperative Evans staging system, the most common stage was stage IV (41.8%). At the initial visit, 62 cases (19.6%) had vascular invasion, 52 cases (16.5%) had extrahepatic tumor extension, and 20 cases (6.3%) had tumor rupture. Distant metastasis occurred in 132 cases, and the most common metastatic site was the lung (80.3%). The incidence in East China was relatively high (35.4%). (2) The children were followed up until May 2020 (the median follow-up duration was 62 months). It was found that 194 patients had complete remission and 62 had partial remission. The Kaplan–Meier survival analysis showed that the overall survival was 95.3, 88.2, and 79.8% at 1 year, 3 years, and 5 years, respectively, and the event-free survival was 91.1, 83.2, and 75.1%, respectively. The Cox regression analysis showed that AFP level, platelet count, PRETEXT IV, vascular invasion, and distant metastasis at the initial visit were independent risk factors for the prognosis of children with HB (p < 0.05 in all).

Conclusion

The prognosis of HB was correlated with the AFP level, platelet count, PRETEXT staging, vascular invasion, and distant metastasis at initial diagnosis.

Clinical Characteristics and Prognosis Analysis of Infantile Hepatoblastoma-A 15-Year Retrospective Single-Center Study

Objective

The present study aimed to summarize the clinical data of hepatoblastoma (HB) in infants under one year of age and to analyze the factors that affected the prognoses.

Methods

The clinical data of 132 pediatric patients with a pathologically confirmed HB, aged less than one year and who had visited the Pediatric Single Center of Beijing Tongren Hospital from May 2005 to May 2019, were retrospectively analyzed to summarize the clinical outcomes and prognoses.

Results

The male/female ratio was 1.27 and the median age was 8.40 months. The onset of HB was usually characterized by abdominal bulging (75.0%). The median level of AFP at the first visit was 154.7µg/mL, and the average platelet count was (405±166)×10⁹/L. The epithelial type (57.6%) was the predominant pathological type, and stage III (54.5%) was the main PRETEXT staging. Distant metastases occurred in 45 cases, with pulmonary metastases (86.7%) being the most common site. At the time of visit, 24 cases (18.2%) had either portal vein, hepatic vein, or vena cava infiltration. Five cases (3.8%) had a hemorrhage of the ruptured tumor, and 26 cases (19.7%) had multiple intrahepatic foci. At the follow-up in May 2020, the overall survival (OS) rate at one, three, and five years of age was 94.3%, 88.8%, and 80.1%, respectively, and the event-free survival rate was 91.8%, 86.9%, and 77.5%, respectively, by the Kaplan–Meier survival analysis. According to the Log rank test, pediatric patients with an AFP <100ng/mL, a PRETEXT stage IV, presence of distant metastases and multiple foci of the primary tumor at the initial diagnosis had poorer prognoses (P<0.05).

Conclusion

The prognosis of HB in infancy is relatively good, but is still vulnerable to multiple factors, such as tumor features leading to different AFP levels, PRETEXT stage, presence of distant metastases, and multiple intrahepatic foci.

Liver Tumors in Pediatric Patients

The most recent advance in the care of children diagnosed with hepatoblastoma and hepatocellular carcinoma is the Pediatric Hepatic International Tumor Trial, which opened to international enrollment in 2018. It is being conducted as a collaborative effort by the pediatric multicenter trial groups in North America, Europe, and the Far East. This international effort was catalyzed by a new unified global risk stratification system for hepatoblastoma, an international histopathologic consensus classification for pediatric liver tumors, and a revised 2017 collaborative update of the PRE-Treatment EXTent of disease radiographic based staging system.

High expression of IGF2-derived intronic miR-483 predicts outcome in hepatoblastoma

BACKGROUND

The role of microRNAs (miRs) as biomarkers to predict outcome in hepatoblastoma (HB), the most common malignant liver tumor in childhood, has still to be determined. Recently, the so-called four-miR signature has been described to efficiently stratify HB patients according to their prognosis.

