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

Management of undifferentiated embryonal sarcoma of the liver: A Pediatric Surgical Oncology Research Collaborative study

BACKGROUND

Undifferentiated embryonal sarcoma of the liver (UESL) is a rare tumor for which there are few evidence-based guidelines. The aim of this study was to define current management strategies and outcomes for these patients using a multi-institutional dataset curated by the Pediatric Surgical Oncology Research Collaborative.

METHODS

Data were collected retrospectively for patients with UESL treated across 17 children's hospitals in North America from 1989 to 2019. Factors analyzed included patient and tumor characteristics, PRETEXT group, operative details, and neoadjuvant/adjuvant regimens. Event-free and overall survival (EFS, OS) were the primary and secondary outcomes, respectively.

RESULTS

Seventy-eight patients were identified with a median age of 9.9 years [interquartile range [IQR): 7-12]. Twenty-seven patients underwent resection at diagnosis, and 47 patients underwent delayed resection, including eight liver transplants. Neoadjuvant chemotherapy led to a median change in maximum tumor diameter of 1.6 cm [IQR: 0.0-4.4] and greater than 90% tumor necrosis in 79% of the patients undergoing delayed resection. R0 resections were accomplished in 63 patients (81%). Univariate analysis found that metastatic disease impacted OS, and completeness of resection impacted both EFS and OS, while multivariate analysis revealed that R0 resection was associated with decreased expected hazards of experiencing an event [hazard ratio (HR): 0.14, 95% confidence interval (CI): 0.04-0.6]. At a median follow-up of 4 years [IQR: 2-8], the EFS was 70.0% [95% CI: 60%-82%] and OS was 83% [95% CI: 75%-93%].

CONCLUSION

Complete resection is associated with improved survival for patients with UESL. Neoadjuvant chemotherapy causes minimal radiographic response, but significant tumor necrosis.

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.

The effect of donor graft type on survival after liver transplantation for hepatoblastoma in children

BACKGROUND

Liver transplantation (LT) is the only potentially curative option for children with unresectable hepatoblastoma (HBL). Although post-transplant outcomes have improved in the contemporary era, the impact of donor graft type on survival remains unclear.

METHODS

Using the United Network for Organ Sharing database (02/2002-06/2021), demographics, clinical characteristics, and patient and graft survival were analyzed in children (<18 years) who underwent LT for HBL according to donor graft type. The Kaplan-Meier method, log-rank tests, and Cox regression modeling were used to evaluate the effect of whole, partial, and split deceased donor liver transplantation (DDLT) and living donor liver transplantation (LDLT) on patient and graft survival.

RESULTS

A total of 590 pediatric HBL LT recipients (344 whole graft DDLT; 62 partial graft DDLT; 139 split graft DDLT; 45 LDLT) were included. During 2012-2021 the proportion of LDLTs for HBL decreased to about 5% compared with about 11% during 2002-2011. No significant differences were identified by donor graft type in either patient survival (log-rank test, p = .45) or graft survival (log-rank test, p = .69). The results remained similar during the 2002-2011 era, while during the 2012-2021 era, split graft DDLT was associated with decreased graft loss risk versus whole graft DDLT (hazard ratio: 0.48, 95% confidence interval: 0.23-0.99, p = .046) without any other significant between-group differences.

CONCLUSIONS

Utilizing non-whole liver grafts can increase access to LT in children with unresectable HBL while ensuring favorable outcomes. LDLT is underutilized in children with HBL in the United States, and efforts to explore LDLT options should be undertaken.

Parenchyma Sparing Anatomic Liver Resections (Bi- and Uni-Segmentectomies) for Liver Tumours in Children-A Single-Centre Experience

Purpose: To present a single-centre experience in bi- and uni-segmentectomies for primary liver tumours in children.

METHODS

This study included 23 patients that underwent (bi)segmentectomy. There were 15 malignant tumours (hepatoblastoma-13 patients), 7 benign tumours, and 1 calcifying nested stromal epithelial tumour.

RESULTS

The median tumour diameter was 52 mm (range 15-170 mm). Bisegmentectomy 2-3 was most frequently performed (seven patients), followed by bisegmentectomy 5-6 (four patients). The median operative time was 225 min (range 95-643 min). Intraoperative complications occurred in two patients-small bowel perforation in one and an injury of the small peripheral bile duct resulting in biloma in the other. The median resection margin in patients with hepatoblastoma was 3 mm (range 1-15 mm). Microscopically negative margin status was achieved in 12 out of 13 patients. There were two recurrences. After a median follow-up time of 38 months (range 12-144 months), all 13 patients with HB were alive with no evidence of disease. Two relapsed patients were alive with no evidence of disease.

CONCLUSIONS

From the available literature and data presented here, we propose that (bi)segmentectomy can become a viable surgical option in carefully selected paediatric patients and is sufficient to achieve a cure. Further studies evaluating the impact of parenchymal preservation surgery on surgical and oncological outcome should be conducted with a larger dataset.

Mesenchymal hamartoma versus hepatoblastoma: A diagnostic dilemma

INTRODUCTION AND IMPORTANCE

Pediatric hepatic tumors present diagnostic challenges due to diverse clinical presentations and limited patient communication. Elevated serum alpha-fetoprotein (AFP) levels, often associated with hepatoblastoma, can occur in various hepatic conditions, adding complexity to diagnosis. This report emphasizes the importance of comprehensive assessment and integrated interpretation in such cases.

CASE PRESENTATION

We present a rare case of a 1-year-old female child with abdominal swelling and hepatomegaly. Imaging revealed a hypodense hepatic lesion with punctate calcifications. Initial biopsy suggested mesenchymal hamartoma, but subsequent biopsy confirmed hepatoblastoma, highlighting the diagnostic complexity.

CLINICAL DISCUSSION

Hepatoblastoma is the most common pediatric liver tumor, typically presenting with nonspecific symptoms. Serum AFP levels are elevated, aiding diagnosis. Imaging reveals heterogeneous, hypervascular masses. Treatment includes surgery and chemotherapy. Mesenchymal hamartoma is a rare benign tumor with variable symptoms and imaging features, emphasizing the need for histopathological confirmation. This case underscores the importance of a comprehensive diagnostic approach.

CONCLUSION

Diagnosing pediatric hepatic tumors requires an integrated assessment of clinical, laboratory, and imaging findings. Confirmatory biopsies are essential, as demonstrated by this case, where an initial diagnosis of mesenchymal hamartoma was revised to hepatoblastoma. Collaborative, multidisciplinary approaches are crucial for accurate diagnosis and effective therapeutic planning, offering hope for improved outcomes in these complex cases.

