The impact of congenital heart disease on treatment and survival of patients with hepatoblastoma: A single-center experience.

BACKGROUND: Patients with hepatoblastoma (HB) have a higher risk of congenital heart defects (CHD). There is limited literature on the management and outcomes of these patients. The purpose of this study was to identify demographics and outcomes of these patients in a single tertiary referral center. METHODS: An Institutional Review Board (IRB)-approved retrospective chart review of patients with newly diagnosed HB from October 2004 to January 2021 was performed. CHD was defined as the presence of a septal defect, patent ductus arteriosus, pulmonary atresia, or bicuspid aortic valve. Chi-square and t-test were utilized for statistical analyses. RESULTS: Of the 151 patients diagnosed with HB during the study timeframe, 29 patients were found to have CHD. Five-year overall survival (OS) for non-CHD HB patients was 81.9% compared to 68.9% in the CHD cohort (p = .12). The 5-year OS for patients without surgically intervened CHD was 63.6% compared to 70.5% for those with surgically repaired CHD (p = .88). Pre-treatment extent of tumor IV was present more often in patients with HB and CHD who passed away (6/9, 66.7%) compared to those who survived (3/16,18.8%, p = .01). CONCLUSIONS: Patients with HB and CHD have similar survival compared to those without CHD. Our data support that patients with HB and CHD should be treated with curative intent including cardiac surgical intervention, medical oncology therapy, and oncological surgery for their HB.

A comprehensive analysis of neuroblastoma incidence, survival, and racial and ethnic disparities from 2001 to 2019.

BACKGROUND: We characterize the incidence and 5-year survival of children and adolescents with neuroblastoma stratified by demographic and clinical factors based on the comprehensive data from United States Cancer Statistics (USCS) and the National Program of Cancer Registries (NPCR). METHODS: We analyzed the incidence of neuroblastoma from USCS (2003-2019) and survival data from NPCR (2001-2018) for patients less than 20 years old. Incidence trends were calculated by average annual percent change (AAPC) using joinpoint regression. Differences in relative survival were estimated comparing non-overlapping confidence intervals (CI). RESULTS: We identified 11,543 primary neuroblastoma cases in USCS. Age-adjusted incidence was 8.3 per million persons [95% CI: 8.2, 8.5], with an AAPC of 0.4% [95% CI: -0.1, 0.9]. Five-year relative survival from the NPCR dataset (n = 10,676) was 79.7% [95% CI: 78.9, 80.5]. Patients aged less than 1 year had the highest 5-year relative survival (92.5%). Five-year relative survival was higher for non-Hispanic White patients (80.7%) or Hispanic patients (80.8%) compared to non-Hispanic Black patients (72.6%). CONCLUSION: Neuroblastoma incidence was stable during 2003-2019. Differences in relative survival exist by sex, age, race/ethnicity, and stage; patients who were male, older, non-Hispanic Black, or with distant disease had worse survival. Future studies could seek to assess the upstream factors driving disparities in survival, and evaluate interventions to address inequities and improve survival across all groups.

Renal function in abdominal neuroblastoma patients undergoing proton radiotherapy.

BACKGROUND: The purpose of this study is to analyze renal function outcomes in abdominal neuroblastoma patients undergoing proton therapy (PT). PROCEDURE: From 2011 to 2019, two single-institution Institutional Review Board-approved protocols prospectively enrolled neuroblastoma patients for data collection. To assess renal function, serum creatinine (Cr), blood urea nitrogen (BUN), and creatinine clearance (CrCl) before proton therapy (pre-PT) were compared with the values at last follow-up. RESULTS: A total of 30 children with abdominal neuroblastoma with median age 3.5 years (range, 0.9-9.1) at time of PT were included in this study. All patients underwent chemotherapy and resection of primary tumor prior to PT. Two patients required radical nephrectomy. Median follow-up after PT was 35 months. Mean dose to ipsilateral and contralateral kidney was 13.9 and 5.4 Gy, respectively. No patients developed hypertension or renal dysfunction during follow-up. There was no statistically significant change in serum BUN (p = .508), CrCl (p = .280), or eGFR (p = .246) between pre-PT and last follow-up. CONCLUSION: At a median follow-up of almost 3 years, renal toxicity was uncommon after PT. Longer follow-up and larger patient cohort data are needed to further assess impact of PT on renal function in this population.

