Intraventricular methotrexate as part of primary therapy for children with infant and/or metastatic medulloblastoma: Feasibility, acute toxicity and evidence for efficacy

What Have We Learnt from the Recent Multimodal Managements of Young Patients with ATRT?

Atypical teratoid rhabdoid tumors are rare embryonal tumors of the nervous system mainly seen in very young children with aggressive behavior and dismal prognosis when treated with conventional chemotherapy only. More recent multimodal strategies combining, variably, high dose chemotherapy, radiotherapy and or intrathecal chemotherapy have led to some stride in survival. We present the results of the most recent clinical trials and registry data for patients treated with these multimodal approaches with survival ranging from 37.1% to 88.9%. We review the current consensus of the molecular characterization of these tumors into 3 subgroups (ATRT-TYR, ATRT-SHH and ATRT-MYC) and discuss the potential clinical impact of molecular subgrouping on survival. We explore other therapeutic tools including intrathecal chemotherapy and maintenance and possible new targeted agents for patients failing multimodal strategies.

Treatment of Medulloblastoma in the Adolescent and Young Adult Population: A Systematic Review

Medulloblastoma is the most frequent high-grade tumor of the central nervous system in children but accounts for less than 1% of these tumors in adults. Adolescent and young adult (AYA) patients are between both age groups, and different approaches are used to treat medulloblastoma in this population. We performed a systematic review of studies published between 2007 and 2023 that reported treatment approaches and survival data of AYA patients with medulloblastoma, defined as 15 to 39 years of age at diagnosis. Due to the heterogeneity of data, a meta-analysis was not possible. Except for the omission of chemotherapy after radiotherapy in a few adult studies, the treatment backbone is very similar between studies starting enrolment during childhood and older adolescence or adulthood. Despite indications for a higher rate of early treatment termination due to toxicity in adults, survival data remain comparable between studies starting enrolment earlier or later in life. However, molecular subtyping was missing in most studies, so the survival data must be interpreted cautiously. Nevertheless, pediatric-inspired strategies in the AYA population are feasible, but individual dose adjustments may be necessary during treatment and should be considered upfront. Collaborative studies investigating the best treatment approach for medulloblastoma in the AYA population are needed in the future.

Metabolic profiling of patient-derived organoids reveals nucleotide synthesis as a metabolic vulnerability in malignant rhabdoid tumors

Malignant rhabdoid tumor (MRT) is one of the most aggressive childhood cancers for which no effective treatment options are available. Reprogramming of cellular metabolism is an important hallmark of cancer, with various metabolism-based drugs being approved as a cancer treatment. In this study, we use patient-derived tumor organoids (tumoroids) to map the metabolic landscape of several pediatric cancers. Combining gene expression analyses and metabolite profiling using mass spectrometry, we find nucleotide biosynthesis to be a particular vulnerability of MRT. Treatment of MRT tumoroids with de novo nucleotide synthesis inhibitors methotrexate (MTX) and BAY-2402234 lowers nucleotide levels in MRT tumoroids and induces apoptosis. Lastly, we demonstrate in vivo efficacy of MTX in MRT patient-derived xenograft (PDX) mouse models. Our study reveals nucleotide biosynthesis as an MRT-specific metabolic vulnerability, which can ultimately lead to better treatment options for children suffering from this lethal pediatric malignancy.

Intraventricular SHH inhibition proves efficient in SHH medulloblastoma mouse model and prevents systemic side effects

BACKGROUND

Medulloblastoma (MB) is the most common malignant brain tumor in children and requires intensive multimodal therapy. Long-term survival is still dissatisfying and, most importantly, survivors frequently suffer from severe treatment-associated morbidities. The sonic hedgehog pathway (SHH) in SHH MB provides a promising target for specific therapeutic agents. The small molecule Vismodegib allosterically inhibits SMO, the main upstream activator of SHH. Vismodegib has proven effective in the treatment of MB in mice and in clinical studies. However, due to irreversible premature epiphyseal growth plate fusions after systemic application to infant mice and children, its implementation to pediatric patients has been limited. Intraventricular Vismodegib application might provide a promising novel treatment strategy for pediatric medulloblastoma patients.

METHODS

Infant medulloblastoma-bearing Math1-cre::Ptch1Fl/Fl mice were treated with intraventricular Vismodegib in order to evaluate efficacy on tumor growth and systemic side effects.

RESULTS

We show that intraventricular Vismodegib treatment of Math1-cre::Ptch1Fl/Fl mice leads to complete or partial tumor remission only 2 days after completed treatment. Intraventricular treatment also significantly improved symptom-free survival in a dose-dependent manner. At the same time, intraventricular application prevented systemic side effects in the form of anatomical or histological bone deformities.

CONCLUSIONS

We conclude that intraventricular application of a SHH pathway inhibitor combines the advantages of a specific treatment agent with precise drug delivery and might evolve as a promising new way of targeted treatment for SHH MB patients.

PANCDR: precise medicine prediction using an adversarial network for cancer drug response

Pharmacogenomics aims to provide personalized therapy to patients based on their genetic variability. However, accurate prediction of cancer drug response (CDR) is challenging due to genetic heterogeneity. Since clinical data are limited, most studies predicting drug response use preclinical data to train models. However, such models might not be generalizable to external clinical data due to differences between the preclinical and clinical datasets. In this study, a Precision Medicine Prediction using an Adversarial Network for Cancer Drug Response (PANCDR) model is proposed. PANCDR consists of two sub-models, an adversarial model and a CDR prediction model. The adversarial model reduces the gap between the preclinical and clinical datasets, while the CDR prediction model extracts features and predicts responses. PANCDR was trained using both preclinical data and unlabeled clinical data. Subsequently, it was tested on external clinical data, including The Cancer Genome Atlas and brain tumor patients. PANCDR outperformed other machine learning models in predicting external test data. Our results demonstrate the robustness of PANCDR and its potential in precision medicine by recommending patient-specific drug candidates. The PANCDR codes and data are available at https://github.com/DMCB-GIST/PANCDR.

