Children's Oncology Group's 2023 blueprint for research: Surgery.

Surgery plays a crucial role in the treatment of children with solid malignancies. A well-conducted operation is often essential for cure. Collaboration with the primary care team is important for determining if and when surgery should be performed, and if performed, an operation must be done in accordance with well-established standards. The long-term consequences of surgery also need to be considered. Indications and objectives for a procedure vary. Providing education and developing and analyzing new research protocols that include aims relevant to surgery are key objectives of the Surgery Discipline of the Children's Oncology Group. The critical evaluation of emerging technologies to ensure safe, effective procedures is another key objective. Through research, education, and advancing technologies, the role of the pediatric surgeon in the multidisciplinary care of children with solid malignancies will continue to evolve.

EZH2 is a key component of hepatoblastoma tumor cell growth.

BACKGROUND: Enhancer of zeste homolog 2 (EZH2) catalyzes the trimethylation of histone H3 at lysine 27 via the polycomb recessive complex 2 (PRC2) and plays a time-specific role in normal fetal liver development. EZH2 is overexpressed in hepatoblastoma (HB), an embryonal tumor. EZH2 can also promote tumorigenesis via a noncanonical, PRC2-independent mechanism via proto-oncogenic, direct protein interaction, including ß-catenin. We hypothesize that the pathological activation of EZH2 contributes to HB propagation in a PRC2-independent manner. METHODS AND RESULTS: We demonstrate that EZH2 promotes proliferation in HB tumor-derived cell lines through interaction with ß-catenin. Although aberrant EZH2 expression occurs, we determine that both canonical and noncanonical EZH2 signaling occurs based on specific gene-expression patterns and interaction with SUZ12, a PRC2 component, and ß-catenin. Silencing and inhibition of EZH2 reduce primary HB cell proliferation. CONCLUSIONS: EZH2 overexpression promotes HB cell proliferation, with both canonical and noncanonical function detected. However, because EZH2 directly interacts with ß-catenin in human tumors and EZH2 overexpression is not equal to SUZ12, it seems that a noncanonical mechanism is contributing to HB pathogenesis. Further mechanistic studies are necessary to elucidate potential pathogenic downstream mechanisms and translational potential of EZH2 inhibitors for the treatment of HB.

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.

Vincristine/irinotecan/temsirolimus upfront window treatment of high-risk hepatoblastoma: A report from the Children's Oncology Group AHEP0731 Study Committee.

BACKGROUND: Survival for children with metastatic hepatoblastoma (HB) remains suboptimal. We report the response rate and outcome of two courses of vincristine/irinotecan/temsirolimus (VIT) in children with high-risk (HR)/metastatic HB. PROCEDURES: Patients with newly diagnosed HB received HR window chemotherapy if they had metastatic disease or a serum alpha-fetoprotein (AFP) level less than 100 ng/mL. Patients received vincristine (days 1 and 8), irinotecan (days 1-5), and temsirolimus (days 1 and 8). Cycles were repeated every 21 days. Responders had either a 30% decrease using RECIST (Response Evaluation Criteria in Solid Tumors) criteria OR a 90% (>1 log10 decline) AFP decline after two cycles. Responders received two additional cycles of VIT intermixed with six cycles of cisplatin/doxorubicin/5-fluorouracil/vincristine (C5VD). Nonresponders received six cycles of C5VD alone. RESULTS: Thirty-six eligible patients enrolled on study. The median age at enrollment was 27 months (range: 7-170). Seventeen of 36 patients were responders (RECIST and AFP = 3, RECIST only = 4, AFP only = 10). The median AFP at diagnosis was 222,648 ng/mL and the median AFP following two VIT cycles was 19,262 ng/mL. Three-year event-free survival was 47% (95% confidence interval [CI]: 30%-62%), while overall survival was 67% (95% CI: 49%-80%). CONCLUSION: VIT did not achieve the study efficacy endpoint. Temsirolimus does not improve the response rate seen in patients treated with vincristine and irinotecan (VI) alone as part of the initial treatment regimen explored in this study. Additionally, AFP response may be a more sensitive predictor of disease response than RECIST in HB.

