Liver Cancer In Children Research Articles

Hepatitis B immunization strategies and its associated factors: A narrative review.

Hepatitis B is a major public health concern as one third of the world's population is infected with hepatitis B virus (HBV). The risk of HBV infection remains primarily through percutaneous or mucosal contact with infected blood or body fluids. To update the society on hepatitis B immunization strategies and its associated factors. The review paper utilized different search engines such as Pubmed Central, Scopus, Web of Science, Google Scholar, and so onto conduct this review paper. Improving immunity through general vaccination recommendations has reduced the number of chronic hepatitis B cases among children and adolescents, but an influx of infections from endemic countries has increased the number of chronically infected adults. This is due to immigration from endemic countries to Hepatitis less burden areas like developed countries. Introduction of infant immunization programs in some countries has reportedly reduced the prevalence of HBV infection and reduced the incidence of liver cancer in children and young adults. While hepatitis B vaccination coverage is low, a significant number of people are not adhering to full hepatitis B vaccination posing a potential hazard to health.

A TGF-β-dominant chemoresistant phenotype of hepatoblastoma associated with aflatoxin exposure in children.

Hepatoblastoma (HB) is the most common liver cancer in children, posing a serious threat to children's health. Chemoresistance is the leading cause of mortality in patients with HB. A more explicit definition of the features of chemotherapy resistance in HB represents a fundamental urgent need. We performed an integrative analysis including single-cell RNA sequencing, whole-exome sequencing, and bulk RNA sequencing in 180 HB samples, to reveal genomic features, transcriptomic profiles, and the immune microenvironment of HB. Multicolor immunohistochemistry staining and in vitro experiments were performed for validation. Here, we reported four HB transcriptional subtypes primarily defined by differential expression of transcription factors. Among them, the S2A subtype, characterized by strong expression of progenitor ( MYCN , MIXL1 ) and mesenchymal transcription factors ( TWIST1 , TBX5 ), was defined as a new chemoresistant subtype. The S2A subtype showed increased TGF-β cancer-associated fibroblast and an immunosuppressive microenvironment induced by the upregulated TGF-β of HB. Interestingly, the S2A subtype enriched SBS24 signature and significantly higher serum aflatoxin B1-albumin (AFB1-ALB) level in comparison with other subtypes. Functional assays indicated that aflatoxin promotes HB to upregulate TGF-β. Furthermore, clinical prognostic analysis showed that serum AFB1-ALB is a potential indicator of HB chemoresistance and prognosis. Our studies offer new insights into the relationship between aflatoxin and HB chemoresistance and provide important implications for its diagnosis and treatment.

A population-based assessment of metastatic hepatoblastoma in Texas reveals ethnic disparities.

Hepatoblastoma (HB) is the most common primary liver cancer in children with emerging evidence that incidence is increasing globally. While overall survival for low risk hepatoblastoma is >90%, children with metastatic disease have worse survival. As identifying factors associated with high-risk disease is critical for improving outcomes for these children, a need for a further understanding of the epidemiology of hepatoblastoma is warranted. Therefore, we conducted a population-based epidemiologic study of hepatoblastoma in Texas, a large state characterized by ethnic and geographic diversity. Information on children diagnosed with hepatoblastoma at 0-19 years of age for the period of 1995-2018 was obtained from the Texas Cancer Registry (TCR). Demographic and clinical variables including sex, race/ethnicity, age at diagnosis, urban-rural status, and residence along the Texas-Mexico border were evaluated. Multivariable Poisson regression was used to calculate adjusted incidence rate ratios (aIRRs) and 95% confidence intervals (CIs) for each variable of interest. Joinpoint regression analysis was used to determine the trend in incidence of hepatoblastoma, overall and by ethnicity. Overall, 309 children diagnosed with hepatoblastoma in Texas for the period of 1995-2018. Joinpoint regression analysis showed no joinpoints in the overall or the ethnic-specific analyses. Over this period, the incidence increased at 4.59% annually; with the annual percent change higher among Latinos (5.12%) compared to non-Latinos (3.15%). Among these children, 57 (18%) had metastatic disease at diagnosis. Factors associated with hepatoblastoma included male sex (aIRR = 1.5, 95% CI: 1.2-1.8, p = 0.002); infancy (aIRR = 7.6, 95% CI: 6.0-9.7, p < 0.001); and Latino ethnicity (aIRR = 1.3, 95% CI: 1.0-1.7, p = 0.04). Additionally, children living in rural areas were less likely to develop hepatoblastoma (aIRR = 0.6, 95% CI: 0.4-1.0, p = 0.03). While residence on the Texas-Mexico border association with hepatoblastoma approached statistical significance (p = 0.06) in unadjusted models, this finding did not remain significant after adjusting for Latino ethnicity. The two factors associated with being diagnosed with metastatic hepatoblastoma included Latino ethnicity (aIRR = 2.1, 95% CI: 1.1-3.8, p = 0.02) and male sex (aIRR = 2.4, 95% CI: 1.3-4.3, p = 0.003). In this large population-based study of hepatoblastoma, we found several factors associated with hepatoblastoma and metastatic disease. The reasons for a higher burden of hepatoblastoma among Latino children is unclear but could be due to differences in geographic genetic ancestry, environmental exposures, or other unmeasured factors. Additionally, it is notable that Latino children were also more likely to be diagnosed with metastatic hepatoblastoma compared to non-Latino white children. To our knowledge, this has not been previously reported and warrants further study to delineate the causes of this disparity and identify interventions to improve outcomes.