Prognostic value of systemic inflammation response index in hepatoblastoma patients receiving preoperative neoadjuvant chemotherapy

Introduction

Inflammation is closely associated with tumor development and patient prognosis. The objective of this study is to assess the prognostic value of the preoperative inflammatory indexes in pediatric hepatoblastoma patients who receive neoadjuvant chemotherapy.

Methods

A retrospective analysis was performed on clinical and pathological data of 199 hepatoblastoma patients who underwent hepatectomy with preoperative neoadjuvant chemotherapy from January 2015 to June 2020. The receiver operating characteristic curve was used to evaluate the prognostic value of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI) in predicting OS and EFS. Patients were grouped based on optimal cutoff values of preoperative inflammatory indexes. Survival rates were calculated using the Kaplan-Meier method, and survival outcomes were compared between groups using the log-rank test. Univariate and multivariate Cox proportional hazards regression models were used to identify independent prognostic factors, and a nomogram was constructed using R software to predict the probability of OS.

Results

The receiver operating characteristic curve showed prognostic value for OS, not EFS, in preoperative inflammatory indexes. Patients were categorized into low/high groups: SII ≤ 266.70/higher, NLR ≤ 1.24/higher, PLR ≤ 85.25/higher, and SIRI ≤ 0.72/higher. High NLR, PLR, SII, and SIRI groups had significantly lower 5-year OS than their low counterparts (all p-value < 0.05). The Cox analysis identified four independent prognostic factors: SIRI (HR=2.997, 95% CI: 1.119-8.031), microvascular invasion (HR=2.556, 95% CI: 1.14-5.73), the post-treatment extent of disease (POSTTEXT) staging (IV vs. I: HR=244.204, 95% CI:11.306-5274.556), and alpha-fetoprotein (>100 ng/ml: HR=0.11, 95% CI: 0.032-0.381) for hepatoblastoma patients with neoadjuvant chemotherapy. High SIRI group had more patients with adverse NLR, SII, and POSTTEXT III (all p-value < 0.05). Independent prognostic factors led to an OS nomogram with a concordance index of 0.85 (95% CI: 0.78-0.91, p-value = 1.43e-27) and the calibration curve showed a good fit between the prediction curve and the true curve.

Conclusions

SIRI is an independent prognostic factor of hepatoblastoma patients receiving neoadjuvant chemotherapy. The OS nomogram based on SIRI, POSTTEXT staging, MiVI, and AFP can be used to assess the prognosis of those patients.

Critical elements of pediatric liver cancer surgery

The appropriate management of pediatric liver malignancies, primarily hepatoblastoma and hepatocellular carcinoma, requires an in depth understanding of contemporary preoperative risk stratification, experience with advanced hepatobiliary surgery, and a good relationship with one's local or regional liver transplant center. While chemotherapy regimens have become more effective, operative indications more well-defined, and overall survival improved, the complexity of liver surgery in small children provides ample opportunity for protocol violation, inadequate resection, and iatrogenic morbidity. These guidelines represent the distillation of contemporary literature and expert opinion as a means to provide a framework for preoperative planning and intraoperative decision-making for the pediatric surgeon.

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.

Quality of Life Outcomes for Patients Who Underwent Conventional Resection and Liver Transplantation for Locally Advanced Hepatoblastoma

Hepatoblastoma is the most common malignant liver tumor of childhood, with liver transplant and extended resection used as surgical treatments for locally advanced tumors. Although each approach has well-described post-operative complications, quality-of-life outcomes have not been described following the two interventions. Long-term pediatric survivors of hepatoblastoma who underwent conventional liver resection or liver transplantation at a single institution from January 2000-December 2013 were recruited to complete quality-of-life surveys. Survey responses for the Pediatric Quality of Life Generic Core 4.0 (PedsQL, n = 30 patient and n = 31 parent surveys) and Pediatric Quality of Life Cancer Module 3.0 (PedsQL-Cancer, n = 29 patient and n = 31 parent surveys) were collected from patients and parents. The mean total patient-reported PedsQL score was 73.7, and the parent-reported score was 73.9. There were no significant differences in scores on the PedsQL between patients who underwent resection compared to those who underwent transplantation (p > 0.05 for all comparisons). On the PedsQL-Cancer module, procedural anxiety scores were significantly lower for patients who underwent resection as compared to transplant (M = 33.47 points less, CI [-60.41, -6.53], p-value 0.017). This cross-sectional study demonstrates that quality of life outcomes are overall similar among patients receiving transplants and resections. Patients who received a resection reported worse procedural anxiety.

Ferumoxytol-Enhanced MRI in Children and Young Adults: State of the Art

Ferumoxytol is an ultrasmall iron oxide nanoparticle that was originally approved by the FDA in 2009 for IV treatment of iron deficiency in adults with chronic kidney disease. Subsequently, its off-label use as an MRI contrast agent increased in clinical practice, particularly in pediatric patients in North America. Unlike conventional MRI contrast agents that are based on the rare earth metal gadolinium (gadolinium-based contrast agents), ferumoxytol is biodegradable and carries no potential risk of nephrogenic systemic fibrosis. At FDA-approved doses, ferumoxytol shows no long-term tissue retention in patients with intact iron metabolism. Ferumoxytol provides unique MRI properties, including long-lasting vascular retention (facilitating high-quality vascular imaging) and retention in reticuloendothelial system tissues, thereby supporting a variety of applications beyond those possible with gadolinium-based contrast agents (GBCAs). This Clinical Perspective describes clinical and early translational applications of ferumoxytol-enhanced MRI in children and young adults through off-label use in a variety of settings, including vascular, cardiac, and cancer imaging, drawing on the institutional experience of the authors. In addition, we describe current advances in pre-clinical and clinical research using ferumoxytol in cellular and molecular imaging as well as the use of ferumoxytol as a novel potential cancer therapeutic agent.

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.

Surgical management in hepatoblastoma: points to take

Hepatoblastoma is the most common primary malignant paediatric liver tumour and surgery remains the cornerstone of its management. The aim of this article is to present the principles of surgical treatment of hepatoblastoma. All aspects of surgery in hepatoblastoma are discussed, from biopsy, through conventional and laparoscopic liver resections, to extreme resection with adjacent structures, staged hepatectomy and transplantation.