10 Year Analysis of Pediatric Surgery Fellowship Match and Operative Experience: Concerning Trends?

OBJECTIVE: This paper aims to evaluate the pediatric surgery training pipeline vis-à-vis the pediatric surgery match and operative experience of pediatric surgery fellows. SUMMARY OF BACKGROUND DATA: Pediatric surgery remains a competitive surgical subspecialty. However, there is concern that operative experience for pediatric surgery fellows is changing. This paper examines the selectivity of the pediatric surgery match, along with the operative experience of pediatric surgery fellows to characterize the state of pediatric surgery training. METHODS: The pediatric surgery fellowship match was analyzed from the National Resident Matching Program data from 2010 to 2019. Selectivity among fellowships was compared using analysis of variance with Dunnett test. Operative log data for pediatric fellows was analyzed using the Accreditation Council for Graduate Medical Education case logs from 2009 to 2019. Linear regression analysis was used to evaluate trends in operative volume over time. RESULTS: Pediatric surgery had the highest proportion of unmatched applicants (47.2% ± 5.3%) and lowest proportion of unfilled positions (1.4% ± 1.6%) when compared to other National Resident Matching Program surgical fellowships. Accreditation Council for Graduate Medical Education case log analysis revealed a statistically significant decrease in cases for graduating fellows (-5.3 cases/year, P < 0.05). Total index cases decreased (-4.7 cases/year, P < 0.01, R 2 = 0.83) such that graduates in 2019 completed 59 fewer index operations than graduates in 2009. CONCLUSION: Although pediatric surgery fellowship remains highly selective there has been a decline in the operative experience for graduating fellows. This highlights the need for evaluation of training paradigms and operative exposure in pediatric surgery to ensure the training of competent pediatric surgeons.

The Outcome of Patients With Cystic Biliary Atresia With Intact Proximal Hepatic Ducts Following Hepatic-Cyst-Jejunostomy.

OBJECTIVES: To determine the outcomes of patients with cystic biliary atresia by correlating the anatomy of the hepatic ducts with the choice of biliary reconstruction surgery. BACKGROUND: The Kasai hepatoportoenterostomy (Kasai) is the initial surgical procedure offered to most patients with biliary atresia. In contrast, a hepatic-cyst-jejunostomy has been reported to be effective in patients with the cystic form of biliary atresia. METHODS AND RESULTS: We performed an international multicenter retrospective review. Two hundred eighty-seven patients were included, and 33 cases of cystic biliary atresia were identified. Outcomes were the serum total bilirubin level 3 months post-surgery and native liver survival at 2 years of age and were compared between cases who received the Kasai versus hepatic-cyst-jejunostomy in correlation to the anatomy of proximal hepatic ducts. The patients were categorized into 3 anatomical groups: patent intact hepatic ducts (n = 10), patent hypoplastic hepatic ducts (n = 13), and obliterated hepatic ducts (n = 10). All 10 patients with patent intact hepatic duct group underwent hepatic-cyst-jejunostomy, and 9 experienced bile drainage and native liver survival. Among the 13 patients with hypoplastic hepatic ducts, 11 underwent the Kasai procedure, and 9 had bile drainage, whereas 2 underwent hepatic-cyst-jejunostomy, and one survived with the native liver. All of the patients with obliterated hepatic ducts underwent the Kasai procedure; 5 established biliary drainage and survived with the native liver. Of 5 who did not drain, 3 underwent liver transplantation. CONCLUSIONS: In patients with cystic biliary atresia, the subset with a connection between cyst and intrahepatic bile ducts via intact proximal hepatic ducts had favorable clinical outcomes following hepatic-cyst-jejunostomy.

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.

Urinary 11-dehydrothromboxane B2 aspirin efficacy testing is sensitive to perioperative inflammation in pediatric solid-organ transplant patients.