Efficacy of post-induction therapy for high-risk neuroblastoma patients with end-induction residual disease.

BACKGROUND: High-risk neuroblastoma patients with end-induction residual disease commonly receive post-induction therapy in an effort to increase survival by improving the response before autologous stem cell transplantation (ASCT). The authors conducted a multicenter, retrospective study to investigate the efficacy of this approach. METHODS: Patients diagnosed between 2008 and 2018 without progressive disease with a partial response or worse at end-induction were stratified according to the post-induction treatment: 1) no additional therapy before ASCT (cohort 1), 2) post-induction "bridge" therapy before ASCT (cohort 2), and 3) post-induction therapy without ASCT (cohort 3). χ2 tests were used to compare patient characteristics. Three-year event-free survival (EFS) and overall survival (OS) were estimated by the Kaplan-Meier method and survival curves were compared by log-rank test. RESULTS: The study cohort consisted of 201 patients: cohort 1 (n = 123), cohort 2 (n = 51), and cohort 3 (n = 27). Although the end-induction response was better for cohort 1 than cohorts 2 and 3, the outcomes for cohorts 1 and 2 were not significantly different (P = .77 for EFS and P = .85 for OS). Inferior outcomes were observed for cohort 3 (P < .001 for EFS and P = .06 for OS). Among patients with end-induction stable metastatic disease, 3-year EFS was significantly improved for cohort 2 versus cohort 1 (P = .04). Cohort 3 patients with a complete response at metastatic sites after post-induction therapy had significantly better 3-year EFS than those with residual metastatic disease (P = .01). CONCLUSIONS: Prospective studies to confirm the benefits of bridge treatment and the prognostic significance of metastatic response observed in this study are warranted.

Incidence and 5-year survival of children and adolescents with hepatoblastoma in the United States.

OBJECTIVE: Hepatoblastoma (HB) is the most common pediatric primary malignant liver tumor, its incidence has been increasing worldwide, but recent changes in incidence and outcomes with high population coverage are not well characterized. METHODS: We defined the incidence of HB diagnosed during 2003-2017 from United States Cancer Statistics (USCS) database, and survival during 2001-2016 from the National Program of Cancer Registries (NPCR). Data were stratified by sex, race/ethnicity, age, tumor stage, county population, and diagnosis year. Incidence trends were assessed by calculating average annual percent change (AAPC) using Joinpoint regression. Differences in overall 5-year survival were estimated using Cox regression analysis. RESULTS: 2178 HB cases with an annual incidence rate of 1.76 per million persons were identified and incidence increased over time (AAPC = 2.2, 95% confidence interval [CI], 0.9-3.6). The 5-year relative survival was 76.9% (95% CI: 74.9-78.8) and the risk of death was lower for cases diagnosed after 2009 (hazard ratio [HR] = 0.77, 95% CI: 0.63-0.94), higher for ages 3-7 years and 8-19 years compared to 0-2 years (HR = 1.38, 95% CI: 1.10-1.76 and 1.83, 95% CI: 1.31-2.70, respectively), for distant compared to locoregional stage (HR = 2.77, 95% CI: 2.27-3.36), and for non-Hispanic Black compared to non-Hispanic White cases (HR = 1.39, 95% CI: 1.02-1.84). CONCLUSIONS: HB incidence increased, and survival improved over the study period. Disparities in survival exist by age, race or ethnicity, and stage. Further studies could identify factors affecting increases in HB cases, inform future interventions, and address disparities in outcomes.

Genomic analysis and preclinical xenograft model development identify potential therapeutic targets for MYOD1-mutant soft-tissue sarcoma of childhood.