OBJECTIVE

We examined the recently described four-miR signature for its clinical relevance in an independent validation cohort of HB patients and tried to optimize its predictive value by analyzing four additional miRs involved in HB biology.

METHODS

Expression of eight miR was determined in 29 tumor and 10 normal liver samples by TaqMan assays and association studies and Kaplan-Meier estimators determined their clinical relevance.

RESULTS

Stratifying HB patients by the four-miR signature showed no difference in patients' outcome, which was also reflected by the lack of association with any clinical risk parameter. Adding miR-23b-5p and miR-23b-3p did also not increase its discriminating power. However, the integration of miR-483-5p and miR-483-3p into the four-miR signature could predict patients with poor outcome that were associated with large tumors and vessel invasive growth with high accuracy.

CONCLUSIONS

The expansion of the four-miR signature by miR-483 serves as a useful biomarker to predict outcome of HB patients.

Molecular Mechanisms of Hepatoblastoma

Hepatoblastoma (HB) is the predominant primary liver tumor in children. While the prognosis is favorable when the tumor can be resected, the outcome is dismal for patients with progressed HB. Therefore, a better understanding of the molecular mechanisms responsible for HB is imperative for early detection and effective treatment. Sequencing analysis of human HB specimens unraveled the pivotal role of Wnt/β-catenin pathway activation in this disease. Nonetheless, β-catenin activation alone does not suffice to induce HB, implying the need for additional alterations. Perturbations of several pathways, including Hippo, Hedgehog, NRF2/KEAP1, HGF/c-Met, NK-1R/SP, and PI3K/AKT/mTOR cascades and aberrant activation of c-MYC, n-MYC, and EZH2 proto-oncogenes, have been identified in HB, although their role requires additional investigation. Here, we summarize the current knowledge on HB molecular pathogenesis, the relevance of the preclinical findings for the human disease, and the innovative therapeutic strategies that could be beneficial for the treatment of HB patients.

CHIC Risk Stratification System for Predicting the Survival of Children With Hepatoblastoma: Data From Children With Hepatoblastoma in China

Objective

The aim of this study was to compare the accuracy of the Children’s Oncology Group (COG) risk stratification system to the Children’s Hepatic tumor International Collaboration (CHIC) risk stratification system for predicting the prognosis of Chinese children with hepatoblastoma (HB).

Methods

Clinicopathological data of 86 patients diagnosed with HB between January 2014 and December 2017 were retrieved. The study endpoints were the 1- and 3-year overall survival (OS) and disease-free survival (DFS) were analyzed to evaluate the predictive value.

Results

The 1-, 3-year OS and DFS of the 86 patients were 86.0%, 76.3%, and 74.4%, 54.0%, respectively. Univariate analyses revealed that age at diagnosis had a significant role in prognosis for both OS and DFS, along with PRETEXT staging and metastasis at diagnosis. Multivariate analysis showed that metastasis at diagnosis (HR 3.628, 95% CI 1.404-9.378, P=0.008), PRETEXT staging system (HR 2.176, 95% CI 1.230-3.849, P=0.008) and age at diagnosis (HR 2.268, 95% CI 1.033-4.982, P=0.041) were independent factors for OS. For DFS, the independent factors were the PRETEXT staging system (HR 2.241, 95% CI 1.533-3.277, P<0.001) and age at diagnosis (HR 1.792, 95% CI 1.018-3.154, P=0.043). Both COG and CHIC risk stratification systems could effectively predict the prognosis of children with HB for OS. For DFS, the CHIC risk stratification system was more effective. In addition, the CHIC risk stratification system had a higher c-index (OS 0.743, DFS 0.730), compared to the COG risk stratification system (OS 0.726, DFS 0.594).

Conclusion

Age at diagnosis played a significant role in prognosis. Compared to the COG risk stratification system, the CHIC risk stratification system was superior in predicting the survival of Chinese children with HB.

