Metronomic Chemotherapy for Pediatric Refractory Solid Tumors: A Retrospective Single-Center Study.

Metronomic chemotherapy (MC) is based on chronic administration of chemotherapeutic agents at minimally toxic doses without prolonged drug-free breaks, that inhibits tumor angiogenesis and induces tumor dormancy. This study aimed to determine the efficacy of MC for pediatric refractory solid tumors. We retrospectively analyzed the data of pediatric patients with relapsed/refractory solid tumors who received treatment, including low-dose continuous administration of anticancer drugs, at our institute. Of the 18 patients, the disease statuses at the initiation of MC were complete remission (n=2), partial remission/stable disease (n=5), and progressive disease (n=11). The overall survival rate was 61% at 12 months and 34% at 24 months, and the progression-free survival rate was 21% at 12 and 24 months. Although only 5 of the 18 patients showed certain tumor regression or maintained remission, tumors that stabilized, maintained remission/stable disease, and showed certain advantages in terms of overall survival rate, even if limited to progressive disease. Approximately half of the patients demonstrated temporal tumor stabilization and improved survival time. Overall, previous reports and the present study support the conclusion that MC has the potential to play an important role in pediatric cancer treatment during the advanced stage.

Eculizumab treatment in paediatric patients diagnosed with aHUS after haematopoietic stem cell transplantation: a HSCT-TMA case series from Japanese aHUS post-marketing surveillance.

Haematopoietic stem-cell transplantation (HSCT)-associated thrombotic microangiopathy (HSCT-TMA) is a serious complication with high mortality. Accumulating evidence suggests that complement dysregulation is potentially involved in the development of HSCT-TMA. We retrospectively analysed the clinical characteristics and outcomes of thirteen paediatric patients who were diagnosed with atypical haemolytic uremic syndrome and treated with eculizumab to manage HSCT-TMA during post-marketing surveillance in Japan. The median time from HSCT to TMA was 31 days (Interquartile range, IQR;21-58) and the median doses of eculizumab was three (IQR;2-5). Seven patients (54%) were alive at the last follow-up while six died due to complications related to HSCT. Six of seven survivors initiated eculizumab after insufficient response to plasma therapy. Following eculizumab treatment, median platelet counts and LDH levels in all survivors significantly improved and renal function improved in 4/7 patients. All survivors possessed potential risk factors of complement overactivation. During the follow-up period after eculizumab discontinuation (median;111.5 days, IQR;95-555), no TMA recurrence was observed. In this analysis, eculizumab showed benefit in over half of this paediatric patient population. Ongoing clinical studies are expected to optimize the treatment regimen of terminal complement pathway inhibitor, and it may become a therapeutic option for paediatric HSCT-TMA in the future.

Case report: Hepatectomy with Rex bypass for a child with hepatoblastoma and portal vein thrombosis.

Pediatric liver tumors with portal vein obstruction are often candidates for liver transplantation. However, lifelong use of immunosuppressants and invasiveness to healthy donors in the case of living-donor liver transplantation is inevitable. Moreover, when lung metastasis is involved, the lung recurrence rate after liver transplantation is still high. Therefore, transplantation should be avoided as much as possible. In cases of tumors in the right lobe of the liver, complete resection of the portal vein trunk may be possible by creating a Rex bypass, but with the original method, end-to-side anastomosis to the umbilical portal vein is difficult in small children. We report a case of a 2-year-old girl with hepatoblastoma in whom a Rex shunt was created by end-to-end anastomosing the recanalized umbilical vein to the portal vein stump with interposing a vein graft, and the right lobe was successfully resected along with the tumor.

Common Blood Test Indices for Predicting Transient Abnormal Myelopoiesis-Related Mortality in Infants with Down Syndrome.