Efficacy of intrathecal methotrexate in children with high-risk medulloblastoma over three years: a retrospective study from a single center

PURPOSE

Chemotherapy is commonly used for treatment in children over three years old with high-risk medulloblastoma(MB). However, little is currently known about the therapeutic benefits and side effects of intrathecal methotrexate(MTX), warranting further research.

METHODS

In this retrospective study, patients who received intrathecal MTX during chemotherapy were included in the MTX group (n = 32), and patients that only underwent cerebrospinal fluid (CSF) cytology analysis were assigned to the control group (n = 14).

RESULTS

In the MTX group, 27(84.38%) patients had metastatic disease, 3(9.38%) had diffuse anaplasia, and 3(9.38%) had residual disease greater than 1.5 cm2. Molecular subgroup classification was available for 28(87.5%) patients. In the control group, 8(57.14%) patients had metastatic disease, 3(27.27%) had diffuse anaplasia, and 6(42.86%) had residual disease greater than 1.5 cm2. Molecular subgroup classification was available for 6(42.86%) patients. The 5-year progression-free survival was 70.99% and the 5-year overall survival was 72.99% for the MTX group, and the corresponding values were 41.67% and 50% for the control group, respectively. 6 (18.75%) patients in the MTX group with group 4 disease developed MTX-related acute leukoencephalopathy and one of them died.

CONCLUSIONS

Our findings support the addition of intrathecal MTX during chemotherapy as the optimal management for children with group 3 and SHH high-risk MB. However, it is not recommended for group 4 MB patients, especially in resource-limited regions.

TRIAL REGISTRATION NUMBER

Retrospective registered No.(2020 - 117).

CNS penetration of methotrexate and its metabolite 7-hydroxymethotrexate in mice bearing orthotopic Group 3 medulloblastoma tumors and model-based simulations for children

The brain penetration of methotrexate (MTX) and its metabolite 7-hydroxymethotrexate (7OHMTX) was characterized in non-tumor bearing mice and mice bearing orthotopic Group 3 medulloblastoma. Plasma pharmacokinetic studies and cerebral and ventricular microdialysis studies were performed in animals dosed with 200 or 1000 mg/kg MTX by IV bolus. Plasma, brain/tumor extracellular fluid (ECF) and lateral ventricle cerebrospinal fluid (CSF) MTX and 7OHMTX concentration-time data were analyzed by validated LC-MS/MS methods and modeled using a population-based pharmacokinetic approach and a hybrid physiologically-based model structure for the brain compartments. Brain penetration was similar for MTX and 7OHMTX and was not significantly different between non-tumor and tumor bearing mice. Overall, mean (±SD) model-derived unbound plasma to ECF partition coefficient K_p,uu were 0.17 (0.09) and 0.17 (0.12) for MTX and 7OHMTX, respectively. Unbound plasma to CSF K_p,uu were 0.11 (0.06) and 0.18 (0.09) for MTX and 7OHMTX, respectively. The plasma and brain model were scaled to children using allometric principles and pediatric physiological parameters. Model-based simulations were adequately overlaid with digitized plasma and CSF lumbar data collected in children receiving different MTX systemic infusions. This model can be used to further explore and optimize methotrexate dosing regimens in children with brain tumors.

The peculiar challenge of bringing CAR-T cells into the brain: Perspectives in the clinical application to the treatment of pediatric central nervous system tumors

Childhood malignant brain tumors remain a significant cause of death in the pediatric population, despite the use of aggressive multimodal treatments. New therapeutic approaches are urgently needed for these patients in order to improve prognosis, while reducing side effects and long-term sequelae of the treatment. Immunotherapy is an attractive option and, in particular, the use of gene-modified T cells expressing a chimeric antigen receptor (CAR-T cells) represents a promising approach. Major hurdles in the clinical application of this approach in neuro-oncology, however, exist. The peculiar location of brain tumors leads to both a difficulty of access to the tumor mass, shielded by the blood-brain barrier (BBB), and to an increased risk of potentially life-threatening neurotoxicity, due to the primary location of the disease in the CNS and the low intracranial volume reserve. There are no unequivocal data on the best way of CAR-T cell administration. Multiple trials exploring the use of CD19 CAR-T cells for hematologic malignancies proved that genetically engineered T cells can cross the BBB, suggesting that systemically administered CAR-T cell can be used in the neuro-oncology setting. Intrathecal and intra-tumoral delivery can be easily managed with local implantable devices, suitable also for a more precise neuro-monitoring. The identification of specific approaches of neuro-monitoring is of utmost importance in these patients. In the present review, we highlight the most relevant potential challenges associated with the application of CAR-T cell therapy in pediatric brain cancers, focusing on the evaluation of the best route of delivery, the peculiar risk of neurotoxicity and the related neuro-monitoring.

Medulloblastoma in the Modern Era: Review of Contemporary Trials, Molecular Advances, and Updates in Management

Critical discoveries over the past two decades have transformed our understanding of medulloblastoma from a single entity into a clinically and biologically heterogeneous disease composed of at least four molecularly distinct subgroups with prognostically and therapeutically relevant genomic signatures. Contemporary clinical trials also have provided valuable insight guiding appropriate treatment strategies. Despite therapeutic and biological advances, medulloblastoma patients across the age spectrum experience tumor- and treatment-related morbidity and mortality. Using an updated risk stratification approach integrating both clinical and molecular features, ongoing research seeks to (1) cautiously reduce therapy and mitigate toxicity in low-average risk patients, and (2) thoughtfully intensify treatment with incorporation of novel, biologically guided agents for patients with high-risk disease. Herein, we review important historical and contemporary studies, discuss management updates, and summarize current knowledge of the biological landscape across unique pediatric, infant, young adult, and relapsed medulloblastoma populations.