BACKGROUND: Evidence for aspirin efficacy testing in pediatrics is limited, especially outside of cardiology, yet thrombotic events have high morbidity in other areas such as pediatric transplant surgery. Debates about whether thromboembolic events while on aspirin represent "aspirin resistance" or "high on-treatment platelet reactivity" persist, given the poor intertest agreement between testing platforms. PROCEDURE: This prospective observational study involved measuring aspirin efficacy using ex vivo testing of platelet aggregation (VerifyNow-Aspirin, VN) and urine 11-dehydrothromboxane B2 (AsprinWorks, UTxB2) contemporaneously at up to three time points after major noncardiac organ transplant surgery. The collection days (CD) were the second and seventh days after stable aspirin dosing and then a convalescent time point 2-9 months later. RESULTS: Fifty-five participants (age range, 0-21 years) were enrolled, having undergone total pancreatectomy with islet autotransplantation (N = 36), orthotopic liver transplantation (N = 18), and combined liver-kidney transplantation (N = 1). Platelet reactivity measured by VN remained unchanged, whereas UTxB2, which was elevated postoperatively, decreased significantly from CD1 to CD2 and CD3. Discordance in therapeutic efficacy was noted per manufacturer cutoffs, with therapeutic VN results in 86% of tests, whereas 12% of UTxB2 were therapeutic. Age-based stratification of UTxB2 results using previously published pediatric median levels increased overall UTxB2 therapeutic rates (80%) and intertest concordance (67% vs 27% if using adult range). No thrombotic events were observed. CONCLUSIONS: Our data suggest that urine thromboxane production may be an underappreciated reflection of postoperative inflammation. Validation of pediatric normal ranges for UTxB2 is a critical next step.

Developing an adolescent and adult Fontan Management Programme.

Patients with single-ventricle CHD undergo a series of palliative surgeries that culminate in the Fontan procedure. While the Fontan procedure allows most patients to survive to adulthood, the Fontan circulation can eventually lead to multiple cardiac complications and multi-organ dysfunction. Care for adolescents and adults with a Fontan circulation has begun to transition from a primarily cardiac-focused model to care models, which are designed to monitor multiple organ systems, and using clues from this screening, identify patients who are at risk for adverse outcomes. The complexity of care required for these patients led our centre to develop a multidisciplinary Fontan Management Programme with the primary goals of earlier detection and treatment of complications through the development of a cohesive network of diverse medical subspecialists with Fontan expertise.

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.

Relation of Liver Volume to Adverse Cardiovascular Events in Adolescents and Adults With Fontan Circulation.

Elevated central venous pressure in those with Fontan circulation causes liver congestion and hepatomegaly. We assessed if liver volume by magnetic resonance imaging (MRI) is associated with adverse cardiovascular outcomes. Retrospective study of 122 patients with Fontan circulation who were >10 years old and had a liver MRI with magnetic resonance elastography. Liver volume (ml) was measured by manual segmentation from axial T2-weighted images and was indexed to body surface area. The composite outcome included death, heart transplant, ventricular assist device placement, or nonelective cardiovascular hospitalization. The median age at the time of MRI was 18.9 (interquartile range 15.8 to 25.9) years, and 47% of the patients were women. The mean indexed liver volume was 1,133 ± 180 ml/m2. Indexed liver volume was not significantly associated with age, years since Fontan, or with liver stiffness (r = 0.15, p = 0.10), but was positively correlated with Fontan pressure (r = 0.32, p = 0.002). Over a median follow-up of 2.1 (0.8 to 4.2) years, 32 patients (26%) experienced the composite outcome. Higher indexed liver volume was associated with a greater hazard for the composite outcome (hazard ratio per 1 SD increase = 1.74, 95% confidence interval 1.27 to 2.35, p = 0.0004) but increased liver stiffness was not significantly associated with the composite outcome (hazard ratio per 1 SD increase 1.44, 95% confidence interval 0.90 to 2.21, p = 0.11). In conclusion, greater liver volume indexed to body surface area is associated with unfavorable hemodynamics and adverse outcomes in patients with Fontan circulation. Liver volume may be a useful, simple imaging biomarker in adolescents and adults with Fontan circulation.

Isolation and Culturing Primary Chaolangiocytes from Mouse Liver.

Cholangiocytes are epithelial cells lining the intrahepatic and extrahepatic bile ducts. Cholangiocytes perform key physiological functions in the liver. Bile synthesized by hepatocytes is secreted into bile canaliculi, further stored in the gallbladder, and finally discharged into the duodenum. Due to liver injury, biliary epithelial proliferate in response to endogenous or exogenous signals leading to cholangiopathies, inflammation, fibrosis, and cholangiocarcinoma. Cholangiocytes exhibit anatomical and functional heterogeneity, and understanding such diversified functions will potentially help in finding effective therapies for various cholestatic liver diseases. To perform such functional studies, effective cholangiocyte isolation and culture procedures are needed. This protocol will aid in easy isolation and expansion of cholangiocytes from the liver.