The myogenic differentiation 1 gene (MYOD1) p.L122R somatic mutation was first discovered in a subset of clinically aggressive embryonal rhabdomyosarcomas and has since been described in both pediatric and adult spindle cell/sclerosing rhabdomyosarcomas. Relatively little is known about the clinical, molecular, and histopathological features of these tumors in children. In order to further characterize the genomic and clinical features of pediatric MYOD1-mutant sarcomas, we evaluated a cohort of soft-tissue sarcoma patients treated at Texas Children's Hospital. Tumor DNA was subjected to next-generation panel sequencing and/or Sanger sequencing of the MYOD1 hotspot mutation. The MYOD1 p.L122R mutation was identified in six tumors, with a variant allele fraction greater than 0.8 in three cases, suggestive of loss of heterozygosity. One sclerosing rhabdomyosarcoma lacking the MYOD1 hotspot mutation was observed to have a MYOD1 copy number gain, also with evidence of loss of heterozygosity. Cancer gene panel sequencing revealed potentially targetable alterations in six of seven (86%) patients with MYOD1 alterations, including four patients with an alteration in the PI3K-AKT pathway: two hotspot PIK3CA mutations and deletions in PTEN and TSC2. On histopathologic review, MYOD1-altered tumors exhibited spindle and/or round cells and varying degrees of hyaline sclerosis. At last follow-up, six patients had died of disease and the seventh progressed early and was subsequently lost to follow-up. Both pre- and post-therapy patient-derived xenograft models were generated from one patient's tumor. These models were confirmed to harbor the MYOD1 and PIK3CA mutations seen in the primary tumor and were shown to be sensitive to PI3K/mTOR inhibition in vitro and in vivo. In conclusion, this study adds to recent reports describing the clinicopathologic and genomic features of MYOD1-altered soft-tissue sarcomas in children, including dismal prognosis and potential molecular targets for therapy. The novel preclinical models developed will facilitate further biological and preclinical study of this rare and aggressive tumor. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The Best Pharmaceuticals for Children Act and Pediatric Research Equity Act reach the age of majority-An oncology perspective.

The scarcity of adequate pediatric drug labeling information has long been problematic in the pediatric population, which may place children at risk for adverse drug effects. The ontogeny of infants, children, and adolescents over the course of the first two decades of life pose complex pharmacokinetic, dosing, administration, effectiveness, and toxicity-related questions that require specific investigation. Here, we review the history that led to the passage of the Best Pharmaceuticals for Children Act (BPCA) and Pediatric Research Equity Act (PREA), and provide commentary on issues relevant to pediatric oncology now and in the future.

Peptide receptor radionuclide therapy for treatment of metastatic neuroendocrine tumors in children.

Neuroendocrine tumors (NETs) of the pancreas and midgut are extremely rare in children, and patients presenting with metastatic disease have poor survival. Given this rarity, treatments are extrapolated from guidelines for adults with NET. Recent clinical trials in adults with NETs have shown that the addition of peptide receptor radionuclide therapy (PRRT) with 177 Lu-DOTATATE resulted in a disease control rate of nearly 80%, with minimal side effects. We report our experience using 177 Lu-DOTATATE to treat two pediatric patients with metastatic NET.

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

BACKGROUND: Children with cancer diagnosis are overall at a higher risk of thrombosis. For a newly diagnosed blood clot, patients are commonly started on anticoagulants to prevent further extension and embolization of the clot. In the rare instance that a pediatric patient has a tumor thrombus, role of anticoagulation is less clear. PROCEDURE/METHODS: Patients under 21 years of age with a finding of tumor thrombus on imaging from 2010 to 2020 at Texas Children's Hospital were identified and their medical records were reviewed. RESULTS: A total of 50 patients were identified. Most thrombi were incidental findings at diagnosis; however, two patients presented with pulmonary embolism (PE). Inferior vena cava extension was noted in 36% of the patients, and 24% patients had an intracardiac tumor thrombus. Anticoagulation was initiated in 10 patients (20%). There was no difference in the rate of bland thrombus formation and/or embolization in patients who did or did not receive anticoagulation. However, three of the six patients with asymptomatic tumor thrombus who were started on anticoagulation had bleeding complications compared to only two patients in the no anticoagulation cohort (p < .05). CONCLUSION: Children with intravascular extension of solid tumors were not commonly started on anticoagulation at the time of diagnosis, irrespective of the extent of tumor thrombus. Furthermore, we observed a significant trend toward higher incidence of bleeding complications after initiation of anticoagulation for asymptomatic tumor thrombus. There is inadequate evidence at this time to support routine initiation of anticoagulation in pediatric patients with intravascular extension of solid tumors.

The Anti-Tumor Activity of the NEDD8 Inhibitor Pevonedistat in Neuroblastoma.