Tandem autologous hematopoietic stem cell transplantation for embryonal brain tumors in infants and very young children

Withdrawal of radiotherapy in patients with brain tumors under four years decreases chance for cure. AutoHSCT in a series of pilot studies demonstrated a potential to improve outcomes in these patients. The study included 50 patients with median age of 39 months (7-53). Medulloblastoma (n = 28, 56%), ETMR (n = 9, 18%) and other histological types (n = 13, 26%) were most commonly diagnosed. Forty two patients (84%) received tandem autoHSCT by HIT-MED protocol, and single autoHSCT was performed in eight children (16%). Adjuvant radiotherapy was administered in 25 (50%) children and treatment of relapse included radiotherapy in 6 (12%). Median follow-up was 39.6 months (6-121). Long-term CIR was 37%, and TRM - 6%. Five-year OS was 71% in medulloblastoma, 37% in ETMR and in other tumors - 51% (p = 0.07). Irradiation-free OS at 5 years for children with medulloblastoma was 24%. For the whole cohort of CNS tumors, independently of histology, OS and PFS at five years were 60% and 46%, respectively Young children with medulloblastoma, following tandem autoHSCT, demonstrate OS comparable to older children. Patients with other histological types demonstrate suboptimal long-term survival rates after autoHSCT and one should assess whether these patients benefit from autoHSCT.

Clinical and molecular characterization of isolated M1 disease in pediatric medulloblastoma: experience from the German HIT-MED studies

Purpose

To evaluate the clinical impact of isolated spread of medulloblastoma cells into cerebrospinal fluid without additional macroscopic metastases (M1-only).

Methods

The HIT-MED database was searched for pediatric patients with M1-only medulloblastoma diagnosed from 2000 to 2019. Corresponding clinical and molecular data was evaluated. Treatment was stratified by age and changed over time for older patients.

Results

70 patients with centrally reviewed M1-only disease were identified. Clinical data was available for all and molecular data for 45/70 cases. 91% were non-WNT/non-SHH medulloblastoma (Grp3/4).

5-year PFS for 52 patients ≥ 4 years was 59.4 (± 7.1) %, receiving either upfront craniospinal irradiation (CSI) or SKK-sandwich chemotherapy (CT). Outcomes did not differ between these strategies (5-year PFS: CSI 61.7 ± 9.9%, SKK-CT 56.7 ± 6.1%). For patients < 4 years (n = 18), 5-year PFS was 50.0 (± 13.2) %. M1-persistence occurred exclusively using postoperative CT and was a strong negative predictive factor (p_PFS/OS < 0.01).

Patients with additional clinical or molecular high-risk (HR) characteristics had worse outcomes (5-year PFS 42.7 ± 10.6% vs. 64.0 ± 7.0%, p = 0.03). In n = 22 patients ≥ 4 years with full molecular information and without additional HR characteristics, risk classification by molecular subtyping had an effect on 5-year PFS (HR 16.7 ± 15.2%, SR 77.8 ± 13.9%; p = 0.01).

Conclusions

Our results confirm that M1-only is a high-risk condition, and further underline the importance of CSF staging. Specific risk stratification of affected patients needs attention in future discussions for trials and treatment recommendations. Future patients without contraindications may benefit from upfront CSI by sparing risks related to higher cumulative CT applied in sandwich regimen.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11060-021-03913-5.

Epidemiological characteristics and survival outcomes of children with medulloblastoma treated at the National Cancer Institute (INCA) in Rio de Janeiro, Brazil

BACKGROUND

Medulloblastoma (MB),the most common malignant brain tumor of childhood has survival outcomes exceeding 80% for standard-risk and 60% for high-risk patients in high-income countries (HICs). These results have not been replicated in low- and middle-income countries (LMICs), where 80% of children with cancer live.

METHODS

This is a retrospective review of 114 children aged 3-18 years diagnosed with MB from 1997 to 2016 at National Cancer Institute (INCA). Sociodemographic, clinical, and treatment data were extracted from the medical records and summarized descriptively. Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan-Meier method.

RESULTS

The male-to-female ratio was 1.32 and the median age at diagnosis was 8.2 years. Headache (83%) and nausea/vomiting (78%) were the most common presenting symptoms. Five-year OS was 59.1% and PFS was 58.4%. The OS for standard-risk and high-risk patients was 69% and 53%, respectively. The median time to diagnosis interval was 50.5 days and the median time from surgery to radiation therapy initiation was 50.4 days. Patients who lived >40 km from INCA fared better (OS = 68.2% vs. 51.1%, p = .032). Almost 20% of families lived below the Brazilian minimum wage. Forty-five patients (35%) had metastatic disease at admission. Gross total resection was achieved in 57% of the patitents.

CONCLUSIONS

Although there are considerable barriers to deliver effective MB treatment in countries like Brazil, the OS seen in the present study demonstrates that good outcomes are not only feasible but can and should be increased with appropriate interventions.

Relapsed Medulloblastoma in Pre-Irradiated Patients: Current Practice for Diagnostics and Treatment

Relapsed medulloblastoma (rMB) accounts for a considerable, and disproportionate amount of childhood cancer deaths. Recent advances have gone someway to characterising disease biology at relapse including second malignancies that often cannot be distinguished from relapse on imaging alone. Furthermore, there are now multiple international early-phase trials exploring drug-target matches across a range of high-risk/relapsed paediatric tumours. Despite these advances, treatment at relapse in pre-irradiated patients is typically non-curative and focuses on providing life-prolonging and symptom-modifying care that is tailored to the needs and wishes of the individual and their family. Here, we describe the current understanding of prognostic factors at disease relapse such as principal molecular group, adverse molecular biology, and timing of relapse. We provide an overview of the clinical diagnostic process including signs and symptoms, staging investigations, and molecular pathology, followed by a summary of treatment modalities and considerations. Finally, we summarise future directions to progress understanding of treatment resistance and the biological mechanisms underpinning early therapy-refractory and relapsed disease. These initiatives include development of comprehensive and collaborative molecular profiling approaches at relapse, liquid biopsies such as cerebrospinal fluid (CSF) as a biomarker of minimal residual disease (MRD), modelling strategies, and the use of primary tumour material for real-time drug screening approaches.