Role of Interventional Radiology in Pediatric Cancer Patients

PURPOSE OF REVIEW

Pediatric interventional radiology (IR) is a growing subspecialty. Here, we review the current role of IR in children with cancer, which uses imaging such as ultrasound, fluoroscopy, and computed tomography to perform minimally invasive procedures. These include biopsy, needle localization, central venous access, thermal ablation, transarterial chemoembolization, transarterial radioembolization with yttrium-90, non-tunneled/tunneled drainage catheter placement, and lymphatic interventions.

RECENT FINDINGS

Although locoregional therapies for the treatment of cancer in adults are common, they are less common in children, perhaps due to the relative rarity of cancer in children, their typically better performance status, and paucity of comorbidities. Preliminary results from small-scale studies for ablation, transarterial chemoembolization, and transarterial radioembolization with yttrium-90 used in the front-line armamentarium of curative therapy are encouraging. Pediatric IR offers an array of minimally invasive procedures intended to diagnose and treat pediatric cancer patients. However, more research is required to determine the efficacy of locoregional therapy in children and to define the clinical scenarios where benefit is likely to be optimized.

PIM3 kinase promotes tumor metastasis in hepatoblastoma by upregulating cell surface expression of chemokine receptor cxcr4

Patients presenting with metastatic hepatoblastoma have limited treatment options and survival rates as low as 25%. We previously demonstrated that Proviral Integration site in Maloney murine leukemia virus 3 (PIM3) kinase promotes tumorigenesis and cancer cell stemness in hepatoblastoma. In this study, we assessed the role of PIM3 kinase in promoting hepatoblastoma metastasis. We utilized a tail vein injection model of metastasis to evaluate the effect of CRISPR/Cas9-mediated PIM3 knockout, stable overexpression of PIM3, and pharmacologic PIM inhibition on the formation of lung metastasis. In vivo studies revealed PIM3 knockout impaired the formation of lung metastasis: 5 out of 6 mice injected with wild type hepatoblastoma cells developed lung metastasis while none of the 7 mice injected with PIM3 knockout hepatoblastoma cells developed lung metastasis. PIM3 overexpression in hepatoblastoma increased the pulmonary metastatic burden in mice and mechanistically, upregulated the phosphorylation and cell surface expression of CXCR4, a key receptor in the progression of cancer cell metastasis. CXCR4 blockade with AMD3100 decreased the metastatic phenotype of PIM3 overexpressing cells, indicating that CXCR4 contributed to PIM3's promotion of hepatoblastoma metastasis. Clinically, PIM3 expression correlated positively with CXCR4 expression in primary hepatoblastoma tissues. In conclusion, we have shown PIM3 kinase promotes the metastatic phenotype of hepatoblastoma cells through upregulation of CXCR4 cell surface expression and these findings suggest that targeting PIM3 kinase may provide a novel therapeutic strategy for metastatic hepatoblastoma.

Hepatoblastoma Cancer Stem Cells Express PD-L1, Reveal Plasticity and Can Emerge upon Chemotherapy

The biology of cancer stem cells (CSCs) of pediatric cancers, such as hepatoblastoma, is sparsely explored. This is mainly due to the very immature nature of these tumors, which complicates the distinction of CSCs from the other tumor cells. Previously, we identified a CSC population in hepatoblastoma cell lines expressing the CSC markers CD34 and CD90, cell surface Vimentin (csVimentin) and binding of OV-6. In this study, we detected the co-expression of the immune escape factor PD-L1 in the CSC population, whereas the other tumor cells remained negative. FACS data revealed that non-CSCs give rise to CSCs, reflecting plasticity of CSCs and non-CSCs in hepatoblastoma as seen in other tumors. When we treated cells with cisplatin and decitabine, a new CD34^+/lowOV-6^lowCD90⁺ population emerged that lacked csVimentin and PD-L1 expression. Expression analyses showed that this new CSC subset shared similar pluripotency and EMT features with the already-known CSCs. FACS results further revealed that this subset is also generated from non-CSCs. In conclusion, we showed that hepatoblastoma CSCs express PD-L1 and that the biology of hepatoblastoma CSCs is of a plastic nature. Chemotherapeutic treatment leads to another CSC subset, which is highly chemoresistant and could be responsible for a poor prognosis after postoperative chemotherapy.

An evaluation of the association between radiological parameters and survival outcomes in pediatric patients with hepatoblastoma

BACKGROUND

We evaluated the survival outcomes following hepatic resection as a treatment modality in pediatric patients with hepatoblastoma at a single institution, and to identify radiological parameters associated with poorer survival outcomes.

METHODS

This was a retrospective cohort study. Medical records were reviewed, pertaining to pediatric patients diagnosed with hepatoblastoma who underwent surgical resection at a university hospital in Thailand between 2004 and 2021. Radiological parameters, clinical factors, and pathological data were also collected. Survival analysis was performed, and prognostic factors were identified using logistic regression analysis.

RESULTS

Forty-two suitable patients were identified. Three cases with incomplete data were excluded, resulting in 39 cases being analyzed. Except for two, all patients received preoperative chemotherapy following the Thai Pediatric Oncology Group regimen. The two- and five-year overall survival rates were 78.0% and 70.9%, respectively. Upon analysis, the radiological parameters associated with poorer survival were poor response to neoadjuvant chemotherapy, presence of metastasis, post-chemotherapy tumor diameter, Post treatment extent of disease (POSTTEXT) Stage IV disease, presence of portal vein involvement, and presence of residual disease; poor neoadjuvant-response, portal vein involvement, and metastasis were independently associated with worse outcomes. In patients with non-metastatic hepatoblastoma who had at least a 25% reduction in size following neoadjuvant chemotherapy, the 5-year survival rate was 90.9% (95% CI 50.8-98.6%).

CONCLUSIONS

Although preoperative evaluation of the tumor extent staging did not significantly affect survival, portal vein involvement as per POSTTEXT staging, stable or increasing tumor size, and metastasis following neoadjuvant chemotherapy were associated with poor overall survival.

LEVEL OF EVIDENCE

IIB.

Analysis of risk factors for angiolymphatic invasion and establishment of a predictive nomogram for hepatoblastomas

BACKGROUND

Hepatoblastomas (HBs)are malignant liver tumors that most commonly develop in pediatric patients. Although lymph node metastasis is rare in HBs, angiolymphatic invasion (ALI) is a risk factor affecting the prognosis of HBs. This study aimed to evaluate the risk factors for angiolymphatic invasion in HBs.

METHODS

We retrospectively analyzed the clinical data of 165 patients with HBs who underwent surgical resection at our institution between March 2016 and May 2021 and established binary logistic regression models to predict risk factors for ALI. The R software was used to construct the nomogram.