Pilot study of the combination of sorafenib and fractionated irinotecan in pediatric relapse/refractory hepatic cancer (FINEX pilot study)

BACKGROUND

Preclinical observations suggested a synergistic effect of sorafenib (SFN) and irinotecan (CPT-11) in hepatoblastoma (HB). Thus, we conducted a feasibility study of fractionated CPT-11 combined with SFN to develop a new therapy against relapsed/refractory pediatric hepatic cancer (HC).

PROCEDURE

The study was originally designed as a phase I, standard 3+3 dose-finding study to evaluate dose-limiting toxicities (DLTs) for the regimen and the optimal CPT-11 dose in combination with SFN against relapsed/refractory pediatric HC, including HB and hepatocellular carcinoma (HCC). The enrolled patients received SFN at 200 mg/m² every 12 hours or 400 mg/m² every 24 hours daily combined with CPT-11 at 20 mg/m² /day on days 1 to 5 as an initial level 1 dose.

RESULTS

Six patients with HB (n = 4) or HCC (n = 2) were enrolled and treated with CPT-11 dose level 1. The median age at enrollment was 8.7 (6.2-16.3) years. All patients received platinum-containing chemotherapy, and five or two patients received CPT-11 or SFN before enrollment, respectively. Regimen toxicities were evaluable in all patients. One of six patients experienced a grade 4 transaminase levels increase, which was defined as a DLT per protocol. Grade 3/4 neutropenia and a grade 3 transaminase level increase occurred in three patients and one patient, respectively. All patients reported grade 1/2 toxicities such as anemia, skin toxicity, gastrointestinal symptoms, and hypoalbuminemia.

CONCLUSIONS

Although the study was terminated before determining the maximum-tolerated CPT-11 dose, SFN and CPT-11 at the level 1 dose were concluded to be tolerable in pediatric patients with HC.

A combined clinical and biological risk classification improves prediction of outcome in hepatoblastoma patients

AIM

Stratification of hepatoblastoma (HB) patients is based on clinical and imaging characteristics obtained at the time of diagnosis. We aim to integrate biomarkers into a tool that accurately predicts survival of HB patients.

METHODS

We retrospectively analysed 174 HB patients for the presence of four biomarkers and explored their prognostic potential by correlating with overall survival (OS) and event-free survival (EFS).

RESULTS

Mutations of CTNNB1, NFE2L2 and TERT were found in 135 (78%), 10 (6%) and 10 (6%) patients, respectively, and the adverse C2 subtype of the 16-gene signature in 63 (36%) patients. C2-patients had more frequent metastatic disease, higher alpha-fetoprotein levels, non-fetal histology and significantly worse 3-year OS (68% versus 95%) and EFS (63% versus 87%) than C1-patients. Patients carrying a NFE2L2 mutation had a significantly worse 3-year OS (57% versus 88%) than NFE2L2 wild-type patients and were more likely to have vessel invasive growth and non-fetal histology. TERT mutations were almost exclusively found in older patients, whereas CTNNB1 mutations showed no association with any clinical feature or outcome. In a multivariable analysis, the C2 subtype remained a significant predictor of poor outcome with hazard ratios of 6.202 and 3.611 for OS and EFS, respectively. When added to the Children's Hepatic tumors International Collaboration risk stratification, the presence of the C2 subtype identified a group of high-risk patients with a very poor outcome.

CONCLUSION

We propose a new stratification system based on the combination of clinical factors and the 16-gene signature, which may facilitate a risk-adapted management of HB patients.

Cost-effectiveness Analysis of Screening Extremely Low Birth Weight Children for Hepatoblastoma Using Serum Alpha-fetoprotein

OBJECTIVES

To evaluate the cost-effectiveness of screening children born at extremely low birth weight (ELBW) for hepatoblastoma using serial serum alpha-fetoprotein measurements.

STUDY DESIGN

We created a decision tree to evaluate the cost effectiveness of screening children born at ELBW between 3 and 48 months of age compared with current standard of care (no screening). Our model used discounted lifetime costs and monetary benefits in 2018 US dollars, based on estimates in the published literature. The effects of uncertainty in model parameters were also assessed using univariate sensitivity analyses, in which we changed the values for one parameter at a time to assess the effect on the estimated incremental cost-effectiveness ratio.