Pevonedistat is a neddylation inhibitor that blocks proteasomal degradation of cullin-RING ligase (CRL) proteins involved in the degradation of short-lived regulatory proteins, including those involved with cell-cycle regulation. We determined the sensitivity and mechanism of action of pevonedistat cytotoxicity in neuroblastoma. Pevonedistat cytotoxicity was assessed using cell viability assays and apoptosis. We examined mechanisms of action using flow cytometry, bromodeoxyuridine (BrDU) and immunoblots. Orthotopic mouse xenografts of human neuroblastoma were generated to assess in vivo anti-tumor activity. Neuroblastoma cell lines were very sensitive to pevonedistat (IC50 136-400 nM). The mechanism of pevonedistat cytotoxicity depended on p53 status. Neuroblastoma cells with mutant (p53MUT) or reduced levels of wild-type p53 (p53si-p53) underwent G2-M cell-cycle arrest with rereplication, whereas p53 wild-type (p53WT) cell lines underwent G0-G1 cell-cycle arrest and apoptosis. In orthotopic neuroblastoma models, pevonedistat decreased tumor weight independent of p53 status. Control mice had an average tumor weight of 1.6 mg + 0.8 mg versus 0.5 mg + 0.4 mg (p < 0.05) in mice treated with pevonedistat. The mechanism of action of pevonedistat in neuroblastoma cell lines in vitro appears p53 dependent. However, in vivo studies using mouse neuroblastoma orthotopic models showed a significant decrease in tumor weight following pevonedistat treatment independent of the p53 status. Novel chemotherapy agents, such as the NEDD8-activating enzyme (NAE) inhibitor pevonedistat, deserve further study in the treatment of neuroblastoma.

Do intravenous fluid substitutions influence methotrexate clearance? An unanticipated impact of an intravenous sodium bicarbonate drug shortage.

BACKGROUND: National drug shortages of essential medications for childhood cancer have increasingly posed a challenge in the treatment of patients. The efficacy of standardized supportive care practices to avoid treatment-related toxicities may be limited during these drug shortages. High-dose methotrexate (HDMTX) plays a critical role in modern treatment protocols for acute lymphoblastic leukemia and requires stringent supportive care measures to mitigate toxicity. As the result of a national intravenous (IV) sodium bicarbonate shortage, institutional standard HDMTX supportive care guidelines had to be modified. We describe the unanticipated consequences on HDMTX clearance. METHODS: We performed a retrospective chart review assessing the impact of alternative compositions of IV fluids on the mean 24-h methotrexate levels (Cpss ) of 25 patients receiving 76 total HDMTX infusions at Texas Children's Hospital Cancer Center from March to October 2017. During the sodium bicarbonate drug shortage, all patients received IV hydration consisting of either dextrose 5%, 0.45% normal saline (D5 ½ NS-Group A) or dextrose 5%, 0.2% normal saline (D5 » NS-Group B). RESULTS: Patients receiving a higher total sodium dose demonstrated significantly lower Cpss (25.36 ± 16.6 µMol) compared to patients receiving less sodium (53.9 ± 37.9 µMol; P < .001). CONCLUSIONS: Our report shows that in the setting of IV sodium bicarbonate shortage, the composition of hydration IV fluids may affect methotrexate clearance. Patient who received a higher sodium load had a lower 24-h methotrexate level. This demonstrates the potential for unanticipated outcomes resulting from national drug shortages.

Risk factors associated with delayed methotrexate clearance and increased toxicity in pediatric patients with osteosarcoma.

High-dose methotrexate (HD-MTX; 12 g/m2 ) is part of standard therapy for pediatric osteosarcoma (OS). Risk factors associated with MTX toxicity in children with OS are not well defined. We investigated the association between peak MTX levels (four-hour) and delayed MTX clearance or treatment toxicity. Information was retrieved from electronic medical records of 33 OS patients treated with HD-MTX at Texas Children's Hospital from 2008 to 2015. We found that the four-hour MTX level did not contribute to toxicity or delayed MTX clearance. We demonstrated that certain demographic characteristics are associated with delayed clearance and increased toxicity.

Is high-risk neuroblastoma induction chemotherapy possible without G-CSF? A pilot study of safety and treatment delays in the absence of primary prophylactic hematopoietic growth factors.