Signaling pathway deregulation and molecular alterations across pediatric medulloblastomas

Medulloblastomas (MBs) account for 15% of brain tumors in children under the age of 15. To date, the overall 5-year survival rate for all children is only around 60%. Recent advances in cancer genomics have led to a fundamental change in medulloblastoma classification and is evolving along with the genomic discoveries, allowing to regularly reclassify this disease. The previous molecular classification defined 4 groups (WNT-activated MB, SHH-activated MB and the groups 3 and 4 characterized partially by NMYC and MYC driven MBs). This stratification moved forward recently to better define these groups and their correlation to outcome. This new stratification into 7 novel subgroups was helpful to lay foundations and complementary data on the understanding regarding molecular pathways and gene mutations underlying medulloblastoma biology. This review was aimed at answering the recent key questions on MB genomics and go further in the relevance of those genes in MB development as well as in their targeted therapies.

Radiation therapy for infants with cancer

The clinical outcomes for infants with malignant tumors are often worse than older children due to a combination of more biologically aggressive disease in some cases, and increased toxicity-or deintensification of therapies due to concern for toxicity-in others. Especially in infants and very young children, finding the appropriate balance between maximizing treatment efficacy while minimizing toxicity-in particular late side effects-is crucial. We review here the management of malignant tumors in infants and very young children, focusing on central nervous system (CNS) malignancies and rhabdomyosarcoma.

Bridging the treatment gap in infant medulloblastoma: molecularly informed outcomes of a globally feasible regimen

BACKGROUND

Infant medulloblastoma represents an enormous challenge in neuro-oncology, due to their simultaneous high-risk of recurrence and high risk of severe neurodevelopmental sequelae with craniospinal irradiation. Currently infant medulloblastoma are treated with intensified protocols, either comprising intraventricular methotrexate or autologous transplant, both of which carry significant morbidity and are not feasible in the majority of the world. We sought to evaluate the molecular predictors of outcome in a cohort of infants homogeneously treated with induction chemotherapy, focal radiation and maintenance chemotherapy.

METHODS

In a retrospective analysis, 29 young children treated with a craniospinal irradiation sparing strategy from Hospital Garrahan in Buenos Aires were profiled using Illumina HumanMethylationEPIC arrays, and correlated with survival.

RESULTS

Twenty-nine children (range, 0.3-4.6 y) were identified, comprising 17 sonic hedgehog (SHH), 10 Group 3/4, and 2 non-medulloblastomas. Progression-free survival (PFS) across the entire cohort was 0.704 (95% CI: 0.551-0.899). Analysis by t-distributed stochastic neighbor embedding revealed 3 predominant groups, SHHβ, SHHγ, and Group 3. Survival by subtype was highly prognostic with SHHγ having an excellent 5-year PFS of 100% (95% CI: 0.633-1) and SHHβ having a PFS of 0.56 (95% CI: 0.42-1). Group 3 had a PFS of 0.50 (95% CI: 0.25-1). Assessment of neurocognitive outcome was performed in 11 patients; the majority of survivors fell within the low average to mild intellectual disability, with a median IQ of 73.5.

CONCLUSIONS

We report a globally feasible and effective strategy avoiding craniospinal radiation in the treatment of infant medulloblastoma, including a robust molecular correlation along with neurocognitive outcomes.

Tandem High-dose Chemotherapy without Craniospinal Irradiation in Treatment of Non-metastatic Malignant Brain Tumors in Very Young Children

BACKGROUND

Infants and very young children with malignant brain tumors have a poorer survival and a higher risk for neurologic deficits. The present study evaluated the feasibility and effectiveness of multimodal treatment including tandem high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT) in minimizing use of radiotherapy (RT) in very young children with non-metastatic malignant brain tumors.

METHODS

Twenty consecutive patients younger than 3 years were enrolled between 2004 and 2017. Tandem HDCT/auto-SCT was performed after six cycles of induction chemotherapy. Local RT was administered only to patients with post-operative gross residual tumor at older than 3 years. Since September 2015, early post-operative local RT for patients with atypical teratoid/rhabdoid tumor or primitive neuroectodermal tumor was administered.

RESULTS

All 20 enrolled patients underwent the first HDCT/auto-SCT, and 18 proceeded to the second. Two patients died from toxicity during the second HDCT/auto-SCT, and four patients experienced relapse/progression (one localized and three metastatic), three of whom remained alive after salvage treatment including RT. A total of 17 patients remained alive at a median 7.8 (range, 2.5-5.7) years from diagnosis. Nine survivors received no RT, six survivors received local RT alone, and two survivors who experienced metastatic relapse after tandem HDCT/auto-SCT received both local and craniospinal RT. The 5-year overall, event-free, and craniospinal RT-free survival rates were 85.0% ± 8.0%, 70.0% ± 10.2%, and 75.0% ± 9.7%, respectively. Neuroendocrine and neurocognitive functions evaluated 5 years after tandem HDCT/auto-SCT were acceptable.

CONCLUSION

Our results suggest that non-metastatic malignant brain tumors in very young children could be treated with multimodal therapy including tandem HDCT/auto-SCT while minimizing RT, particularly craniospinal RT.