Indocyanine green is a sensitive adjunct in the identification and surgical management of local and metastatic hepatoblastoma.

BACKGROUND: Hepatoblastoma is the most common primary pediatric liver malignancy. Indocyanine green (ICG) has been described as an adjunct to resection in small series. Its utility remains undefined in larger cohorts. METHODS: Records for 29 patients diagnosed with hepatoblastoma who received ICG prior to surgical resection from 2017 to 2020 at a single institution were retrospectively reviewed. The primary outcome was correlation between intraoperative ICG-avidity and histologic presence of hepatoblastoma. A secondary outcome included the histologic margin designation for resected liver specimens. RESULTS: ICG sensitivity was 91% for 120 resected thoracic specimens from 21 patients. Specificity was 57%. In 10% of operations, HB-positive specimens were resected solely on ICG-avidity. In an additional 40% of cases, ICG assisted in localizing a preoperatively diagnosed lesion. ICG sensitivity during thoracotomy and thoracoscopic surgery was 95 and 74%, respectively; primary and relapsed disease demonstrated sensitivity of 94 and 73%, respectively. Sensitivity was 92% for 25 resected liver specimens from nine patients with all parenchymal margins grossly negative for disease. Four multifocal lesions were identified with two resected solely by ICG-avidity. CONCLUSIONS: ICG is a sensitive adjunct for identifying local and metastatic hepatoblastoma, including lesions not visualized on preoperative imaging, and delineating margins during liver resection. False positives limit specificity; however, there were no adverse outcomes from additional resections. We noted that thoracoscopic surgery can be completed safely in patients with less significant disease burden, and conversion to thoracotomy, if necessary, is straightforward.

Natural Course of Pediatric Portal Hypertension.

The etiology of portal hypertension (pHTN) in children differs from that of adults and may require different management strategies. We set out to review the etiology, management, and natural history of pHTN at a pediatric liver center. From 2008 to 2018, 151 children and adolescents with pHTN were identified at a free-standing children's hospital. Patients were stratified by etiology of pHTN (intrahepatic disease [IH], defined as cholestatic disease and fibrotic or hepatocellular disease; extrahepatic disease [EH], defined as hepatic vein obstruction and prehepatic pHTN). Patients with EH were more likely to undergo an esophagoduodenscopy for a suspected gastrointestinal bleed (77% vs. 41%; P < 0.01). Surgical interventions differed based on etiology (P < 0.01), with IH more likely resulting in a transplant only (65%) and EH more likely to result in a shunt only (43%); 30% of patients with IH and 47% of patients with EH did not undergo an intervention for pHTN. Kaplan-Meier analysis revealed a significant increase in mortality in the group that received no intervention compared to shunt, transplant, or both and lower mortality in patients with prehepatic pHTN compared to other etiologies (P < 0.01 each). Multivariate analysis revealed increased odds of mortality in patients with refractory ascites (odds ratio [OR], 4.34; 95% confidence interval [CI], 1.00, 18.88; P = 0.05) and growth failure (OR, 13.49; 95% CI, 3.07, 58.99; P < 0.01). Conclusion: In this single institution study, patients with prehepatic pHTN had better survival and those who received no intervention had higher mortality than those who received an intervention. Early referral to specialized centers with experience managing these complex disease processes may allow for improved risk stratification and early intervention to improve outcomes.

Evaluation of the diagnostic biopsy approach for children with hepatoblastoma: A report from the children's oncology group AHEP 0731 liver tumor committee.

BACKGROUND: The histopathological assessment of pediatric liver tumors at presentation is critical to establish a diagnosis, guide treatment, and collect appropriate research samples. The purpose of this study was to evaluate complications associated with different approaches to liver biopsy for newly diagnosed hepatoblastoma. METHODS: Children with hepatoblastoma were enrolled on Children's Oncology Group study AHEP0731 (September 2009-March 2012). This analysis evaluated the study cohort of initially unresectable patients who therefore underwent a biopsy procedure at diagnosis. The primary endpoint was clinically significant postbiopsy hemorrhage, defined as requiring red blood cell transfusion. RESULTS: We identified 121 children who underwent open (n = 76, 63%), laparoscopic (n = 17, 14%), or percutaneous (n = 28, 23%) liver biopsies. All biopsy procedures yielded adequate tissue for diagnosis. Postbiopsy hemorrhage requiring transfusion occurred after 26% (n = 31) of biopsies. Need for blood product transfusion most frequently occurred following open (n = 27/76, 36%) and laparoscopic (n = 4/17, 24%) biopsies, compared with percutaneous (n = 0/28, 0%) biopsies (p < 0.01). CONCLUSIONS: Pretreatment biopsy of pediatric liver tumors via a percutaneous approach yielded the lowest frequency of clinically significant hemorrhage requiring transfusion, without evidence of sacrificing diagnostic accuracy. LEVEL OF EVIDENCE: Level I.