Abstract A022: Role of imaging mass cytometry in studying hepatoblastoma vascular invasion

Abstract Introduction: Hepatoblastoma (HB) is the most common liver cancer in children with a survival rate of less than 50% in patients with high-risk disease, especially those with vascular invasion (VI). Patients with VI receive aggressive therapies that are toxic and ineffective; therefore, a better understanding of the biomarkers and biology of VI in HB is urgently needed. Methods: Using imaging mass cytometry (IMC) we analyzed 18 pre-validated protein targets on two of our formalin-fixed paraffin embedded (FFPE) HB patient samples; one with VI and one without VI. For confirmation of the proteins of interest, we performed immunohistochemistry (IHC) on primary and metastatic lesions from a separate patient. We performed RNA sequencing of one of our primary liver tumor and two sub-clones of that tumor, one inside an intrahepatic vessel and one sample representing tumor vessel thrombus. Results: By IMC, we found that protein expression of c-Myc and YAP-1 are increased in the areas of VI as the tumor invades the neighboring blood vessel. YAP-1 and c-Myc expression were low in the patient without VI. When examining the IHC of the separate patient with metastatic lung disease, we noted clear nuclear positivity of YAP-1 and c-Myc in the metastatic cells, compared to the negative nature of the primary liver tumor. Our RNA sequencing data showed that the average gene expression of c-Myc of the tumor in intrahepatic vessel and tumor vessel thrombus was 1.61 times higher than the primary tumor. The tumor found in the intrahepatic vessel and tumor vessel was found to have 1.29 times higher expression of Yap-1 compared to the primary tumor. Conclusions: YAP-1 and c-Myc had higher expression in hepatoblastoma as the tumor cells progress to invade the vasculature and metastasize. YAP-1 and c-Myc expression appears to play a role in vascular invasion that is maintained when tumors grow in the metastatic sites. Citation Format: Andres F. Espinoza, Roma Patel, Sarah Woodfield, Sanjeev A. Vasudevan. Role of imaging mass cytometry in studying hepatoblastoma vascular invasion [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr A022.

Deploying Indocyanine Green Fluorescence-Guided Navigation System in Precise Laparoscopic Resection of Pediatric Hepatoblastoma.