Promising survival rate but high incidence of treatment-related mortality after reduced-dose craniospinal radiotherapy and tandem high-dose chemotherapy in patients with high-risk medulloblastoma

BACKGROUND

In this study, we report the follow-up results of reduced dose of craniospinal radiotherapy (CSRT) followed by tandem high-dose chemotherapy (HDCT) in patients with high-risk medulloblastoma (MB).

METHODS

Newly diagnosed high-risk MB patients (metastatic disease, postoperative residual tumor >1.5 cm² , or large cell/anaplastic histology) over 3 years of age were enrolled in this study. Two cycles of pre-RT chemotherapy, radiotherapy (RT) including reduced-dose CSRT (23.4 or 30.6 Gy), four cycles of post-RT chemotherapy, and tandem HDCT were administered. NanoString and DNA sequencing were performed using archival tissues.

RESULTS

In all, 40 patients were enrolled, and molecular subgrouping was possible in 21 patients (2 wingless, 3 sonic hedgehog, 8 Group 3, and 8 group 4). All patients including two patients who experienced progression during the induction chemotherapy underwent HDCT. Relapse/progression occurred only in four patients (5-year cumulative incidence [CI] 10.4 ± 0.3%). However, six patients died from treatment-related mortality (TRM) (four acute TRMs and two late TRMs) resulting in 18.5 ± 0.5% of 5-year CI. Taken together, the 5-year event-free survival and overall survival were 71.1 ± 8.0% and 73.2 ± 7.9%, respectively. Late effects were evaluated in 25 patients and high-tone hearing loss, endocrine dysfunction, dyslipidemia, and growth retardation were common.

CONCLUSIONS

The strategy using tandem HDCT following reduced-dose CSRT showed promising results in terms of low relapse/progression rate; however, the high TRM rate indicates that modification of HDCT regimen and careful selection of patients who can benefit from HDCT will be needed in the future study.

Nonmetastatic Medulloblastoma of Early Childhood: Results From the Prospective Clinical Trial HIT-2000 and An Extended Validation Cohort

PURPOSE

The HIT-2000-BIS4 trial aimed to avoid highly detrimental craniospinal irradiation (CSI) in children < 4 years of age with nonmetastatic medulloblastoma by systemic chemotherapy, intraventricular methotrexate, and risk-adapted local radiotherapy.

PATIENTS AND METHODS

From 2001-2011, 87 patients received systemic chemotherapy and intraventricular methotrexate. Until 2006, CSI was reserved for nonresponse or progression. After 2006, local radiotherapy was introduced for nonresponders or patients with classic medulloblastoma (CMB) or large-cell/anaplastic medulloblastoma (LCA). DNA methylation profiles of infantile sonic hedgehog-activated medulloblastoma (SHH-INF) were subdivided into iSHH-I and iSHH-II subtypes in the HIT-2000-BIS4 cohort and a validation cohort (n = 71) from the HIT group and Russia.

RESULTS

Five years after diagnosis, patients with desmoplastic medulloblastoma (DMB) or medulloblastoma with extensive nodularity (MBEN; n = 42) had 93% progression-free survival (5y-PFS), 100% overall survival (5y-OS), and 93% CSI-free (5y-CSI-free) survival. Patients with CMB/LCA (n = 45) had 37% 5y-PFS, 62% 5y-OS, and 39% 5y-CSI-free survival. Local radiotherapy did not improve survival in patients with CMB/LCA. All DMB/MBEN assessed by DNA methylation profiling belonged to the SHH-INF subgroup. Group 3 patients (5y-PFS, 36%; n = 14) relapsed more frequently than the SHH-INF group (5y-PFS, 93%; n = 28) or group 4 patients (5y-PFS, 83%; n = 6; P < .001). SHH-INF split into iSHH-I and iSHH-II subtypes in HIT-2000-BIS4 and the validation cohort, without prognostic impact (5y-PFS: iSHH-I, 73%, v iSHH-II, 83%; P = .25; n = 99). Intelligence quotient (IQ) was significantly lower in patients after CSI (mean IQ, 90 [no radiotherapy], v 74 [CSI]; P = .012).

CONCLUSION

Systemic chemotherapy and intraventricular methotrexate led to favorable survival in both iSHH subtypes of SHH-activated DMB/MBEN with acceptable neurotoxicity. Survival in patients with non-wingless (WNT)/non-SHH disease with CMB/LCA was not improved by local radiotherapy. Patients with group 4 disease had more favorable survival rates than those with group 3 medulloblastoma.

Transcriptional profiling of medulloblastoma with extensive nodularity (MBEN) reveals two clinically relevant tumor subsets with VSNL1 as potent prognostic marker

Medulloblastoma with extensive nodularity (MBEN) is one of the few central nervous system (CNS) tumor entities occurring in infants which is traditionally associated with good to excellent prognosis. Some MBEN, however, have been reported with an unfavorable clinical course. We performed an integrated DNA/RNA-based molecular analysis of a multi-institutional MBEN cohort (n = 41) to identify molecular events which might be responsible for variability in patients' clinical outcomes. RNA sequencing analysis of this MBEN cohort disclosed two clear transcriptome clusters (TCL) of these CNS tumors: "TCL1 MBEN" and "TCL2 MBEN" which were associated with various gene expression signatures, mutational landscapes and, importantly, prognosis. Thus, the clinically unfavorable "TCL1 MBEN" subset revealed transcriptome signatures composed of cancer-associated signaling pathways and disclosed a high frequency of clinically relevant germline PTCH1/SUFU alterations. In contrast, gene expression profiles of tumors from the clinically favorable "TCL2 MBEN" subgroup were associated with activation of various neurometabolic and neurotransmission signaling pathways, and germline SHH-pathway gene mutations were extremely rare in this transcriptome cluster. "TCL2 MBEN" also revealed strong and ubiquitous expression of VSNL1 (visinin-like protein 1) both at the mRNA and protein level, which was correlated with a favorable clinical course. Thus, combining mutational and epigenetic profiling with transcriptome analysis including VSNL1 immunohistochemistry, MBEN patients could be stratified into clinical risk groups of potential value for subsequent treatment planning.