RESULTS

For the regression model based on the Children's Hepatic Tumors International Collaboration-Hepatoblastoma Stratification (CHIC-HS) system, tumor diameter, tumor response to neoadjuvant chemotherapy (NACT), and CHIC-HS were identified as independent risk factors for angiolymphatic invasion. For the regression model based on the pretreatment extent of the tumor (PRETEXT) stages with annotation factors, tumor diameter, multifocality, macrovascular involvement, tumor response to NACT, and PRETEXT stages were identified as independent risk factors for angiolymphatic invasion.

CONCLUSIONS

Using the CHIC-HS system/PRETEXT stages with annotation factors, tumor diameter and tumor response to NACT were identified as independent risk factors for angiolymphatic invasion. The distance between the tumor and portal vein was negatively correlated with the occurrence of multifocal tumors.

LEVEL OF EVIDENCE

Level III.

Hepatoblastomas with carcinoma features represent a biological spectrum of aggressive neoplasms in children and young adults

BACKGROUND & AIMS

Hepatoblastoma (HB) and hepatocellular carcinoma (HCC) are the predominant liver cancers in children, though their respective treatment options and associated outcomes differ dramatically. Risk stratification using a combination of clinical, histological, and molecular parameters can improve treatment selection, but it is particularly challenging for tumors with mixed histological features, including those in the recently created hepatocellular neoplasm not otherwise specified (HCN NOS) provisional category. We aimed to perform the first molecular characterization of clinically annotated cases of HCN NOS.

METHODS

We tested whether these histological features are associated with genetic alterations, cancer gene dysregulation, and outcomes. Namely, we compared the molecular features of HCN NOS, including copy number alterations, mutations, and gene expression profiles, with those in other pediatric hepatocellular neoplasms, including HBs and HCCs, as well as HBs demonstrating focal atypia or pleomorphism (HB FPAs), and HBs diagnosed in older children (>8).

RESULTS

Molecular profiles of HCN NOS and HB FPAs revealed common underlying biological features that were previously observed in HCCs. Consequently, we designated these tumor types collectively as HBs with HCC features (HBCs). These tumors were associated with high mutation rates (∼3 somatic mutations/Mb) and were enriched with mutations and alterations in key cancer genes and pathways. In addition, recurrent large-scale chromosomal gains, including gains of chromosomal arms 2q (80%), 6p (70%), and 20p (70%), were observed. Overall, HBCs were associated with poor clinical outcomes.

CONCLUSIONS

Our study indicates that histological features seen in HBCs are associated with combined molecular features of HB and HCC, that HBCs are associated with poor outcomes irrespective of patient age, and that transplanted patients are more likely to have good outcomes than those treated with chemotherapy and surgery alone. These findings highlight the importance of molecular testing and early therapeutic intervention for aggressive childhood hepatocellular neoplasms.

LAY SUMMARY

We molecularly characterized a class of histologically aggressive childhood liver cancers and showed that these tumors are clinically aggressive and that their observed histological features are associated with underlying recurrent molecular features. We proposed a diagnostic algorithm to identify these cancers using a combination of histological and molecular features, and our analysis suggested that these cancers may benefit from specialized treatment strategies that may differ from treatment guidelines for other childhood liver cancers.

Advances in the treatment of pediatric solid tumors: A 50-year perspective

In the United States, more than 10 000 cancers occur annually in children aged 0-14 years, and more than 5000 in adolescents aged 15-19. In the last 50 years, significant advances have been made in imaging, molecular pathology, stage and risk assessment, surgical approach, multidisciplinary treatment, and survival for pediatric solid tumors (particularly neuroblastoma, Wilms tumor, rhabdomyosarcoma, and hepatoblastoma). Moreover, the molecular driver for fibrolamellar hepatocellular carcinoma, which occurs in adolescence and young adulthood, has been identified.

Teratoid Hepatoblastoma with Multi-Lineage Differentiation: An Uncommon Histological Variant and Review of Literature

Background

Teratoid hepatoblastoma is an uncommon but well-recognized variant of mixed hepatoblastoma.

Case report

A one-year female child presented with palpable and progressively increasing right abdominal mass for 3 months. The contrast-enhancing computed tomography (CECT) abdomen revealed a large heterogeneous hepatic mass measuring 12 × 6.6 × 6 cm. Histopathological examination of the resected specimen showed a mixed hepatoblastoma (epithelial and mesenchymal) with teratoid features and multi-lineage differentiation (all three germ cell layers). A focus showed embryonal rhabdomyosarcomatous element.

Conclusion

Teratoid hepatoblastoma can show a wide range of heterologous differentiation that may pose a significant diagnostic dilemma. Such a broad spectrum has not been described in the literature previously. An appropriate immunohistochemical panel may be needed to identify and delineate the various heterologous differentiation to clinch the correct diagnosis. Secondary somatic malignancy such as rhabdomyosarcoma can develop in a teratomatous element.

Liver Transplant Oncology: Towards Dynamic Tumor-Biology-Oriented Patient Selection

While liver transplantation was initially considered as a curative treatment modality only for hepatocellular carcinoma, the indication has been increasingly extended to other tumor entities over recent years, most recently to the treatment of non-resectable colorectal liver metastases. Although oncologic outcomes after liver transplantation (LT) are consistently good, organ shortage forces stringent selection of suitable candidates. Dynamic criteria based on tumor biology fulfill the prerequisite of an individual oncological prediction better than traditional morphometric criteria based on tumor burden. The availability of specific (neo-)adjuvant therapies and customized modern immunosuppression may further contribute to favorable post-transplantation outcomes on the one hand and simultaneously open the path to LT as a curative option for advanced stages of tumor patients. Herein, we provide an overview of the oncological LT indications, the selection process, and expected oncological outcome after LT.