Background: Hepatoblastoma (HB) is the most common form of liver cancer in children. To date, complete tumor resection is still the gold standard for treating HB. Indocyanine green (ICG) has been identified as a sensitive adjunct that is highly effective in the identification and surgical management of local and metastatic HB. It has thus becomes an increasingly popular choice among surgeons in HB resection surgeries that are fluorescence-guided. However, laparotomy remains the preferred choice in most cases since the applications and limitations of fluorescence-guided laparoscopic surgery in treating HB remain unclear. In this study, the characteristics and outcomes of laparoscopic HB resections that were guided by intraoperative ICG fluorescent imaging were investigated. Methods: Seven HB patients underwent ICG-guided laparoscopic HB resection surgery from August 2019 to December 2021. ICG was intravenously administered to the patients at a dosage of 0.5 mg/kg 48 h prior to the scheduled operation. During operation, tumor localization and resection boundary were guided by fluorescence visualization. The data on surgical and clinical features were collected retrospectively. Results: The resection area and tumor boundary could be clearly viewed in real-time under the ICG fluorescence imaging navigation system during operation, except for one patient who had received interventional chemoembolization before surgery. The image produced by laparoscopic fluorescence navigation was clear since it was not affected by ambient light. All tumors were completely resected as confirmed by negative margins for HB during postoperative pathological examination. No residual or recurrence were also found through computed tomography during follow-up visits from 9 to 37 months. Conclusions: ICG fluorescence-guided laparoscopic surgery is safe and effective in treating HB due to its ability to provide clear information on tumor localization and delineate tumor margins in real-time.

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

Background & AimsHepatoblastoma (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.MethodsWe 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).ResultsMolecular 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.ConclusionsOur 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 summaryWe 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.

Competitive risk analysis of the therapeutic value of liver transplantation for liver cancer in children: A population-based study.

BackgroundLiver transplantation (LT) is one of the most important treatments for children with liver cancer (CLCa) and has been increasingly used. However, there is a lack of large-scale and multicenter studies on the trend in the application and value of LT for the treatment of CLCa.MethodsWe analyzed the clinicopathological data of CLCa from 2000 to 2018 from the Surveillance, Epidemiology, and End Results (SEER) database. We explored the trend in the application of LT for the treatment of CLCa. LASSO Cox regression and the Log-Rank test were used to explore prognostic factors, and we built a nomogram using the screened factors. Propensity score matching was used to balance the baseline data of patients undergoing LT and other surgeries, and then the Log-Rank test was used to evaluate the therapeutic value of LT for CLCa.ResultsThe 1-year, 3-year, 5-year, and 10-year overall survival (OS) rates of CLCa were 88.7%, 80.6%, 76.8%, and 73.0%, respectively. Then, we established a nomogram using many variables including age of diagnosis, regional lymph node metastasis, summary stage, and therapy. Internally validated and externally verified, our nomogram had good predictive power and clinical applicability. LT was increasingly being used to treat CLCa. There was no statistically significant difference in the OS of CLCa between the LT and other surgeries groups. After LT, the hepatoblastoma group had a better prognosis than the hepatocellular carcinoma group.ConclusionWe built a well-performing nomogram to predict the OS of CLCa. LT could improve the prognosis of CLCa as other surgeries and could be considered an effective treatment choice for CLCa.

Tumor-Background Ratio is an effective method to identify tumors and false-positive nodules in indocyanine-green navigation surgery for pediatric liver cancer.

BackgroundIndocyanine green (ICG) navigation surgery has been used for hepatoblastoma (HB) in children but the technique has been reported for using in other childhood liver cancers were rare. This article summarizes the application experience of ICG in HB and other childhood liver cancers in children and explores the role of fluorescence intensity measurement in identifying tumors.MethodsTo summarize the clinical experience of children with liver cancer treated by ICG navigation surgery. The tumor and its surrounding tissue were photographed by near infrared during the operation. The fluorescence intensity of tumors, ICG (+) lesions and the normal liver was measured, and the Tumor-Background Ratio (TBR) was calculated.ResultsA total of 11 children with liver cancer were injected intravenously with ICG 1 day before operation. With the help of ICG fluorescence navigation, there was no residual tumor at the surgical margin for all the children. Total fluorescence was seen in 2 cases, rim fluorescence in 2 cases, and partial fluorescence in 7 cases. 19 ICG false-positive nodules were found on the resection stump or residual liver tissue in 5 cases, and the TBR value of tumors was higher than that of false- positive nodules. 10 children have survived without disease.ConclusionICG navigation surgery is safe and feasible for liver cancer in children, which can enhance the visualization of the tumor during operation and provide more information about the location and boundaries of the tumor. This technique also has limitations, which can be affected by chemotherapy, tumor location, ICG administration regimen, and equipment. TBR is an effective method to identify tumor and non-cancerous lesions.