Leptomeningeal malignancy of childhood: sharing learning between childhood leukaemia and brain tumour trials

Leptomeningeal malignancy complicates childhood cancers, including leukaemias, brain tumours, and solid tumours. In leukaemia, such malignancy is thought to invade leptomeninges via the vascular route. In brain tumours, dissemination from the primary tumour, before or after surgery, via CSF pathways is assumed; however, evidence exists to support the vascular route of dissemination. Success in treating leptomeningeal malignancy represents a rate-limiting step to cure, which has been successfully overcome in leukaemia with intensified systemic therapy combined with intra-CSF therapy, which replaced cranial radiotherapy for many patients. This de-escalated CNS-directed therapy is still associated with some neurotoxicity. The balanced benefit justifies exploration of ways to further de-escalate CNS-directed therapy. For primary brain tumours, standard therapy is craniospinal radiotherapy, but attendant risk of acute and delayed brain injury and endocrine deficiencies compounds post-radiation impairment of spinal growth. Alternative ways of treating leptomeninges by intensifying drug therapy delivered to CSF are being investigated-preliminary evidence suggests improved outcomes. This Review seeks to describe methods of intra-CSF drug delivery and drugs in use, and consider how the technique could be modified and additional drugs might be selected for this route of administration.

Ventricular Cerebrospinal Fluid Sampling in Pediatric Diffuse Midline Glioma Patients: Institutional Experience and Review of the Literature

Purpose: Increasing evidence suggests that circulating biomarkers may serve diagnostic and longitudinal monitoring purposes in pediatric neuro-oncology. Mutant tumor DNA is detectable in the cerebrospinal fluid (CSF) of pediatric diffuse midline glioma (DMG) patients and quantity can reflect disease burden. CSF sampling ("liquid biopsy") via a CSF access device could therefore play a role in DMG management. Therefore, we set to evaluate the incidence of hydrocephalus (HCP) in DMG patients, and to characterize ventricular reservoir placement and access practices. Methods: A single institution retrospective review of DMG patients ≤21-years-old was performed (1984-2019). MEDLINE searches for reports of ventricular reservoir or shunt placement in DMG, and reservoir access for intraventricular chemotherapy (IVC) were performed. Results: At our institution, 62.6% of DMG patients (67/108) required intervention for HCP: 19.4% provided transient CSF access (ETV alone n = 3, EVD n = 8, unspecified n = 2), and 80.6% permanent CSF access (ETV + reservoir n = 13, shunt n = 41). Further, 22/34 patients with initially transient CSF devices required conversion to a permanent device. Five devices were revised for malfunction, one for infection. Seventeen articles cited HCP in 22 to 100% of DMG patients. IVC administration was described in 632 patients (seven articles), with 42 infectious and 63 non-infectious complications. Conclusions: Management of HCP is often necessary in children with DMG. Given the low rate of clinical risk associated with VAD placement and access, and the potential utility of longitudinal disease monitoring via CSF analysis, VAD placement could be considered in future clinical trials to guide DMG treatment.

Tumor bed proton irradiation in young children with localized medulloblastoma

BACKGROUND

Radiotherapy is often deferred in very young children with medulloblastoma, in favor of more intense chemotherapy and stem cell rescue; however, posterior fossa radiation has been shown to improve overall survival (OS) and event-free survival compared with adjuvant chemotherapy alone. This study was performed to assess the OS, recurrence-free survival (RFS), patterns of failure, and clinical toxicity for children aged five and under who received focal proton radiation to the tumor bed alone.

PROCEDURE

From 2010 to 2017, 14 patients with newly diagnosed medulloblastoma at one institution received tumor bed irradiation following surgery and chemotherapy. The median age of the patients was 40 months (range, 10.9-62.9 months).

RESULTS

With a median follow-up of 54 months, four patients relapsed: three within the central nervous system (CNS) outside of the posterior fossa, and one within the tumor bed after subtotal resection. All relapses occurred within 28 months after the completion of radiation therapy. Five-year OS and RFS for this cohort of patients were 84% (95% CI, 48%-96%) and 70% (95% CI, 38%-88%), respectively. One patient experienced significant tumor regrowth soon after completion of radiation, autopsy showed viable tumor and necrosis near and within the brainstem, with relation to radiation unknown; however, no other acute clinical toxicities greater than grade 2 were observed in this group of patients. In the nine patients with available performance status follow-up, no significant changes in Lansky performance status were observed.

CONCLUSIONS

Five-year OS and RFS following tumor bed irradiation in young children with medulloblastoma appear to be improved compared with other studies that forego the use of radiation therapy in this patient population. This approach should be further investigated in young children with medulloblastoma.

Desmoplastic nodular medulloblastoma in young children: a management dilemma

Background

Children with desmoplastic nodular medulloblastoma (DNMB) have excellent survival, leading multiple groups globally to attempt reduction of treatment-related morbidity. In 2013, the Children's Oncology Group began a clinical trial (ACNS1221) eliminating both radiation therapy (RT) and intraventricular methotrexate for children under 3 years of age with localized DNMB, aiming to build upon the excellent outcomes of the German HIT trials. ACNS1221 has recently closed due to increased incidence of recurrences noted at the 2-year interim analysis, raising important questions regarding optimal therapy for DNMB.

Methods

A review of major clinical trials that included children with DNMB was performed through July 2017.