BACKGROUND/OBJECTIVES: Standard supportive care during induction therapy for high-risk neuroblastoma (HR-NBL) includes primary prophylactic granulocyte colony-stimulating factor (G-CSF) aimed at limiting duration of neutropenia, reducing infection risk, and minimizing treatment delays. Preclinical models suggest that G-CSF promotes maintenance of neuroblastoma cancer stem cells and may reduce the efficacy of chemotherapy. This study's objective was to determine the safety and feasibility of administering induction chemotherapy without routine use of prophylactic G-CSF. DESIGN/METHODS: Children with newly diagnosed HR-NBL received six-cycle induction chemotherapy regimen without prophylactic G-CSF in four cycles. G-CSF was administered for stem cell mobilization after cycle 3 and granulocyte-monocyte colony-stimulating factor after cycle 5 prior to surgical resection of primary disease. The primary outcome measure was the incidence of grade 3 or higher infection. We hypothesized that the per patient infection rate would be comparable to our institutional baseline rate of 58% in patients with HR-NBL receiving induction chemotherapy with prophylactic growth factor support. The trial used an A'Hern single-stage design. RESULTS: Twelve patients with HR-NBL received 58 cycles of chemotherapy on study. Three patients completed the entire six-cycle regimen with no infections. Nine patients experienced grade 3 infections (bacteremia four, urinary tract infection two, skin/soft tissue infection three). No patients experienced grade 4 infections or required intensive care treatment for infection. CONCLUSION: A greater than expected number of serious bacterial infections were observed during administration of induction chemotherapy for HR-NBL without primary prophylactic G-CSF. These results support continued prophylactic administration growth factor during induction chemotherapy.

Factors Impacting Time to Engraftment in Patients With High-risk Neuroblastoma Following Autologous Stem Cell Transplant.

BACKGROUND: Despite advances in supportive measures, myeloablative chemotherapy with stem cell rescue remains limited by toxicity and treatment-related mortality. The purpose of this study was to identify factors influencing the rate of hematopoietic recovery following autologous stem cell transplant in high-risk neuroblastoma. PROCEDURE: We retrospectively studied 54 patients with high-risk neuroblastoma who received a single autologous stem cell transplant between 2006 and 2016. Race, sex, conditioning regimen, chemotherapy delays and bone marrow involvement were analyzed using Kaplan-Meier Log-Rank test while the amount of cells infused, age, and length of hospital stay were analyzed using univariate Cox Proportional Hazards Regression. RESULTS: The conditioning regimen administered was significant (P=0.016) for time to engraftment of neutrophils, with busulfan/melphalan (Bu/Mel) at 16.6 days, and carboplatin/etoposide/melphalan at 12.1 days. A delay of chemotherapy during induction (n=24) was significant (P<0.001) for time to platelet engraftment of >75,000/µL. Female patients had a longer time to engraftment (P=0.029). CONCLUSION: Patients receiving Bu/Mel as a conditioning regimen, patients who had a delay in induction chemotherapy and patients of female sex were found to be significant for delayed engraftment of neutrophils, platelets, and hemoglobin, respectively, in patients with high-risk neuroblastoma undergoing autologous stem cell transplant. Knowing these factors may lead to new expectations and possible interventions to decrease the morbidity and mortality of treatment and recovery.

Blood product administration during high risk neuroblastoma therapy.

The increasing intensity of high-risk neuroblastoma (HR NB) treatment over the last decades has resulted in improved survival at the expense of prolonging therapy and exposure to additional potentially toxic agents. Anemia and thrombocytopenia requiring transfusion are common during therapy for HR NB. Risks of cumulative red blood cell and platelet transfusions are incompletely defined in pediatric oncology patients, however, risks of transfusional iron overload are well described in other populations. This study aimed to determine the number of packed red blood cell (pRBC) and platelet transfusions throughout treatment for HR NB and how these numbers have changed with modern therapy. We performed a retrospective review of 92 patients with HR NB from June 2002 until September 2017. Patients received a median of 20 pRBC and 32 platelet transfusions. Our results demonstrated large numbers of transfusions with significantly increased blood product exposures among patients who received intensified therapy, either with additional induction chemotherapy, tandem autologous stem cell transplants, or dinutuximab plus cytokines with isotretinoin. Similar volumes of pRBC transfusions have been associated with iron overload in other populations and warrant further discussion of guidelines for long-term follow up of HR NB patients.