RESULTS

For the estimated 55 699 children born at ELBW in the US each year, this screening is associated with 77.7 additional quality-adjusted life-years (QALYs) at a cost of $8.7 million. This results in an incremental cost-effectiveness ratio of about $112 000/QALY, which is considered cost effective from a US societal perspective. For children diagnosed with hepatoblastoma, our model finds that the screening regimen is associated with a 10.1% increase in survival, a 4.18% increase in expected QALYs, and a $245 184 decrease in expected cost.

CONCLUSIONS

Screening ELBW children for hepatoblastoma between 3 and 48 months of age dominates the alternative and is cost effective from a societal perspective.

Tumor rupture in hepatoblastoma: A high risk factor?

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.

The importance of age as prognostic factor for the outcome of patients with hepatoblastoma: Analysis from the Children's Hepatic tumors International Collaboration (CHIC) database

PURPOSE

Treatment outcomes for hepatoblastoma have improved markedly in the contemporary treatment era, principally due to therapy intensification, with overall survival increasing from 35% in the 1970s to 90% at present. Unfortunately, these advancements are accompanied by an increased incidence of toxicities. A detailed analysis of age as a prognostic factor may support individualized risk-based therapy stratification.

METHODS

We evaluated 1605 patients with hepatoblastoma included in the CHIC database to assess the relationship between event-free survival (EFS) and age at diagnosis. Further analysis included the age distribution of additional risk factors and the interaction of age with other known prognostic factors.

RESULTS

Risk for an event increases progressively with increasing age at diagnosis. This pattern could not be attributed to the differential distribution of other known risk factors across age. Newborns and infants are not at increased risk of treatment failure. The interaction between age and other adverse risk factors demonstrates an attenuation of prognostic relevance with increasing age in the following categories: metastatic disease, AFP < 100 ng/mL, and tumor rupture.

CONCLUSION

Risk for an event increased with advancing age at diagnosis. Increased age attenuates the prognostic influence of metastatic disease, low AFP, and tumor rupture. Age could be used to modify recommended chemotherapy intensity.

Outcomes of children with hepatoblastoma who underwent liver resection at a tertiary hospital in China: a retrospective analysis

BACKGROUND

To report the outcomes of hepatoblastoma resected in our institution.

METHODS

We diagnosed 135 children with hepatoblastoma at our institution between January 2010 and December 2017. Patients who underwent liver resection were included for analysis. However, patients who abandoned treatment after diagnosis were excluded from analysis, but their clinical characteristics were provided in the supplementary material.

RESULTS

Forty-two patients abandoned treatment, whereas 93 patients underwent liver resection and were included for statistical analysis. Thirty-six, 23, 3, and 31 patients had PRETEXT stages II, III, IV, and unspecified tumours, respectively. Seven patients had ruptured tumour; 9 had lung metastasis (one patient had portal vein thrombosis concurrently). Sixteen patients underwent primary liver resection; 22, 25, and 30 patients received cisplatin-based neoadjuvant chemotherapy and delayed surgery, preoperative transarterial chemoembolization (TACE) and delayed surgery, and a combination of cisplatin-based neoadjuvant chemotherapy, TACE, and delayed surgery, respectively. Forty patients had both PRETEXT and POST-TEXT information available for analysis. Twelve patients were down-staged after preoperative treatment, including 2, 8, and 2 patients from stages IV to III, III to II, and II to I, respectively. Ten patients with unspecified PRETEXT stage were confirmed to have POST-TEXT stages II (n = 8) and I (n = 2) tumours. Seven tumours were associated with positive surgical margins, and 12 patients had microvascular involvement. During a median follow-up period of 30.5 months, 84 patients survived without relapse, 9 experienced tumour recurrence, and 4 died. The 2-year event-free survival (EFS) and overall survival (OS) rates were 89.4 ± 3.4%, and 95.2 ± 2.4%, respectively; they were significantly better among patients without metastasis (no metastasis vs metastasis: EFS, 93.5 ± 3.7% vs 46.7 ± 19.0%, adjusted p = 0.002. OS, 97.6 ± 2.4% vs 61.0 ± 18.1%, adjusted p = 0.005), and similar among patients treated with different preoperative strategies (chemotherapy only vs TACE only vs Both: EFS, 94.7 ± 5.1% vs 91.7 ± 5.6% vs 85.6 ± 6.7%, p = 0.542. OS, 94.1 ± 5.7% vs 95.7 ± 4.3% vs 96.7 ± 3.3%, p = 0.845).