Liver Transplantation for Pediatric Hepatocellular Carcinoma: A Systematic Review.

Simple SummaryHepatocellular carcinoma is a type of primary liver cancer and the second most common type of liver cancer in children. Although partial hepatectomy can be curative, many children present with tumors that are not amenable to resection and thus the only potentially curative option is liver transplantation. In this systematic review, we have pooled the data from the worldwide literature and showed that survival after liver transplantation for pediatric hepatocellular carcinoma is favorable and many children do well even if their tumors exceed certain potentially restrictive criteria originally developed to select adults with hepatocellular carcinoma for liver transplantation.Liver transplantation (LT) is the only potentially curative option for children with unresectable hepatocellular carcinoma (HCC). We performed a systematic review of the MEDLINE, Scopus, Cochrane Library, and Web of Science databases (end-of-search date: 31 July 2020). Our outcomes were overall survival (OS) and disease-free survival (DFS). We evaluated the effect of clinically relevant variables on outcomes using the Kaplan–Meier method and log-rank test. Sixty-seven studies reporting on 245 children undergoing LT for HCC were included. DFS data were available for 150 patients and the 1-, 3-, and 5-year DFS rates were 92.3%, 89.1%, and 84.5%, respectively. Sixty of the two hundred and thirty-eight patients (25.2%) died over a mean follow up of 46.8 ± 47.4 months. OS data were available for 222 patients and the 1-, 3-, and 5-year OS rates were 87.9%, 78.8%, and 74.3%, respectively. Although no difference was observed between children transplanted within vs. beyond Milan criteria (p = 0.15), superior OS was observed in children transplanted within vs. beyond UCSF criteria (p = 0.02). LT can yield favorable outcomes for pediatric HCC beyond Milan but not beyond UCSF criteria. Further research is required to determine appropriate LT selection criteria for pediatric HCC.

Mitochondrial fragmentation is crucial for c-Myc-driven hepatoblastoma-like liver tumors

Hepatoblastoma is the most common liver cancer in children, and the aggressive subtype often has a poor prognosis and lacks effective targeted therapy. Although aggressive hepatoblastoma (HB) is often accompanied by abnormally high expression of the transcription factor c-Myc, the underlying mechanism remains unclear. In this study, we found that mitochondrial fragmentation was enhanced by c-Myc overexpression in human aggressive HB tissues and was associated with poor prognosis. Then, a mouse model resembling human HB was established via hydrodynamic injection of c-Myc plasmids. We observed that liver-specific knockout of the mitochondrial fusion molecule MFN1 or overexpression of mitochondrial fission molecule DRP1 promoted the occurrence of c-Myc-driven liver cancer. In contrast, when MFN1 was overexpressed in the liver, tumor formation was delayed. Invitro experiments showed that c-Myc transcriptionally upregulated the expression of DRP1 and decreased MFN1 expression through upregulation of miR-373-3p. Moreover, enhanced mitochondrial fragmentation significantly promoted aerobic glycolysis and the proliferation of HB cells by significantly increasing reactive oxygen species (ROS) production and activating the RAC-alpha serine/threonine-protein kinase (AKT)/mammalian target of rapamycin (mTOR) and nuclear factor κB (NF-κB) pathways. Taken together, our results indicate that c-Myc-mediated mitochondrial fragmentation promotes the malignant transformation and progression of HB by activating ROS-mediated multi-oncogenic signaling.

Analysis of survival rates and prognosis of hepatoblastoma in children: a retrospective study from a single center in China

Hepatoblastoma (HB) is the most common liver cancer in children, this study aims at analyzing the prognostic factors affecting the survival rates and summarizing the treatment experience. In this study, we reviewed patients with primary HB under the age of 14 years who underwent complete tumor resection from June 1997 to March 2019. The data of 72 patients were collected. Survival analysis was performed by Kaplan-Meier, multivariate Cox proportional hazards regression and linear mixed model for repeated measures (LMMRM). The 5-year and the 10-year event-free survival (EFS) of all patients were 78.2% and 73%, respectively. Both the 5-year and 10-year overall survival (OS) were 85.7%. Kaplan-Meier survival analysis showed that patients with tumor capsule infiltration (TCI) and patients with surgical margin less than 1 cm may also have a good prognosis. The Cox proportional hazards regression model analysis results were similar to the Kaplan-Meier analysis results. LMMRM analysis showed that there were significant differences in platelet, alpha-fetoprotein, C-reactive protein and hemoglobin values after surgery in the metastasis group (P < 0.05). This study suggests that patients with TCI or narrow surgical margin (<1 cm) may also have a good prognosis, and the risk stratification of HB can be used as the latest grading standard to evaluate the prognosis of patients.