Salvage Liver Transplant in the Treatment of a Child With Local Recurrence of Hepatoblastoma

Hepatoblastoma is the most common primary liver cancer of childhood, accounting for two-thirds of primary malignant hepatic neoplasms. Radical surgical removal combined with efficient chemotherapy is essential for cure. Despite a complete tumor resection, hepatoblastoma may recur as isolated local disease. Intrahepatic recurrence of hepatoblastoma after liver resection is among the indications for liver transplant. Here, we present a patient who underwent salvage liver transplant for the treatment of local recurrence of hepatoblastoma. A 13-year-old boy who was diagnosed with hepatocellular carcinoma arising from the left liver lobe and who had been treated with surgical resection was admitted to our outpatient oncology clinic for further evaluation because alpha-fetoprotein levels had started to increase after surgery. Histopathological reexamination of hemihepatectomy material showed a histological aspect of an epithelial hepatoblastoma. Magnetic resonance imaging revealed multifocal lesions in the right liver lobe compatible with local recurrence. Despite a favorable initial response to chemotherapy, the tumor showed progression with increased alpha-fetoprotein levels. The patient was deemed a viable candidate for an urgent liver transplant and underwent right lobe living donor liver transplant. He had excellent graft function without any complications or signs of malignancy in the last follow-up visit at 7 months posttransplant. Salvage liver transplant is a lifesaving and sometimes the only treatment option for patients with local recurrence of hepatoblastoma. Although transplant in the salvage setting has been associated with worse outcomes than primary transplant, recent data have indicated more favorable and acceptable outcomes. Further studies are warranted to better understand the role of salvage liver transplant in the treatment of hepatoblastoma. Early consultation with the liver transplant team is critical in children who are most likely to need extreme resection or liver transplant.

Predictors of survival following liver transplantation for pediatric hepatoblastoma and hepatocellular carcinoma: Experience from the Society of Pediatric Liver Transplantation (SPLIT)

Management of unresectable pediatric hepatoblastoma (HB) and hepatocellular carcinoma (HCC) remains challenging. The Society of Pediatric Liver Transplantation (SPLIT) database was used to study survival predictors in pediatric liver transplantation (LT) for HB and HCC. Event-free survival (EFS), associated risk factors, and postoperative complications were studied in children requiring LT for HB/HCC at 16 SPLIT centers. Three-year EFS was 81% for HB (n = 157) and 62% for HCC (n = 18) transplants. Of HB transplants, 6.9% were PRETEXT II and 15.3% were POST-TEXT I/II. Tumor extent did not impact survival (p = NS). Salvage (n = 13) and primary HB transplants had similar 3-year EFS (62% versus 78%, p = NS). Among HCC transplants, 3-year EFS was poorer in older patients (38% in ≥8-year-olds vs 86% <8-year-olds) and those with larger tumors (48% for those beyond versus 83% within Milan criteria, p = NS). Risk of infection (HR 1.5, 95% CI 1.1-2.2, p = .02) and renal injury (HR 2.4, 95% CI 1.7-3.3, p < .001) were higher in malignant versus nonmalignant LT. Survival is favorable for pediatric HB and HCC LT, including outcomes after salvage transplant. Unexpected numbers of LTs occurred in PRE/POST-TEXT I/II tumors. Judicious patient selection is critical to distinguish tumors that are potentially resectable; simultaneously, we must advocate for patients with unresectable malignancies to receive organs.

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.

Surgical Outcome of Children with a Malignant Liver Tumour in The Netherlands: A Retrospective Consecutive Cohort Study

Introduction: Six to eight children are diagnosed with a malignant liver tumour yearly in the Netherlands. The majority of these tumours are hepatoblastoma (HB) and hepatocellular carcinoma (HCC), for which radical resection, often in combination with chemotherapy, is the only curative treatment option. We investigated the surgical outcome of children with a malignant liver tumour in a consecutive cohort in the Netherlands. Methods: In this nationwide, retrospective observational study, all patients (age < 18 years) diagnosed with a malignant liver tumour, who underwent partial liver resection or orthotopic liver transplantation (OLT) between January 2014 and April 2021, were included. Children with a malignant liver tumour who were not eligible for surgery were excluded from the analysis. Data regarding tumour characteristics, diagnostics, treatment, complications and survival were collected. Outcomes included major complications (Clavien−Dindo ≥ 3a) within 90 days and disease-free survival. The results of the HB group were compared to those of a historical HB cohort. Results: Twenty-six children were analysed, of whom fourteen (54%) with HB (median age 21.5 months), ten (38%) with HCC (median age 140 months) and one with sarcoma and a CNSET. Thirteen children with HB (93%) and three children with HCC (30%) received neoadjuvant chemotherapy. Partial hepatic resection was possible in 19 patients (12 HB, 6 HCC, and 1 sarcoma), whilst 7 children required OLT (2 HB, 4 HCC, and 1 CNSET). Radical resection (R0, margin ≥ 1.0 mm) was obtained in 24 out of 26 patients, with recurrence only in the patient with CNSET. The mean follow-up was 39.7 months (HB 40 months, HCC 40 months). Major complications occurred in 9 out of 26 patients (35% in all, 4 of 14, 29% for HB). There was no 30- or 90-day mortality, with disease-free survival after surgery of 100% for HB and 80% for HCC, respectively. Results showed a tendency towards a better outcome compared to the historic cohort, but numbers were too small to reach significance. Conclusion: Survival after surgical treatment for malignant liver tumours in the Netherlands is excellent. Severe surgical complications arise in one-third of patients, but most resolve without long-term sequelae and have no impact on long-term survival.

Trans-Arterial Radioembolization with Yttrium-90 of Unresectable and Systemic Chemotherapy Resistant Hepatoblastoma in Three Toddlers

The aim of this short communication was to report the results of transarterial radioembolization (TARE) with Yttrium-90 (Y90) loaded resin microspheres in three toddlers with unresectable and systemic chemotherapy-resistant HB hepatoblastoma (HB). Six TARE procedures were performed on the patients. The dose required for treatment was calculated using partition model. Administered doses of Y90 were 1.369, 0.851, and 1.147 GBq. Complete radiological response in two patients and partial response enabling liver resection in one patient were achieved. Neither life-threatening nor minor complications developed after the treatment. These results demonstrates that HB is a radiosensitive neoplasm, and TARE-Y90 can be used as the primary, neoadjuvant and palliative treatment method in patients with unresectable and systemic chemotherapy-resistant HBs. However, studies with higher number of patients and long-term results are required.

Doxorubicin in combination with cisplatin, 5-flourouracil, and vincristine is feasible and effective in unresectable hepatoblastoma: A Children's Oncology Group study

BACKGROUND

The Children's Oncology Group (COG) adopted cisplatin, 5-flourouracil, and vincristine (C5V) as standard therapy after the INT-0098 legacy study showed statistically equivalent survival but less toxicity in comparison with cisplatin and doxorubicin. Subsequent experience demonstrated doxorubicin to be effective in patients with recurrent disease after C5V, and this suggested that it could be incorporated to intensify therapy for patients with advanced disease.