Acute Megakaryoblastic Leukemia With Diffuse Periosteal Reaction of Bilateral Lower Extremities.

We report the case of a 3-year-old girl diagnosed with acute megakaryoblastic leukemia, who presented after >1 year of bilateral leg pain. At times the pain was severe enough to prevent ambulation, prompting visits to her primary care provider. However, it was not until acute respiratory failure occurred with subsequent hospitalization in the pediatric intensive care unit that severe anemia and thrombocytopenia were discovered and the diagnosis of acute myeloid leukemia was made. Bilateral lower extremity swelling was noted on admission and radiographs showed diffusely abnormal appearance of the long bones of her lower extremities with periosteal reaction and echogenic debris in the subperiosteal space, thought to represent leukemic cells. This case highlights the importance of recognizing atypical signs and symptoms of myelodysplastic syndrome progressing to acute leukemia in the context of abnormal bone pain and radiographic changes.

Immunoglobulin prophylaxis in pediatric hematopoietic stem cell transplant.

BACKGROUND: After allogeneic hematopoietic stem cell transplantation (HSCT), patients have an increased susceptibility to infections, thought to be due in part to hypogammaglobulinemia. Thus, prophylactic administration of intravenous immunoglobulins (IVIG) has been administered to patients after HSCT as standard of care. This study compares the viral infection rate between dosing IVIG by IgG levels versus by routine monthly administration in pediatric patients after HSCT. PROCEDURE: In this retrospective chart review, we abstracted from electronic medical records data on pediatric patients undergoing HSCT from 2010 to 2012 for 6 months post-HSCT. We compared rates of infection between patients treated with routine IVIG prophylaxis and patients given IVIG prophylaxis based on IgG tough levels (IgG levels were checked every 2 weeks). RESULTS: Data were available and reviewed for 50 patients dosed with IVIG every 28 days (Group 1) and 100 patients dosed with IVIG based on IgG level > 400 mg/dl (Group 2). There was no significant difference in age (P = 0.98) or sex (P = 0.42), reason for HSCT, alemtuzumab use (P = 0.602), or reduced intensity conditioning (P = 1.00). Significantly more haploidentical donors were in Group 1 (P = 0.04), otherwise there was no significant difference in donor type between groups. Significantly less acute graft versus host disease occurred (P = <0.001) in Group 2 (P = <0.001). PCR documented viral infections were not significantly different (P = 0.412) (Table 1). Group 2 patients received significantly less IVIG (P < 0.001). CONCLUSION: Dosing IVIG to maintain an IgG level > 400 mg/dl is a cost-effective and safe way to prevent viral infections in pediatric patients undergoing HSCT.

Intravesicular cidofovir for BK hemorrhagic cystitis in pediatric patients after hematopoietic stem cell transplant.

BK virus hemorrhagic cystitis is a complication of HCST. Response to IV cidofovir is unpredictable, and treatment carries risk of toxicity. We report the largest series of pediatric patients with BKHC after HSCT successfully treated with intravesicular cidofovir. There was no significant decrease in urine or plasma BK PCR. There was significant decrease in pain score on days 3 and 7, with associated decrease in morphine use. No patients experienced toxicities associated with IV cidofovir. Intravesicular cidofovir appears to be safe and effective for symptomatic treatment of BKHC in pediatric patients after HSCT.

Using a Bedside Algorithm to Individually Dose High-dose Methotrexate for Patients at Risk for Toxicity.

We developed a bedside algorithm for individually adjusting the high-dose methotrexate (HDMTX) dose (5 g/m) given to patients with acute lymphoblastic leukemia at high risk for methotrexate toxicity. Data were reviewed for 8 patients receiving 21 cycles of HDMTX as per our algorithm. Eleven cycles began with 5 g/m, 10 cycles began with a preinfusion 20% to 25% dose reduction. Neither mean MTX AUC (2320.5±179.1 vs. 2080.4±161.7 µmol×h/L), mean Cpss (64.3±7.9 vs. 60.8±6.1 µM), nor toxicities were statistically different between groups. Our algorithm allowed the safe administration of HDMTX to patients at risk of MTX toxicities and obviated the need for preinfusion dose reduction.