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

BackgroundHepatoblastoma 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. MethodsWe 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. ResultsMedian 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. ConclusionExcellent 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.

Alternative hepatitis B vaccine strategies in healthy non-responders to a first standard vaccination scheme

Hepatitis B virus (HBV) infection is a major public health problem with an estimated 257 million people with chronic HBV infection and around 650 000 annual deaths due to long-term HBV-related liver disease (cirrhosis and hepatocellular carcinoma). 1 Whitford K Liu B Micallef J et al. Long-term impact of infant immunization on hepatitis B prevalence: a systematic review and meta-analysis. Bull World Health Organ. 2018; 96: 484-497 Crossref PubMed Scopus (25) Google Scholar Vaccination represents the cornerstone of public health measures to eradicate HBV. The implementation of effective infant vaccination programmes in many countries has resulted in a significant decrease in the prevalence of HBV infection and in the incidence of liver cancer in children and young adults. 1 Whitford K Liu B Micallef J et al. Long-term impact of infant immunization on hepatitis B prevalence: a systematic review and meta-analysis. Bull World Health Organ. 2018; 96: 484-497 Crossref PubMed Scopus (25) Google Scholar , 2 Schweitzer A Horn J Mikolajczyk RT Krause G Ott JJ Estimations of worldwide prevalence of chronic hepatitis B virus infection: a systematic review of data published between 1965 and 2013. Lancet. 2015; 386: 1546-1555 Summary Full Text Full Text PDF PubMed Scopus (1812) Google Scholar , 3 Wiesen E Diorditsa S Li X Progress towards hepatitis B prevention through vaccination in the Western Pacific, 1990–2014. Vaccine. 2016; 34: 2855-2862 Crossref PubMed Scopus (41) Google Scholar Serological response to three alternative series of hepatitis B revaccination (Fendrix, Twinrix, and HBVaxPro-40) in healthy non-responders: a multicentre, open-label, randomised, controlled, superiority trialRevaccinating healthy non-responders with Fendrix or HBVaxPro-40 resulted in significantly higher proportions of responders and therefore indication for these vaccines should be expanded to enable revaccination of non-responders. Full-Text PDF

APC germline hepatoblastomas demonstrate cisplatin-induced intratumor tertiary lymphoid structures

ABSTRACTHepatoblastoma (HB) is the most common liver cancer in children. We aimed to characterize HB related to APC (Adenomatous Polyposis Coli) germline mutation (APC-HB). This French multicentric retrospective study included 12 APC-HB patients under 5 at diagnosis. Clinical features of APC-HB were compared to the French SIOPEL2-3 cohort of HB patients. Molecular and histopathological analyses of APC-HB were compared to 15 consecutive sporadic HB treated at Bicêtre hospital from 2013 to 2015 (non-APC-HB). APC-HB patients have a peculiar spectrum of germline APC mutations, with no events in the main hotspot of classical APC mutations at codon 1309 (P < .05). Compared to sporadic HB, they have similar clinical features including good prognosis since all patients are alive in complete remission at last follow-up. APC-HB are mostly well-limited tumors with fetal predominance and few mesenchymal components. All APC-HB have an activated Wnt/β-catenin pathway without CTNNB1 mutation, confirming that germline APC and somatic CTNNB1 mutations are mutually exclusive (P < .001). Pathological reviewing identified massive intratumor tertiary lymphoid structures (TLS) containing both lymphocytes and antigen-presenting cells in all 11 APC-HB cases who received cisplatin-based neoadjuvant chemotherapy but not in five pre-chemotherapy samples (four paired biopsies and one patient resected without chemotherapy), indicating that these TLS are induced by chemotherapy (P < .001). Conclusion: APC-HB show a good prognosis, they are all infiltrated by cisplatin-induced TLS, a feature only retrieved in a minority of non-APC-HB. This suggests that APC inactivation can synergize with cisplatin to induce an immunogenic cell death that initiates an anti-tumor immune response.