Transient abnormal myelopoiesis (TAM) can cause early death in children with Down syndrome, and liver failure is the most common cause of death. The aim of this single-center retrospective study was to identify a quantitative index for predicting TAM-related mortality at the time of diagnosis. Of the 462 children with Down syndrome admitted to our hospital from 1992 to 2021, we studied 12 infants with TAM-related death and 31 survivors who were diagnosed with TAM. In the death and survival groups, the median gestational ages were 34.9 and 37.1 weeks, respectively (p = 0.12). At diagnosis, the white blood cell (WBC) counts were 99.2 and 36.2 × 109/L (p = 0.011), the hemoglobin concentrations were 131 and 159 g/L (p = 0.009), and the serum albumin concentrations were 23 and 31 g/L (p < 0.001), respectively. The areas under the receiver operating characteristic curve for the abilities of the WBC count, hemoglobin, and serum albumin at diagnosis to predict survival were 0.75, 0.76, and 0.85, respectively. The serum albumin concentration threshold of 28 g/L at diagnosis had sensitivity of 0.79 and specificity of 0.82. Gestational age and serum albumin concentration were entered into a logistic regression model. The serum albumin concentration was an independent indicator of TAM-related death (adjusted odds ratio, 0.78; 95% confidence interval, 0.65-0.93; p = 0.005). In conclusion, a low serum albumin concentration at diagnosis may be a good predictor of TAM-related death.

Severe Hepatitis-associated Aplastic Anemia Following COVID-19 mRNA Vaccination.

We herein report a case of hepatitis-associated aplastic anemia (HAAA) that occurred after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. In this patient, progressive pancytopenia observed two months after acute hepatitis following the second dose of the SARS-CoV-2 vaccine indicated the development of HAAA. Although some reports have suggested that SARS-CoV-2 vaccination may be involved in the development of autoimmune diseases, no cases of HAAA developing after SARS-CoV-2 vaccination have been reported. SARS-CoV-2 vaccination in children has only started relatively recently, so the range of side effects in children has not yet been thoroughly described. Therefore, we need to strengthen surveillance for symptoms of children who are vaccinated.

Using the in vitro drug sensitivity test to identify candidate treatments for transient abnormal myelopoiesis.

Approximately 20% of patients with transient abnormal myelopoiesis (TAM) die due to hepatic or multiorgan failure. To identify potential new treatments for TAM, we performed in vitro drug sensitivity testing (DST) using the peripheral blood samples of eight patients with TAM. DST screened 41 agents for cytotoxic properties against TAM blasts. Compared with the reference samples of healthy subjects, TAM blasts were more sensitive to glucocorticoids, the mitogen-activated protein kinase kinase (MAP2K) inhibitor trametinib, and cytarabine. Our present results support the therapeutic potential of glucocorticoids and the role of the RAS/MAP2K signalling pathway in TAM pathogenesis.

Effect of extramedullary disease on allogeneic hematopoietic cell transplantation for pediatric acute myeloid leukemia: a nationwide retrospective study.

Children with acute myeloid leukemia (AML) commonly develop extramedullary disease (EMD), which comprises central nervous system (CNS) lesions and myeloid sarcoma (MS). In this retrospective analysis, we aimed to determine the effect of EMD on the outcomes of allogeneic hematopoietic cell transplantation (HCT) in 678 pediatric patients with de novo AML (median age, 7 years; range, 0.3-15 years) between 2006 and 2016. We compared the outcomes between patients with (EMD group, n = 158; CNS lesion, n = 47, CNS lesion + MS, n = 9, and MS, n = 102) and without EMD at diagnosis (non-EMD group, n = 520). Survivors were followed for a median of 4.5 years, and the 4-year overall survival (OS) rates were 60.6% and 56.4% in the EMD and non-EMD groups, respectively (P = 0.60). No significant differences in OS were observed with respect to the EMD site, except bone lesions, which were associated with poor OS after HCT in a non-remission status. A multivariate analysis revealed that EMD did not affect the outcomes of HCT. In conclusion, the study findings suggest that EMD should not be considered a poor prognostic factor in HCT for children with AML.