Prospective Assessment of Ultrasound Shear Wave Elastography for Discriminating Biliary Atresia from other Causes of Neonatal Cholestasis.

OBJECTIVE: To prospectively assess the diagnostic performance of ultrasound shear wave elastography (SWE) and hepatobiliary laboratory biomarkers for discriminating biliary atresia from other causes of neonatal cholestasis. STUDY DESIGN: Forty-one patients <3 months of age with neonatal cholestasis (direct bilirubin >2 mg/dL) and possible biliary atresia were prospectively enrolled. Both 2-dimensional (2D) and point ultrasound SWE were performed prior to knowing the final diagnosis. Median 2D (8) and point (10) shear wave speed measurements were calculated for each subject and used for analyses. The Mann-Whitney U test was used to compare shear wave speed and laboratory measurements between patients with and without biliary atresia. Receiver operating characteristic curve analyses and multivariable logistic regression were used to evaluate diagnostic performance. RESULTS: Thirteen subjects (31.7%) were diagnosed with biliary atresia, and 28 subjects (68.3%) were diagnosed with other causes of neonatal cholestasis. Median age at the time of ultrasound SWE was 37 days. Median 2D (2.08 vs 1.49 m/s, P = .0001) and point (1.95 vs 1.21 m/s, P = .0014) ultrasound SWE measurements were significantly different between subjects with and without biliary atresia. Using a cut-off value of >1.84 m/s, 2D ultrasound SWE had a sensitivity = 92.3%, specificity = 78.6%, and area under the receiver operating characteristic curve (AuROC) of 0.89 (P < .0001). Using a cut-off value of >320 (U/L), gamma-glutamyl transferase (GGT) had a sensitivity = 100.0%, specificity = 77.8%, and AuROC of 0.85 (P < .0001). Multivariable logistic regression demonstrated an AuROC of 0.93 (P < .0001), with 2 significant covariates (2D ultrasound SWE [OR = 23.06, P = .01]; GGT [OR = 1.003, P = .036]). CONCLUSIONS: Ultrasound SWE and GGT can help discriminate biliary atresia from other causes of neonatal cholestasis.

Minimal adjuvant chemotherapy for children with hepatoblastoma resected at diagnosis (AHEP0731): a Children's Oncology Group, multicentre, phase 3 trial.