YIA19-007: Patient-Derived Tumor Organoids for Drug Discovery of High-Risk Hepatoblastoma

Hepatoblastoma (HB), the most common liver cancer in children, has become the fastest growing pediatric cancer in the United States. The extent of tumor resection remains the most significant prognostic factor for HB, leaving children with unresectable HB limited treatment options and a largely stagnant survival rate below 40%. Due to the rareness and heterogeneity of this pediatric solid tumor, clinically-relevant, patient-derived models are in urgent need in order to develop more effective therapy for individual patients. Recent studies on many adult cancers have proven patient-derived organoids (PDOs) are faithful in vitro models mimicking disease biology and patient drug response. Via the support from a 2017 NCCN Young Investigator Award, our lab tested HB organoid culture using a large cohort of patient-derived xenografts (PDXs). To date, we have grown HB PDOs from PDXs derived from primary, metastatic, and recurrent tumors at 82% (11/14), 100% (7/7), and 100% (2/2) successful rate, respectively. These HB PDOs displayed histopathology consistent with that of their parental tumors. When we tested the first group of 6 PDO lines to the 10 drugs included in recently opened COG AHEP1531 clinical trial for pediatric liver cancer, we found 2 lines whose parental tumors did not respond to HB standard-of-care cisplatin. They showed the same resistance to cisplatin as well as 2 other platinum-based drugs, carboplatin and oxaliplatin. PDOs derived from 2 matched primary and metastatic tumors showed most similar overall response. These results provided encouraging evidence supporting the notion that HB PDOs mimic patient drug response. Intriguingly, in a subset of cisplatin-resistant HB PDOs, vincristine and gemcitabine showed strong antitumor activities, which we will further validate in vivo using a novel neonatal liver xenograft model developed in our lab. To accurately model the unique early developmental tumor microenvironment (TME) of HB, we have successfully engrafted HB cells into the liver of postnatal day 5–7 mice. We found TME of the neonatal liver, indeed, has a strong and unique metastasis-promoting effect compared to that of the adult liver. With this first PDO effort on pediatric HB and our exciting preliminary data, we are confident that we are approaching our long-term goal of building an integrated “HB PDO Clinic” to enable accurate evaluation of disease risk and therapeutic response to facilitate personalized HB patient care.

Effect of Population-Wide Hepatitis B Vaccination in Preventing Liver Cancer Among Children and Young Adults in the United States

Background: Liver cancer is the second most common cause of death from cancer worldwide1. In 2013, 79,2000 new cases of liver cancer and 818,000 deaths occurred globally2,3. Chronic infection with HBV accounts for at least 50% of liver cancer globally4. In the United States (US), liver cancer constitute the ninth leading cause of cancer death. The incidence of the cancer has persistently increased in the recent decades. Universal HBV vaccination was introduced in 1992 in the US. However, incidence trends of liver cancer among US children is poorly researched or relevant studies are not up-to-date5. Aim: This study aims to explore the effect of HBV population-wide vaccination program in reducing liver cancer incidence in the vaccinated children and adolescents in the US. Methods: Liver cancer incidence data were obtained from Cancer Incidence in Five Continents (CI5) databases (volumes I to X) from International Agency for Cancer Research (IARC). Data acquisition and analysis covered available incidence data between 1978-2007 from 9 cancer registries from Surveillance, Epidemiology, and End Results Program (SEER) from the US presented in the CI5 databases. Age-specific incidence rates of liver cancer (based on 5 year age groups ie 5-9 year, 10-14 year and 15-19 years) were calculated using age and sex-disaggregated incidence and population data from the SEER cancer registries. Stata software version 14.0 (StataCorp, USA) was used to calculate age-specific incidence rates, using number of liver cancer incident cases in each age group by the number of population in the respective age group. Age-specific rates were analyzed by period of diagnosis and by birth year. Rate ratios were estimated from age-group-specific Poisson regressions. Results: A total of 140 liver cancer incident cases were registered in the 9 SEER registries between 1978 to 2007 in the US. The incidence rate of liver cancer in children 5 to 9 years of age from 1978-1982 was 0.10 per 100,000 children. The incidence increased to 0.16 for the period from 2003-2007. The same trend is seen for the age group 10-14 and 15-19 years of age. Overall, age-specific incidence rates for liver cancer increased across age groups of 5-9, 10-14 and 15-19 year in the population covered by the 9 SEER registries in the US. However, risk estimates (incidence rate ratios, resulted from age-group-specific Poisson regressions did not show statistical significant effects. Conclusion: While the global response to implement population-wide HBV vaccination program is out of question, efforts to establish processes to evaluate the effect of such programs seems to be incomparably limited. Estimating the effect of HBV vaccination will relatively improve with time as further incidence data become available eg upon publication of data from new volume of CI5 databases.