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

BACKGROUND: Preclinical observations suggested a synergistic effect of sorafenib (SFN) and irinotecan (CPT-11) in hepatoblastoma (HB). Thus, we conducted a feasibility study of fractionated CPT-11 combined with SFN to develop a new therapy against relapsed/refractory pediatric hepatic cancer (HC). PROCEDURE: The study was originally designed as a phase I, standard 3+3 dose-finding study to evaluate dose-limiting toxicities (DLTs) for the regimen and the optimal CPT-11 dose in combination with SFN against relapsed/refractory pediatric HC, including HB and hepatocellular carcinoma (HCC). The enrolled patients received SFN at 200 mg/m2 every 12 hours or 400 mg/m2 every 24 hours daily combined with CPT-11 at 20 mg/m2 /day on days 1 to 5 as an initial level 1 dose. RESULTS: Six patients with HB (n = 4) or HCC (n = 2) were enrolled and treated with CPT-11 dose level 1. The median age at enrollment was 8.7 (6.2-16.3) years. All patients received platinum-containing chemotherapy, and five or two patients received CPT-11 or SFN before enrollment, respectively. Regimen toxicities were evaluable in all patients. One of six patients experienced a grade 4 transaminase levels increase, which was defined as a DLT per protocol. Grade 3/4 neutropenia and a grade 3 transaminase level increase occurred in three patients and one patient, respectively. All patients reported grade 1/2 toxicities such as anemia, skin toxicity, gastrointestinal symptoms, and hypoalbuminemia. CONCLUSIONS: Although the study was terminated before determining the maximum-tolerated CPT-11 dose, SFN and CPT-11 at the level 1 dose were concluded to be tolerable in pediatric patients with HC.

Aurora B kinase as a therapeutic target in acute lymphoblastic leukemia.

PURPOSE: Acute lymphoblastic leukemia (ALL) is curable with standardized chemotherapy. However, the development of novel therapies is still required, especially for patients with relapsed or refractory disease. By utilizing an in vitro drug screening system, active molecular targeting agents against ALL were explored in this study. METHODS: By the in vitro drug sensitivity test, 81 agents with various actions were screened for their cytotoxicity in a panel of 22 ALL cell lines and ALL clinical samples. The drug effect score (DES) was calculated from the dose-response of each drug for comparison among drugs or samples. Normal peripheral blood mononuclear cells were also applied onto the drug screening to provide the reference control values. The drug combination effect was screened based on the Bliss independent model, and validated by the improved isobologram method. RESULTS: On sensitivity screening in a cell line panel, barasertib-HQPA which is an active metabolite of barasertib, an aurora B kinase inhibitor, alisertib, an aurora A kinase inhibitor, and YM155, a survivin inhibitor, were effective against the broadest range of ALL cells. The DES of barasertib-HQPA was significantly higher in ALL clinical samples compared to the reference value. There were significant correlations in DES between barasertib-HQPA and vincristine or docetaxel. In the drug combination assay, barasertib-HQPA and eribulin showed additive to synergistic effects. CONCLUSION: Aurora B kinase was identified to be an active therapeutic target in a broad range of ALL cells. Combination therapy of barasertib and a microtubule-targeting drug is of clinical interest.

Factors influencing platelet normalization of transient abnormal myelopoiesis.

BACKGROUND: Abnormal blood cell counts are characteristic of patients with Down syndrome and transient abnormal myelopoiesis (TAM). Although some patients with TAM experience prolonged anemia or thrombocytopenia, hematological factors predicting blood cell count recovery have not been reported yet. The aim of this study was to investigate the factors influencing platelet normalization in TAM. METHODS: A retrospective review of the medical records of 21 patients with TAM admitted to the neonatal intensive care unit at Kanagawa Children's Medical Center between January 2007 and October 2014 was undertaken. RESULTS: In the 16 of 21 patients (76%) experiencing transient thrombocytopenia, a large number of blasts at diagnosis was found to be significantly associated with late platelet recovery (R = 0.669, P < 0.05), and higher platelet counts at diagnosis were significantly associated with later recovery (R = 0.719, P < 0.01). Indeed, a strong positive correlation between blast and platelet counts at diagnosis was found (R = 0.730, P < 0.01). CONCLUSIONS: Our data suggest that high platelet counts at TAM diagnosis might reflect abnormal thrombocyte production from blasts. Thus, physicians should be aware of the possibility of prolonged thrombocytopenia in patients with TAM who exhibit a high platelet and/or blast count at diagnosis.