METHODS

In this nonrandomized, phase 3 COG trial, the primary aim was to explore the feasibility and toxicity of a novel therapeutic cisplatin, 5-flourouracil, vincristine, and doxorubicin (C5VD) regimen with the addition of doxorubicin to C5V for patients considered to be at intermediate risk. Patients were eligible if they had unresectable, nonmetastatic disease. Patients with a complete resection at diagnosis and local pathologic evidence of small cell undifferentiated histology were also eligible for an assessment of feasibility.

RESULTS

One hundred two evaluable patients enrolled between September 14, 2009, and March 12, 2012. Delivery of C5VD was feasible and tolerable: the mean percentages of the target doses delivered were 96% (95% CI, 94%-97%) for cisplatin, 96% (95% CI, 94%-97%) for 5-fluorouracil, 95% (95% CI, 93%-97%) for doxorubicin, and 90% (95% CI, 87%-93%) for vincristine. Toxicity was within expectations, with death as a first event in 1 patient. The most common adverse events were febrile neutropenia (n = 55 [54%]), infection (n = 48 [47%]), mucositis (n = 31 [30%]), hypokalemia (n = 39 [38%]), and elevated aspartate aminotransferase (n = 28 [27%]). The 5-year event-free and overall survival rates for the 93 patients who did not have complete resection at diagnosis were 88% (95% CI, 79%-93%) and 95% (95% CI, 87%-98%), respectively.

CONCLUSIONS

The addition of doxorubicin to the previous standard regimen of C5V is feasible, tolerable, and efficacious, and this suggests that C5VD is a good regimen for future clinical trials.

Feasibility of Real-Time Central Surgical Review for Patients with Advanced-Stage Hepatoblastoma in the JPLT3 Trial

In the JPLT3 study, a real-time central surgical reviewing (CSR) system was employed aimed at facilitating early referral of candidates for liver transplantation (LTx) to centers with pediatric LTx services. The expected consequence was surgery, including LTx, conducted at the appropriate time in all cases. This study aimed to review the effect of CSR on institutional surgical decisions in cases enrolled in the JPLT3 study. Real-time CSR was performed in cases in which complex surgeries were expected, using images obtained after two courses of preoperative chemotherapy. Using the cloud-based remote image viewing system, an expert panel consisting of pediatric and transplant surgeons reviewed the images and commented on the expected surgical strategy or the necessity of transferring the patient to a transplant unit. The results were summarized and reported to the treating institutions. A total of 41 reviews were conducted for 35 patients, and 16 cases were evaluated as possible candidates for LTx, with the treating institutions being advised to consult a transplant center. Most of the reviewed cases promptly underwent definitive liver surgeries, including LTx per protocol.

Waitlist mortality and post-liver transplant outcomes of pediatric patients with hepatocellular carcinoma and hepatoblastoma in the United States

BACKGROUND

Liver transplantation (LT) is offered in cases of advanced disease for both pediatric patients with hepatoblastoma (HBL) and those with hepatocellular carcinoma (HCC). Current United States organ allocation priorities differ between the two groups.

METHODS

We retrospectively examined the waitlist and posttransplant outcomes of pediatric LT candidates with HBL and HCC using the United Network for Organ Sharing registry (February 2002 to September 2020).

RESULTS

Six hundred sixty-eight children with HBL and 95 children with HCC listed for first LT were identified. Patients with HBL were younger (p < .001), had lower laboratory Model for End-stage Liver Disease (MELD)/Pediatric End-stage Liver Disease (PELD) scores (p < .001), and had lesser proportion with encephalopathy (p = .01). Patients with HCC had an increased risk of waitlist mortality in univariable (unadjusted subdistribution hazard ratio [sHR] = 4.37, 95% confidence interval [CI], 2.01-9.51, p < .001) and multivariable competing risk regression (adjusted sHR = 3.08, 95% CI 1.13-8.37, p = .03) accounting for age and laboratory MELD/PELD score. Five hundred ninety-five children underwent LT for HBL and 76 for HCC. Patients transplanted for HBL had a significantly higher proportion with status 1B exception (71.3% vs. 7.9%, p < .001). No difference was observed in patient (unadjusted log-rank test, p = .52; adjusted hazard ratio [HR] = 0.77, 95% CI, 0.40-1.48, p = .43) or graft survival (unadjusted log-rank test, p = .93; adjusted HR = 0.74, 95% CI 0.42-1.33, p = .32) between HCC and HBL recipients.

CONCLUSION

Waitlist mortality for pediatric LT candidates with HCC is significantly higher than for HBL, while posttransplant patient and graft survival are similar. This highlights an opportunity to improve equitable prioritization for children with HCC who may have reduced access to size-appropriate deceased donor organs and less effective bridge-to-transplant therapies.

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.

A retrospective study of clinical features and outcome in patients with refractory or recurrent hepatoblastoma: A single institution experience

BACKGROUND

Hepatoblastoma (HB) is the most common childhood primary hepatic malignancy. The overall survival rate in patients with HB has reached more than 80% over the past decades. The poor prognostic and high-risk HB have been defined, but the treatment and cure of refractory or relapsed HB is still an arduous task.

METHODS

The complete records of HB in patients under the age of 18 at the MacKay Memorial Hospital between 1990 and 2019 were examined.

RESULTS

The treatment results for 11 patients with refractory or relapsed HB are presented. The multi-modality treatment records were reviewed and the clinical characteristics associated with poor outcome included multifocal lesions, low α-fetoprotein, great vessel invasion and metastases. Delayed liver tumor surgery was carried out in eight cases. The median duration of follow-up for the 11 patients was 48.6 months (range 1.9 to 316.8 months). The 5-year and 10-year overall survival rate were 62.3% ± 15% (SE) and 49.9% ± 16.4% (SE), respectively. Most treatment-related toxicities were tolerable. The major concern during long term follow-up was irreversible high-frequency hearing loss.

CONCLUSION

Patients with refractory/relapsed HB are still a thorny issue and more research is needed to improve the outcome.

Feasibility of Nonanatomical Liver Resection in Diligently Selected Patients with Hepatoblastoma and Comparison of Outcomes with Anatomic Resection

INTRODUCTION

 Treatment guidelines for hepatoblastoma discourage nonanatomic liver resections. However, the evidence for this is inadequate and comes from a study performed almost two decades ago which additionally contained inherent limitations. This study aimed to assess the feasibility and oncologic outcomes of nonanatomic resections (NAR) performed in diligently selected patients and compare the results with anatomic resections (AR).

MATERIALS AND METHODS

 A total of 120 patients who underwent liver resections for hepatoblastoma between January 2008 and July 2019 were reviewed. Feasibility of NAR was based on postchemotherapy relations to vessels, site of the lesion, and possibility of achieving negative resection margins.