CONCLUSION

The OS for patients with hepatoblastoma who underwent liver resection was satisfactory. Neoadjuvant chemotherapy and TACE seemed to have a similar effect on OS. However, the abandonment of treatment by patients with hepatoblastoma was common, and may have biased our results.

TUG1 Promoted Tumor Progression by Sponging miR-335-5p and Regulating CXCR4-Mediated Infiltration of Pro-Tumor Immunocytes in CTNNB1-Mutated Hepatoblastoma

Introduction

HB presents with the highest frequency of CTNNB1 mutations, resulting in activation of Wnt signaling pathway. A number of studies have demonstrated CTNNB1 mutation contributed to the development of HB. However, limited research explored the function of lncRNAs in HB with CTNNB1 mutation.

Methods

We screened lncRNA expression profiles in CTNNB1-mutated HB samples and identified lncRNAs associated with malignant phenotype in HB. The association between lncRNA and immune microenvironment was investigated. The biological function of lncRNA was further explored using in vitro experiments.

Results

TUG1 was identified as onco-lncRNA in CTNNB1-mutated HB. TUG1 was shown to be associated with the infiltration of pro-tumor immunocytes via regulating the expression of CXCR4, a chemokine receptor playing a critical role in regulation of immune microenvironment. Inhibiting TUG1 could increase endogenous levels of miR-335-5p and consequently downregulating CXCR4, a direct target of miR-335-5p.

Conclusion

Our findings provide evidence for TUG1 mediating infiltration of pro-tumor immunocytes in HB patients carrying CTNNB1 mutation. TUG1-miR-335-5p-CXCR4 axis might be a promising immunological target for the treatment of HB patients.

Liver Transplantation for Pediatric Liver Cancer

Unresectable hepatocellular carcinoma (HCC) was first removed successfully with total hepatectomy and liver transplantation (LT) in a child over five decades ago. Since then, children with unresectable liver cancer have benefitted greatly from LT and a confluence of several equally important endeavors. Regional and trans-continental collaborations have accelerated the development and standardization of chemotherapy regimens, which provide disease control to enable LT, and also serve as a test of unresectability. In the process, tumor histology, imaging protocols, and tumor staging have also matured to better assess response and LT candidacy. Significant trends include a steady increase in the incidence of and use of LT for hepatoblastoma, and a significant improvement in survival after LT for HCC with each decade. Although LT is curative for most unresectable primary liver sarcomas, such as embryonal sarcoma, the malignant rhabdoid tumor appears relapse-prone despite chemotherapy and LT. Pediatric liver tumors remain rare, and diagnostic uncertainty in some settings can potentially delay treatment or lead to the selection of less effective chemotherapy. We review the current knowledge relevant to diagnosis, LT candidacy, and post-transplant outcomes for these tumors, emphasizing recent observations made from large registries or larger series.