Abstract B40: Model liver cancer metastasis using 3D spheroids derived from primary tumors in liver cancer genetic mouse models

Abstract Introduction: Liver cancer, predominantly hepatocellular carcinoma (HCC) in adults, has become the fastest-growing cause of cancer death in the United States. Most cases of HCC are diagnosed at the metastatic stage and have a 5-year survival rate below 3%. Liver cancer in children, most commonly hepatoblastoma (HB), has a better prognosis than in adults, but the 5-year survival falls from 70% to 30% if the tumor has disseminated. Without basic research into the biology of liver cancer metastasis, cure rates for this disease are unlikely to improve. Preclinical mouse models have played a central role in linking basic and translational cancer research. However, current mouse models of liver cancer have mostly addressed the early stages of the disease and have rarely focused on its metastatic forms. Accurate model systems of liver cancer metastasis are urgently needed to elucidate the associated cellular and molecular mechanisms. Methods: Metastasis-initiating cells often hijack normal stem cell pathways to gain survival and growth advantages. Recent advances in 3D stem cell spheroid culture have provided a means to rapidly select and propagate cancer cells with stemness potential for in-depth biologic analysis. We have previously generated two liver cancer genetic mouse models (GMMs) of HCC and HB, both of which developed frequent primary tumors in the liver but only rare metastases. Our laboratory recently developed a robust protocol for growing liver cancer spheroids (LCSs) from primary tumors in the two GMM using 3D stem cell culture. To evaluate the in vivo tumorigenicity of the LCSs, we developed a novel ultrasound-guided, noninvasive intrahepatic injection method for transplanting cells into the liver with high accuracy and minimal animal manipulation. Results: We found that a subset of LCSs from each model exhibited potent tumorigenicity, driving widespread metastases in vivo upon orthotopic transplant. Gene set enrichment analysis demonstrated substantial enrichment of a number of metastatic and recurrent human HCC gene signatures in the LCS-driven HCC tumors and the enrichment of a human HB gene signature in the LCS-driven HB tumors. A large RNA-seq transcriptomic analysis revealed a significant enrichment of inflammatory and extracellular processes in the metastatic LCSs and tumors they generated compared to their nonmetastatic counterparts in both models, suggesting a critical role of tumor microenvironment (TME) in liver cancer metastasis. Conclusion: Our LCS-based approach to model liver cancer metastasis represents a unique strategy to model liver cancer metastasis by using primary tumors from non- or low-metastatic GMMs, an approach that can potentially be extended to other cancer types, considering the rapid advances in cancer spheroid studies across a wide range of solid malignant tumors. It also permits rapid mechanistic studies of liver cancer metastasis in the future by allowing gene manipulation in vitro within a uniform population of tumor-derived, metastasis-initiating LCSs, with subsequent tracking of metastasis development in transplantation models to be built in disease-relevant TMEs. Citation Format: Liyuan Li, Maoxiang Qian, David Finkelstein, Melissa Johnson, Dolores H. López-Terrada, Liqin Zhu. Model liver cancer metastasis using 3D spheroids derived from primary tumors in liver cancer genetic mouse models [abstract]. In: Proceedings of the AACR Special Conference: Advances in Modeling Cancer in Mice: Technology, Biology, and Beyond; 2017 Sep 24-27; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(10 Suppl):Abstract nr B40.