RESULTS

 AR was performed in 95 patients and 25 had NAR. The NAR cohort had similar International Childhood Liver Tumors Strategy Group (SIOPEL) risk group distribution. Blood loss and operative times were lower in patients undergoing NAR. No differences were noted between the two groups concerning postoperative morbidity and hospitalization. There were no pathologic positive margins or local recurrences in the NAR patients. Relapse free (RFS) and overall survival (OS) was similar in the two groups (p = 0.54 and 0.96, respectively). Subgroup analysis of only posttreatment extent of tumor (POSTTEXT) I and II patients also showed no difference in RFS or OS for the two groups with a persistent significant difference in operative times and blood loss.

CONCLUSION

 NAR is feasible with clear margins in carefully selected patients. It is not associated with more complications and outcomes are not inferior to AR. NAR is associated with lesser blood loss and operative time.

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.

Liver Tumours in Children: The Hepatologist's View

ABSTRACT

Diagnostic and therapeutic innovations have changed the way we now approach liver tumours in children and adolescents. Novel imaging tools, increasing awareness, and surveillance has led to early diagnosis of benign and malignant liver tumours. Multidisciplinary interventions have favourably altered the natural course in some liver tumours. The role of liver transplantation is expanding and has become fully integrated into today's therapeutic algorithms. Transarterial locoregional and ablation therapies have been successful in adults and are being explored in children to facilitate resectability and improve outcome. For the first time, North American, Japanese, and European experts have designed a global trial to optimize management of malignant liver tumours and aim to find signature molecular profiles that will translate to individualised treatment strategies.This article aims to offer an overview of recent advances in our understanding of liver tumours in children. It focuses on the paediatric hepatologist's view and their role in the multidisciplinary management of benign and malignant liver tumours.

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.

Transplant Oncology in Primary and Metastatic Liver Tumors: Principles, Evidence, and Opportunities

Transplant oncology defines any application of transplant medicine and surgery aimed at improving cancer patients' survival and/or quality of life. In practice, liver transplantation for selected hepato-biliary cancers is the only solid organ transplant with demonstrated efficacy in curing cancer. Four are the proposed future contributions of transplant oncology in hepato-biliary cancer (4-e). (1) evolutionary approach to cancer care that includes liver transplantation; (2) elucidation of self and non-self recognition systems, by linking tumor and transplant immunology; (3) exploration of innovative endpoints both in clinical and experimental settings taking advantage from the access to the entire liver explant; (4) extension of surgical limitation in the multidisciplinary approach to hepato-biliary oncology. The aim of this review is to define the principles of transplant oncology that may be applied to hepato-biliary cancer treatment and research, attempting to balance current evidences with future opportunities.

MDM4 inhibition: a novel therapeutic strategy to reactivate p53 in hepatoblastoma

Hepatoblastoma (HB) is the most common pediatric liver malignancy. High-risk patients have poor survival, and current chemotherapies are associated with significant toxicities. Targeted therapies are needed to improve outcomes and patient quality of life. Most HB cases are TP53 wild-type; therefore, we hypothesized that targeting the p53 regulator Murine double minute 4 (MDM4) to reactivate p53 signaling may show efficacy. MDM4 expression was elevated in HB patient samples, and increased expression was strongly correlated with decreased expression of p53 target genes. Treatment with NSC207895 (XI-006), which inhibits MDM4 expression, or ATSP-7041, a stapled peptide dual inhibitor of MDM2 and MDM4, showed significant cytotoxic and antiproliferative effects in HB cells. Similar phenotypes were seen with short hairpin RNA (shRNA)-mediated inhibition of MDM4. Both NSC207895 and ATSP-7041 caused significant upregulation of p53 targets in HB cells. Knocking-down TP53 with shRNA or overexpressing MDM4 led to resistance to NSC207895-mediated cytotoxicity, suggesting that this phenotype is dependent on the MDM4-p53 axis. MDM4 inhibition also showed efficacy in a murine model of HB with significantly decreased tumor weight and increased apoptosis observed in the treatment group. This study demonstrates that inhibition of MDM4 is efficacious in HB by upregulating p53 tumor suppressor signaling.

Upregulation of human endogenous retrovirus-K (HML-2) mRNAs in hepatoblastoma: Identification of potential new immunotherapeutic targets and biomarkers

PURPOSE

Hepatoblastoma is the most common liver malignancy in children. In order to advance therapy against hepatoblastoma, novel immunologic targets and biomarkers are needed. Our purpose in this investigation is to examine hepatoblastoma transcriptomes for the expression of a class of genomic elements known as Human Endogenous Retrovirus (HERVs). HERVs are abundant in the human genome and are biologically active elements that have been associated with multiple malignancies and proposed as immunologic targets in a subset of tumors. A sub-family of HERVs, HERV-K(HML-2) (HERV-K), have been shown to be tightly regulated in fetal development, making investigation of these elements in pediatric tumors paramount.

METHODS

We first created a HERVK-FASTA file utilizing 91 previously described HML-2 proviruses. We then concatenated the file onto the GRCh38.95 cDNA library from Ensembl. We used this reference database to evaluate existing RNA-seq data from 10 hepatoblastoma tumors and 3 normal liver controls (GEO accession ID: GSE8977575). Quantification and differential proviral expression analysis between hepatoblastoma and normal liver controls was performed using the pseudo-alignment program Salmon and DESeq2, respectively.

RESULTS

HERV-K mRNA was expressed in hepatoblastoma from multiple proviral loci. All expressed HERV-K proviral loci were upregulated in hepatoblastoma compared to normal liver controls. Five HERV-K proviruses (1q21.3, 3q27.2, 7q22.2, 12q24.33 and 17p13.1) were significantly differentially expressed (p-adjusted value <0.05, |log2 fold change| > 1.5) across conditions. The provirus at 17p13.1 had an approximately 300-fold increased expression in hepatoblastoma as compared to normal liver. This was in part due to the near absence of HERV-K mRNA at the 17p13.1 locus in fully differentiated liver samples.

CONCLUSIONS

Our investigation demonstrates that HERV-K is expressed from multiple loci in hepatoblastoma and that the expression is increased for several proviruses compared to normal liver controls. Our results suggest that HERV-K mRNA expression may be useful as a biomarker in hepatoblastoma, given the large differential expression profiles in hepatoblastoma, with very low mRNA levels in liver control samples.

Management of hepatoblastoma in the United States: Can we do better?