Results

One hundred and eighty-eight DNMB patients enrolled on 11 prospective clinical trials were identified. The use of marrow-ablative chemotherapy and autologous hematopoietic cell rescue (AuHCR) or treatment with intraventricular methotrexate has been associated with excellent outcomes. RT was usually required for patients with evidence of disease at the end of therapy.

Conclusions

The minimal intensity and duration of chemotherapy required to maximally cure children with DNMB without need of RT remains unknown. Further trials are required to better identify a subset of DNMB patients who can be cured without marrow-ablative chemotherapy or intraventricular methotrexate.

Continuous and bolus intraventricular topotecan prolong survival in a mouse model of leptomeningeal medulloblastoma

Leptomeningeal metastasis remains a difficult clinical challenge. Some success has been achieved by direct administration of therapeutics into the cerebrospinal fluid (CSF) circumventing limitations imposed by the blood brain barrier. Here we investigated continuous infusion versus bolus injection of therapy into the CSF in a preclinical model of human Group 3 medulloblastoma, the molecular subgroup with the highest incidence of leptomeningeal disease. Initial tests of selected Group 3 human medulloblastoma cell lines in culture showed that D283 Med and D425 Med were resistant to cytosine arabinoside and methotrexate. D283 Med cells were also resistant to topotecan, whereas 1 μM topotecan killed over 99% of D425 Med cells. We therefore introduced D425 Med cells, modified to express firefly luciferase, into the CSF of immunodeficient mice. Mice were then treated with topotecan or saline in five groups: continuous intraventricular (IVT) topotecan via osmotic pump (5.28 μg/day), daily bolus IVT topotecan injections with a similar daily dose (6 μg/day), systemic intraperitoneal injections of a higher daily dose of topotecan (15 μg/day), daily IVT pumped saline and daily intraperitoneal injections of saline. Bioluminescence analyses revealed that both IVT topotecan treatments effectively slowed leptomeningeal tumor growth in the brains. Histological analysis showed that they were associated with localized brain necrosis, possibly due to backtracking of topotecan around the catheter. In the spines, bolus IVT topotecan showed a trend towards slower tumor growth compared to continuous (pump) IVT topotecan, as measured by bioluminescence. Both continuous and bolus topotecan IVT showed longer survival compared to other groups. Thus, both direct IVT topotecan CSF delivery methods produced better anti-medulloblastoma effect compared to systemic therapy at the dosages used here.

Clinical Characteristics and Outcome of Children With Relapsed Medulloblastoma: A Retrospective Study at a Single Center in China

Relapsed medulloblastoma (MB) has a dire prognosis, and chemotherapy remains the main therapeutic option. We retrospectively analyzed the clinical characteristics and survival rates of 60 Chinese children with relapsed MB. The patients received 11 cycles of chemotherapy in sequence, followed by 12 cycles of oral temozolomide and etoposide. Thirty patients were simultaneously administered intrathecal methotrexate (IT-MTX). The Kaplan-Meier method was used to determine survival rates; the patients' median survival time after relapse was 2.8 years, 5-year progression-free survival (PFS) and overall survival (OS) rates were 26.7%±5.7% and 31.6%±6.9%, respectively. There was no significant difference between these rates according to histology or molecular subgroup. Tumor cells were detected in the cerebrospinal fluid of over 40% of patients; such patients had significantly shorter OS and PFS rates. Patients who received IT-MTX showed significantly longer survival than those who did not (3.73 vs. 2.06 y, respectively, P=0.000); the corresponding 5-year PFS and OS rates were 43.3%±9.0% versus 10.0%±5.5% and 49.5%±11.1% versus 14.6%±6.9%, respectively (P=0.000). In addition, tumor cell-positive cerebrospinal fluid and IT-MTX use significantly influenced PFS and OS in relapsed patients. Taken together, our data show that IT-MTX improves the survival of patients with relapsed MB.

Glioblastoma Chemoresistance: The Double Play by Microenvironment and Blood-Brain Barrier

For glioblastoma, the tumor microenvironment (TME) is pivotal to support tumor progression and therapeutic resistance. TME consists of several types of stromal, endothelial and immune cells, which are recruited by cancer stem cells (CSCs) to influence CSC phenotype and behavior. TME also promotes the establishment of specific conditions such as hypoxia and acidosis, which play a critical role in glioblastoma chemoresistance, interfering with angiogenesis, apoptosis, DNA repair, oxidative stress, immune escape, expression and activity of multi-drug resistance (MDR)-related genes. Finally, the blood brain barrier (BBB), which insulates the brain microenvironment from the blood, is strongly linked to the drug-resistant phenotype of glioblastoma, being a major physical and physiological hurdle for the delivery of chemotherapy agents into the brain. Here, we review the features of the glioblastoma microenvironment, focusing on their involvement in the phenomenon of chemoresistance; we also summarize recent advances in generating systems to modulate or bypass the BBB for drug delivery into the brain. Genetic aspects associated with glioblastoma chemoresistance and current immune-based strategies, such as checkpoint inhibitor therapy, are described too.

Neurological complications of systemic tumor therapy

The treatment of malignant tumors has considerably improved in recent years, and also the number of "long term cancer survivors" is increasing.The spectrum of anti-tumoral agents is increasing at a fast pace and in addition to conventional therapies such as surgery, radiotherapy, and chemotherapy, new drugs with entirely new mechanisms are appearing. Side effects of old and new drugs can affect the central and peripheral nervous system, the neuromuscular junction, and muscle. These side effects often have to be distinguished from other causes and need neurological expertise. Although the majority of patients still receive conventional therapies, several new strategies such as immune therapies are being implemented. These drugs have also drug specific side effects, which do not always follow the classical principles of "toxicity."This review focuses on the well-known and described side effects of conventional cancer therapies and adds new observations on new drugs.