Abstract A10: Epigenetic mechanisms in liver tumors: Gene expression analysis of epigenetic machinery in hepatoblastomas

Abstract Liver tumors in children are rare and account for only 1-4% of all pediatric solid tumors. While hepatocellular carcinoma is predominant in adults, the most common liver cancer in children is hepatoblastoma, an embryonal tumor. The prognosis of patients with advanced tumor stages remains poor as well as surviving children often face severe effects following aggressive chemotherapy. Hepatoblastomas carry a low mutational burden, and the impairment of epigenetic mechanisms, which are the core of embryogenesis and development, stands out as an alternative route for tumorigenesis. The main objective of this study was to explore the role of genes associated with methylation and hydroxymethylation in hepatoblastomas. The expression of seven genes of the epigenetic machinery (DNMT1, DNMT3A, DNMT3L, UHRF1, TET1, TET2, and TET3) was analyzed by qPCR (Taqman). The cohort of tumors consisted of 21 hepatoblastomas and a control group of 8 non-tumor differentiated liver tissues. Additionally, a 5hmC quantification assay (Quest 5-hmC DNA ELISA Kit) was applied to assess the level of 5hmC in tumors. TET1 and TET2 genes, whose proteins are responsible for the active demethylation of 5-methylcytosine (5mC), and consequent production of 5-hydroxymethylcytosine (5hmC), were found to be upregulated. A significant increase in the 5hmC levels was also evident in tumor samples when compared to nontumoral tissues. We have shown in hepatoblastomas an upregulated profile of TET1 and TET2 enzymes with a resulting elevation of 5hmC level in tumors. Our data suggest that hepatoblastomas could present a pluripotency pattern of gene expression when compared to differentiated livers; to address this issue, the expression levels of three genes associated with pluripotency (POU5F1, SOX2 and NANOG) were evaluated, with no significant alteration. Therefore, although hepatoblastomas have a more undifferentiated molecular profile than mature hepatocytes, our results indicate that tumor cells are already commited with the differentiation process. Altogether, these data suggest that the development of hepatoblastomas is associated with a blockage in the stages of hepatoblasts. Citation Format: Maria Rivas, Cecília da Costa, Silvia Toledo, Monica Cypriano, Luiz Caires, Ernesto Goulart, Dirce Carraro, Isabela Werneck, Carla Rosenberg, Mayana Zatz, Ana Krepischi. Epigenetic mechanisms in liver tumors: Gene expression analysis of epigenetic machinery in hepatoblastomas [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr A10.

Glypican 3 as a Serum Marker for Hepatoblastoma

Hepatoblastoma (HB) is the most common primary liver cancer in children. The conventional serum marker for HB, alpha-fetoprotein (AFP), has its limitations. Novel serum markers need to be explored. Glypican 3 (GPC3) has been reported to be an excellent histological immunomarker for HB. However, the clinical value of serum GPC3 in patients with HB is unknown. A total of 184 serum samples were tested for both GPC3 by ELISA, and AFP by immunometric assay. Of these, 134 were from 32 patients with HB at three treatment stages, 30 from age-matched patients with benign hepatobiliary disorders (BHD) and 20 from age-matched “normal controls”(NC). We found that the GPC3 levels in HB pretreatment group were significantly higher than those in NC group and HB remission group but not statistically different from those in BHD group and HB during treatment group. In contrast, AFP showed significant differences among different groups. The areas under the receiver operating curve (AUROC) value, sensitivity and specificity of GPC3 for HB pretreatment group versus all controls were all significantly lower than those of AFP. Serum GPC3 levels were not associated with prognostic parameters. We concluded that GPC3 is inferior to AFP as a serum marker for HB.

Genomic analysis of hepatoblastoma identifies distinct molecular and prognostic subgroups.

Analysis of immunohistochemical assays using antibodies targeting these genes in a prospective study of 35 HBs suggested that these candidate biomarkers have the potential to improve risk stratification and guide treatment decisions for HB patients at diagnosis; our results pave the way for clinical collaborative studies to validate candidate biomarkers and test their potential to improve outcome for HB patients. (Hepatology 2017;65:104-121).