Hypofractionated radiotherapy in children with diffuse intrinsic pontine glioma.

BACKGROUND: Overall survival (OS) of patients with diffuse intrinsic pontine glioma (DIPG) is poor, with radiation therapy (RT) the only intervention that transiently delays tumor progression. Hypofractionated RT and re-irradiation at first progression have gained popularity in improving the quality of life of such patients. METHODS: We performed a retrospective review of children with DIPG treated at Kanagawa Children's Medical Center from 2000 to 2018. RESULTS: A total of 24 cases were reviewed. Median age at diagnosis was 6.3 years (1.6-14.0). Twenty patients received RT only once. Thirteen patients received conventionally fractionated RT, and seven patients received hypofractionated RT as up-front RT. Severe toxicities were not observed in patients who received hypofractionated RT. Median OS and time to progression were similar between conventionally fractionated and hypofractionated RT groups.(9.7 [95% confidence interval(CI): 7.1-11.2] versus 11.0[95% CI: 5.2-13.6] months, P = 0.60; 4.2[95% CI: 1.8-8.3] versus 7.1 [95% CI:4.5-8.7] months, P = 0.38). Four patients received re-irradiation at first progression and all patients showed transient neurological improvement and survival more than a year after diagnosis. A 4-year-old boy was re-irradiated 5-and-a-half months after the first re-irradiation; following transient neurological improvement. He survived a further 5 months. CONCLUSION: Hypofractionated RT for children with newly diagnosed DIPG is well tolerated and feasible from the viewpoint of reducing a patient's burden of treatment. Re-irradiation at first progression is suggested to be beneficial.

The Collagen Gel Droplet-embedded Culture Drug Sensitivity Test in Relapsed Hepatoblastoma.

There are few treatment options for patients with unresectable or refractory hepatoblastoma which has failed to respond to the standard treatment. The rarity of the disease and lack of experimental materials have hampered the development of new treatments. In this study, the collagen gel droplet-embedded culture drug sensitivity test was used to evaluate the effectiveness of the multikinase inhibitors sorafenib and sunitinib, and other drugs, in relapsed hepatoblastoma tumor tissues. Tumor samples from 6 patients with relapsed hepatoblastoma were tested for drug sensitivity by the collagen gel droplet-embedded culture drug sensitivity test; evaluable results were obtained from 5 of them. All samples were judged to be sensitive to sorafenib with a 50% growth inhibitory concentration (IC50) of 0.5 to 3.1 µg/mL. Sunitinib did not achieve IC50 in 2 of 3 samples within the tested concentration range based on clinically observed serum concentrations. In the drug combination assay using a hepatoblastoma cell line, sorafenib showed synergistic effects with SN-38, an active metabolite of irinotecan. Our results provide the basic science background warranting future clinical trials of a combination of sorafenib and irinotecan for relapsed or refractory hepatoblastoma.

Philadelphia chromosome-positive acute lymphoblastic leukemia and Down syndrome.

Children with Down syndrome (DS) are at high risk of developing acute lymphoblastic leukemia (ALL), but Philadelphia chromosome-positive (Ph+) ALL is rare in DS children. We report a case of Ph+ALL with DS complicated by chronic heart failure. Complete molecular remission was obtained after imatinib-combined chemotherapy, although infectious episodes during the neutropenic period worsened the heart condition. After two courses of intensification chemotherapy, the patient underwent reduced intensity stem cell transplantation from an HLA-identical sibling donor followed by post-transplant imatinib. The patient maintained molecular complete remission for >2 years. This case report is the first description of the safe and effective use of imatinib for DS-Ph+ALL. This case suggests the potential of molecular targeting therapy in DS-ALL, which is often complicated by congenital diseases, and the importance of treating DS-ALL while maintaining intensity and reducing treatment-related toxicity.