BACKGROUND: Hepatoblastoma treatment with curative intent requires surgical resection, but only about a third of newly diagnosed patients with hepatoblastoma have resectable disease at diagnosis. Patients who have upfront resection typically receive a total of 4-6 cycles of adjuvant chemotherapy post-surgery, with the combination of cisplatin, fluorouracil, and vincristine. We aimed to investigate whether event-free survival in children with hepatoblastoma who had complete resection at diagnosis could be maintained with two cycles of adjuvant chemotherapy. METHODS: In this Children's Oncology Group, multicentre, phase 3 trial, patients were enrolled in four risk groups on the basis of Evans surgical stage, tumour histology, and levels of α-fetoprotein at diagnosis to receive risk-adapted therapy. Here, we report on the low-risk stratum of the trial. Eligible patients were younger than 21 years and had histologically confirmed, stage I or II hepatoblastoma without 100% pure fetal stage I or small-cell undifferentiated histology; elevated serum α-fetoprotein level (>100 ng/mL); a complete resection at diagnosis; at least 50% Karnofsky (patients >16 years) or Lansky (patients ≤16 years) performance status; and had received no previous chemotherapy or other hepatoblastoma-directed therapy. Patients received two 21-day cycles of cisplatin, fluorouracil, and vincristine within 42 days of resection, consisting of cisplatin (100 mg/m2 per dose or 3·3 mg/kg per dose for children <10 kg) intravenously over 6 h on day 1; fluorouracil (600 mg/m2 per dose or 20 mg/kg per dose for children <10 kg) intravenous push on day 2; and vincristine (1·5 mg/m2 per day to a maximum dose of 2 mg, or 0·05 mg/kg per day for children <10 kg) intravenous push on days 2, 9, and 16. The primary outcome was investigator-assessed event-free survival. As prespecified by protocol, we analysed the primary endpoint 6 years after enrolment (cutoff date June 30, 2017). This trial is registered with ClinicalTrials.gov, number NCT00980460, and is now permanently closed to accrual. FINDINGS: Between May 18, 2010, and May 28, 2014, 51 patients in 32 centres in two countries were enrolled into the low-risk stratum of this trial, of whom 49 received c hemotherapy treatment after surgery and were evaluable for activity and safety. Median follow-up time for all evaluable patients was 42 months (IQR 36-62). 4-year event-free survival was 92% (95% CI 79-97) and 5-year event-free survival was 88% (72-95). Two (4%) of 49 patients had surgical complications (bile leaks). The most common grade 3-4 adverse events were febrile neutropenia in seven (14%) patients, decreased neutrophil count in three (6%) patients, infections in four (8%) patients, and diarrhoea in four (8%) patients. Ototoxicity occurred in one (2%) patient. One (2%) patient of the three who relapsed in this cohort died from disease. Two (4%) patients died in clinical remission after therapy discontinuation. One patient died of pneumonia and bacterial sepsis 1 year after therapy discontinuation and another patient died of unrelated causes 57 months after therapy completion. There were no treatment-related deaths. INTERPRETATION: Minimal postoperative chemotherapy with two cycles of cisplatin, fluorouracil, and vincristine can ensure disease control in patients with hepatoblastoma resected at diagnosis. Our results show that dose reduction of ototoxic agents is a safe, effective treatment for these children. FUNDING: National Institutes of Health.

A Rotavirus-Induced Mouse Model to Study Biliary Atresia and Neonatal Cholestasis.

Biliary atresia is a devastating neonatal cholangiopathy that affects both extra- and intrahepatic bile ducts progressing to fibrosis and end-stage liver disease by 2 years of age. Despite re-establishment of biliary drainage following a Kasai portoenterostomy (surgical procedure), many infants develop fibrosis requiring liver transplant. In the murine model of biliary atresia, rhesus rotavirus infection of newborn pups results in a cholangiopathy paralleling human biliary atresia and is used to study mechanistic aspects of the disease. The infected mice displayed histopathological signs similar to human biliary atresia, with bile duct obstruction, bile duct proliferation, and liver inflammation with fibrosis.

Transarterial radioembolization with yttrium-90 of unresectable primary hepatic malignancy in children.

BACKGROUND: Primary malignant liver tumors are rare, accounting for 1% to 2% of all childhood cancers. When chemotherapy fails, transarterial radioembolization with yttrium-90 (TARE-Y90) may offer an alternative therapy as a bridge to surgical resection or liver transplant or for palliation. METHODS: We conducted a retrospective review of 10 pediatric patients with histologically confirmed primary liver malignancy who received treatment with TARE-Y90. RESULTS: The median age at treatment was 5.5 years (range, 2-18 years). Median patient survival from initial diagnosis was 12.5 months (range, 10-28 months), and median patient survival after TARE-Y90 was 4 months (range, 2-20 months). Retreatment was well tolerated in three of 10 patients, with these patients demonstrating the longest survival times (range, 17-20 months). One patient was transplanted 6 weeks after TARE-Y90. By RECIST 1.1 criteria of all target lesions, eight of nine patients had stable disease, and one of nine had progressive disease. By mRECIST criteria (requiring postcontrast arterial phase imaging), two of seven patients had a partial response, four of seven had stable disease, and one of seven had progressive disease. CONCLUSION: TARE-Y90 of unresectable primary liver malignancy is both technically feasible and demonstrates an anticancer effect, and retreatment is well tolerated. TARE-Y90 could be considered as adjunctive therapy in pediatric patients with unresectable hepatic malignancies and could be used as a bridge to surgical resection or liver transplant. More research is required to determine the efficacy of this treatment in children and to define the clinical scenarios where benefit is likely to be optimized.