MicroRNA dysregulation interplay with childhood abdominal tumors

Abdominal tumors (AT) in children account for approximately 17% of all pediatric solid tumor cases, and frequently exhibit embryonal histological features that differentiate them from adult cancers. Current molecular approaches have greatly improved the understanding of the distinctive pathology of each tumor type and enabled the characterization of novel tumor biomarkers. As seen in abdominal adult tumors, microRNAs (miRNAs) have been increasingly implicated in either the initiation or progression of childhood cancer. Moreover, besides predicting patient prognosis, they represent valuable diagnostic tools that may also assist the surveillance of tumor behavior and treatment response, as well as the identification of the primary metastatic sites. Thus, the present study was undertaken to compile up-to-date information regarding the role of dysregulated miRNAs in the most common histological variants of AT, including neuroblastoma, nephroblastoma, hepatoblastoma, hepatocarcinoma, and adrenal tumors. Additionally, the clinical implications of dysregulated miRNAs as potential diagnostic tools or indicators of prognosis were evaluated.

Hepatoblastoma relapses with a normal level of alpha-fetoprotein: report of two cases

Hepatoblastoma (HB) is the most common malignant liver tumor in children. The level of alpha-fetoprotein (AFP) is used for monitoring the response to antitumor therapy and for diagnosing relapses. The occurrence of HB relapses with normal AFP levels in patients who had elevated levels of this tumor marker at disease onset is considered to be an uncommon situation. The aim of this study was to describe cases in which AFP-negative hepatoblastoma relapses developed. The study participants included two HB patients who were initially stratified into high-risk and standard-risk groups and who received treatment at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology and the Petrovsky National Research Center of Surgery inMoscow. At the moment of relapse acknowledgement these patients had normal AFP levels, which was confirmed by serial measurements. Immunohistochemistry (IHC) tests were performed on paired samples of the tumor at disease onset and at disease relapse respectively to evaluate AFP expression. The presented clinical cases demonstrate that normal AFP levels, when accompanied by suspicious clinical symptoms, do not allow to exclude an HB relapse. The possibility of relapse with a normal AFP level reinforces the importance of following the current plan of screening tests, which includes not only an evaluation of AFP levels, but also other tests such as a chest X-ray and an abdominal ultrasound. Parents gave their consent to use information about the child in the article.

Surgical management of locally-advanced and metastatic hepatoblastoma

Advanced stage hepatoblastoma, including both locally advanced primary tumors as well as metastatic disease, poses unique clinical challenges. Despite substantial advances in chemotherapeutics, surgical extirpation remains the mainstay of cure for this tumor. Locally advanced tumors that involve multiple hepatic lobes and/or invade significant vascular structures can be managed either by complex hepatic resections or liver transplantation. We review the indications, roles, and outcomes of these surgical approaches as well as those for the resection of pulmonary metastases.

Prognostic Factors for Event-Free Survival in Pediatric Patients with Hepatoblastoma Based on the 2017 PRETEXT and CHIC-HS Systems

This study aimed to evaluate the prognostic value of variables used in the 2017 PRE-Treatment EXTent of tumor (PRETEXT) system and the Children's Hepatic tumors International Collaboration-Hepatoblastoma Stratification (CHIC-HS) system in pediatric patients with hepatoblastoma. A retrospective analysis of data from the pediatric hepatoblastoma registry of a tertiary referral center was conducted to evaluate the clinical and imaging variables (annotation factors) of the PRETEXT staging system. The primary outcome was event-free survival (EFS). Data from 84 patients (mean age: 2.9 ± 3.5 years) identified between 1998 and 2017 were included. Univariable Cox proportional hazards analysis revealed that PRETEXT annotation factors P (portal vein involvement), F (multifocality of tumor), and M (distant metastasis) showed a significant negative association with EFS. Multivariable Cox proportional hazard analysis showed that factor F was the strongest predictor (HR (hazard ratio), 2.908; 95% CI (confidence interval), 1.061-7.972; p = 0.038), whereas factor M showed borderline significance (HR, 2.416; 95% CI, 0.918-6.354; p = 0.074). The prediction model based on F and M (F + M) showed good performance to predict EFS (C-statistic, 0.734; 95% CI, 0.612-0.854). In conclusion, the PRETEXT annotation factor F was the strongest predictor of EFS, and the F + M model showed good performance to predict EFS in pediatric patients with hepatoblastoma.