Clinical Courses of Two Pediatric Patients with Acute Megakaryoblastic Leukemia Harboring the CBFA2T3-GLIS2 Fusion Gene.

Acute megakaryoblastic leukemia (AMKL) in children without Down syndrome (DS) has an extremely poor outcome with 3-year survival of less than 40%, whereas AMKL in children with DS has an excellent survival rate. Recently, a novel recurrent translocation involving CBFA2T3 and GLIS2 was identified in about 30% of children with non-DS AMKL, and the fusion gene was reported as a strong poor prognostic factor in pediatric AMKL. We report the difficult clinical courses of pediatric patients with AMKL harboring the CBFA2T3-GLIS2 fusion gene.

The Potential and Limits of Hematopoietic Stem Cell Transplantation for the Treatment of Autosomal Dominant Hyper-IgE Syndrome.

PURPOSE: Autosomal dominant hyper-IgE syndrome (AD-HIES) is included among primary immunodeficiencies, and results from heterozygous mutations in the signal transduction and activator of transcription 3 (STAT3) gene. AD-HIES leads to impaired Th17 cell differentiation and IL-17 production, and is associated with increased susceptibility to bacteria and fungi. It was reported that several patients with AD-HIES were treated with hematopoietic stem cell transplantation (HSCT). The efficacy of HSCT in treating AD-HIES is variable. This study aims to evaluate the long-term clinical and immunological efficacy of HSCT for AD-HIES. METHODS: We have followed for more than 8 years two patients with AD-HIES who were treated with HSCT. Their ability of IL-17 production was evaluated by flow cytometry. RESULTS: Both patients indicated the normal ability of IL-17 production and their serum IgE levels decreased after HSCT. On the other hand, they suffered from pulmonary complications of AD-HIES such as pneumatoceles and bronchiectasis even after HSCT; however, the frequency of infections was decreased. CONCLUSIONS: Although the dysfunction of STAT3 in non-hematological tissues such as the lungs could not be corrected by HSCT, AD-HIES patients with risk factors for pulmonary complications may benefit from immunological correction by HSCT before severe pulmonary complications occur. Future studies should investigate risk factors for pulmonary complications in AD-HIES patients.

Hematopoietic stem cell transplantation for pediatric mature B-cell acute lymphoblastic leukemia with non-L3 morphology and MLL-AF9 gene fusion: three case reports and review of the literature.

Mature B-cell acute lymphoblastic leukemia (B-ALL) is typically associated with French-American-British (FAB)-L3 morphology and MYC gene rearrangement. However, rare cases of mature B-ALL with non-L3 morphology and MLL-AF9 fusion have been reported, and such cases are characterized by a rapid and aggressive clinical course. We here report three such cases of pediatric mature B-ALL in female patients respectively aged 15 months, 4 years, and 4 months. Bone marrow smears at diagnosis showed FAB-L1 morphology in all patients. Immunophenotypically, they were positive for cluster of differentiation (CD)10, CD19, CD20 (or CD22), Human Leukocyte Antigen-DR, and surface immunoglobulin λ. No evidence of MYC rearrangement was detected in any of the cases by fluorescent in situ hybridization (FISH) analysis. However, MLL rearrangement was detected by FISH, and MLL-AF9 fusion was confirmed by reverse transcriptase-polymerase chain reaction. All patients achieved complete remission after conventional chemotherapy and subsequently underwent hematopoietic stem cell transplantation as high-risk ALL; patient 3 for infantile ALL with MLL rearrangement and the others for ALL with MLL rearrangement and hyperleukocytosis (white blood cell count at diagnosis >50 × 10(9)/L). At the latest follow-up for each case (12-98 months post-transplantation), complete remission was maintained. Moreover, we discuss the clinical, genetic, and immunophenotypic features of this rare disease.