BACKGROUND

Hepatoblastoma is the most common type of liver cancer in children. Refined therapeutic approaches combining risk-adapted chemotherapy along with complete tumor resection has led to improved survival. We aimed to evaluate the current state of management and outcomes for hepatoblastoma in the United States.

METHODS

We retrospectively reviewed 794 children (<18 years) with hepatoblastoma from the National Cancer Database (2004-2015). We assessed overall survival by means of Kaplan-Meier method, log-rank tests, and multivariable Cox regression.

RESULTS

Median age was 1 year (interquartile range: 0-2) and 170 (21.4%) presented with metastatic disease. Surgical resection was included in the treatment of 614 (77.3%) children (resection in 66.8% and liver transplantation in 10.6%). In the entire cohort, 95.1% of children received chemotherapy. In the surgical cohort, 575 (93.6%) received chemotherapy (34.5% neoadjuvant, 28.7% adjuvant, 30.5% both neoadjuvant and adjuvant). The 5-year overall survival was 76.6% for the entire cohort (no-surgery group: 55.3% vs surgery group: 82.8%). In multivariable analysis for all children, age ≥8 years (P = .009), metastasis (P < .001), surgery only (P = .009), and chemotherapy only (P < .001) were risk factors for mortality. In multivariable analysis for the surgical cohort, metastasis (P = .001), multifocality (P = .02), no chemotherapy (P = .03), and margin-positive resection (P = .02) were risk factors for mortality.

CONCLUSION

Excellent long-term overall survival is achievable with a combination of chemotherapy and surgical resection when a negative resection margin is achieved. However, nearly a quarter of children never received surgical treatment, representing a potential opportunity for improvement in care.

A narrative review of the challenges and countermeasures in hepatoblastoma management during COVID-19 epidemic

An infectious disease named "coronavirus disease 2019" (COVID-19) currently has brought a threat to global health security and trends to be more and more severe in many countries. It also has introduced great challenges to the diagnosis and management of children with hepatoblastoma (HB). During the COVID-19 pandemic, pediatric surgeons should not only develop personalized treatment plans for HB therapy, but also emphasize the diagnosis, prevention, and treatment of this virus. Children with both HB and COVID-19 are recommended to undertake multidisciplinary assessment. Anti-SARS-CoV-2 therapy may be a preferred treatment for the infected without presenting a surgical emergency. However, emergent operation may be necessary for HB children with concurrent COVID-19 who developed a life-threatening surgical emergency condition. Otherwise, for children with negative virus examination results, treatment advice should be based on the impact of the epidemic and regional economic considerations. A "wait and see" strategy is recommended for children with resectable tumors after new adjuvant chemotherapy treatment (NACT). Assessment of liver transplantation is recommended for children with HB whose tumors cannot be resected after NACT. Children with HB with pulmonary metastasis may have abnormal findings on chest imaging due to COVID-19. Besides, the detailed therapeutic regimens may vary for children with HB with or without an emergency presentation. Based on previous consensus, current research, and the experiences of our hospital, we aim to offer available management plans for the above-mentioned concerns.

Survival and prognostic factors for childhood malignant liver tumors: analysis of harmonized clinical data

BACKGROUND

Despite overall striking advances in survival of childhood liver tumors, outcomes remain poor for specific patient segments. We aimed to assess overall survival (OS) of this rare disease and evaluate the generalizability of prognostic variables included in international collaborative systems using, for the first time, harmonized clinical data from two geographically different cohorts (Greece and Moscow).

METHODS

Data for children (0-14 years) with liver tumors were retrieved from two Southern-Eastern European areas (Greece; 2001-2019 and Moscow; 2012-2019). Kaplan-Meier curves were constructed, and OS values were derived from Cox proportional models controlling for study variables.

RESULTS

A total of 171 newly diagnosed cases (54.4% males) were included. The OS_5-year exceeded 80% in patients <5 years, reaching 85% among 133 patients with hepatoblastoma (HBL). By contrast, children with other than HBL histology, especially hepatocellular carcinoma (HCC) had significantly worse prognosis (hazard ratio [HR] _HCC: 7.09, 95% confidence intervals [CI]: 2.56-19.65; HR _{other liver tumors}: 5.18; 95%CI: 2.15-12.49). The OS_5-year was poorer (40%-60%) in patients with extensive local, metastatic or relapsed disease. By contrast, a significantly lower risk of death was shown in case of microscopically margin-negative resection (HR: 0.06, 95%CI: 0.02-0.17) and liver transplantation (HR: 0.12, 95% CI: 0.02-0.63) compared to the non- operated group.

CONCLUSIONS

Outcomes of patients with liver tumors registered in two SEE areas were comparable to those reported by major collaborative trials. Ongoing clinical cancer registration could facilitate comparison of outcomes between different study groups in order to shape state of the art of treatment.

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.

YTHDC1 gene polymorphisms and hepatoblastoma susceptibility in Chinese children: A seven-center case-control study

BACKGROUND

Hepatoblastoma is a commonly occurring embryonal tumors in children. N6-methyladenosine (m⁶ A) plays a critical role in gene expression, thus contributing to the occurrence and progression of cancer. RNA splicing is regulated by the nuclear m⁶ A reader YTHDC1, yet the roles of YTHDC1 polymorphisms in hepatoblastoma remain unclear.

METHODS

We conducted a seven-center case-control study to determine the association between YTHDC1 gene polymorphisms (rs2293596 T>C, rs2293595 T>C and rs3813832 T>C) and hepatoblastoma susceptibility. We recruited 313 hepatoblastoma patients and 1446 healthy controls.

RESULTS

There was no significant association between all of these polymorphisms and hepatoblastoma susceptibility in single locus or combined analysis. Stratification analysis revealed that rs2293596 TC/CC genotype carriers had a higher risk of developing hepatoblastoma in the subgroup of clinical stages III + IV [adjusted odds ratio (OR) = 1.80, 95% confidence interval (CI) = 1.18-2.76, p = 0.007]. In addition, 3 risk genotype carriers are more likely to develop hepatoblastoma in the subgroup of clinical stages III + IV (adjusted OR = 1.80, 95% CI = 1.18-2.76, p = 0.007). Furthermore, false-positive probability analysis was used to notarize our findings. Haplotype analysis indicated that there was no significant association between inferred haplotypes of YTHDC1 gene based on observed genotypes and hepatoblastoma risk.

CONCLUSIONS

In conclusion, our findings suggest that the rs2293596 T>C polymorphism may contribute to hepatoblastoma susceptibly and YTHDC1 gene polymorphisms may have a cumulative effect on hepatoblastoma risk.

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.