Triptolide inhibits the proliferation and migration of medulloblastoma Daoy cells by upregulation of microRNA-138

Medulloblastoma is a primitive neuroectodermal-derived brain tumor and the most common malignant brain tumor in children. Triptolide (TPL) is the major active component extracted from Tripterygium wilfordii Hook F. This study aimed to explore the effects of TPL on medulloblastoma cell proliferation, migration, and apoptosis, as well as the underlying possible molecular mechanism. Viability, proliferation, and apoptosis of Daoy cells were measured using cell counting kit-8 assay, 5-bromo-2'-deoxyuridine incorporation assay, and Guava Nexin assay, respectively. Cell migration was detected using two-chamber transwell assay and wound healing assay. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to determine the relative expression of microRNA-138 (miR-138) in Daoy cells. Cell transfection was used to change the expression of miR-138 in cells. Western blot analysis was used to analyze the expression of key factors involved in cell apoptosis, cell migration, the phosphatidylinositol 3-kinase (PI3K)/protein kinase 3 (AKT) pathway, and the Notch pathway in Daoy cells. We found that TPL significantly inhibited the viability, proliferation, and migration of Daoy cells but promoted Daoy cell apoptosis. The expression levels of matrix metalloproteinases (MMP)-2 and MMP-9 after TPL treatment were decreased. The expression of miR-138 in Daoy cells after TPL treatment was increased. Suppression of miR-138 obviously reversed the TPL-induced Daoy cell proliferation, migration inhibition, and cell apoptosis enhancement, as well as the inactivation of the PI3K/AKT and Notch pathways. Cyclin-dependent kinase 6 (CDK6) was a direct target gene of miR-138, which might be involved in the antitumor effects of TPL on Daoy cells. In conclusion, our study verified that TPL exerted anticancer effects on medulloblastoma cells possibly via upregulating miR-138 and inactivating the PI3K/AKT and Notch pathways.

Risk-adapted therapy for young children with medulloblastoma (SJYC07): therapeutic and molecular outcomes from a multicentre, phase 2 trial

BACKGROUND

Young children with medulloblastoma have a poor overall survival compared with older children, due to use of radiation-sparing therapy in young children. Radiotherapy is omitted or reduced in these young patients to spare them from debilitating long-term side-effects. We aimed to estimate event-free survival and define the molecular characteristics associated with progression-free survival in young patients with medulloblastoma using a risk-stratified treatment strategy designed to defer, reduce, or delay radiation exposure.

METHODS

In this multicentre, phase 2 trial, we enrolled children younger than 3 years with newly diagnosed medulloblastoma at six centres in the USA and Australia. Children aged 3-5 years with newly diagnosed, non-metastatic medulloblastoma without any high-risk features were also eligible. Eligible patients were required to start therapy within 31 days from definitive surgery, had a Lansky performance score of at least 30, and did not receive previous radiotherapy or chemotherapy. Patients were stratified postoperatively by clinical and histological criteria into low-risk, intermediate-risk, and high-risk treatment groups. All patients received identical induction chemotherapy (methotrexate, vincristine, cisplatin, and cyclophosphamide), with high-risk patients also receiving an additional five doses of vinblastine. Induction was followed by risk-adapted consolidation therapy: low-risk patients received cyclophosphamide (1500 mg/m2 on day 1), etoposide (100 mg/m2 on days 1 and 2), and carboplatin (area under the curve 5 mg/mL per min on day 2) for two 4-week cycles; intermediate-risk patients received focal radiation therapy (54 Gy with a clinical target volume of 5 mm over 6 weeks) to the tumour bed; and high-risk patients received chemotherapy with targeted intravenous topotecan (area under the curve 120-160 ng-h/mL intravenously on days 1-5) and cyclophosphamide (600 mg/m2 intravenously on days 1-5). After consolidation, all patients received maintenance chemotherapy with cyclophosphamide, topotecan, and erlotinib. The coprimary endpoints were event-free survival and patterns of methylation profiling associated with progression-free survival. Outcome and safety analyses were per protocol (all patients who received at least one dose of induction chemotherapy); biological analyses included all patients with tissue available for methylation profiling. This trial is registered with ClinicalTrials.gov, number NCT00602667, and was closed to accrual on April 19, 2017.

FINDINGS

Between Nov 27, 2007, and April 19, 2017, we enrolled 81 patients with histologically confirmed medulloblastoma. Accrual to the low-risk group was suspended after an interim analysis on Dec 2, 2015, when the 1-year event-free survival was estimated to be below the stopping rule boundary. After a median follow-up of 5·5 years (IQR 2·7-7·3), 5-year event-free survival was 31·3% (95% CI 19·3-43·3) for the whole cohort, 55·3% (95% CI 33·3-77·3) in the low-risk cohort (n=23) versus 24·6% (3·6-45·6) in the intermediate-risk cohort (n=32; hazard ratio 2·50, 95% CI 1·19-5·27; p=0·016) and 16·7% (3·4-30·0) in the high-risk cohort (n=26; 3·55, 1·66-7·59; p=0·0011; overall p=0·0021). 5-year progression-free survival by methylation subgroup was 51·1% (95% CI 34·6-67·6) in the sonic hedgehog (SHH) subgroup (n=42), 8·3% (95% CI 0·0-24·0%) in the group 3 subgroup (n=24), and 13·3% (95% CI 0·0-37·6%) in the group 4 subgroup (n=10). Within the SHH subgroup, two distinct methylation subtypes were identified and named iSHH-I and iSHH-II. 5-year progression-free survival was 27·8% (95% CI 9·0-46·6; n=21) for iSHH-I and 75·4% (55·0-95·8; n=21) for iSHH-II. The most common adverse events were grade 3-4 febrile neutropenia (48 patients [59%]), neutropenia (21 [26%]), infection with neutropenia (20 [25%]), leucopenia (15 [19%]), vomiting (15 [19%]), and anorexia (13 [16%]). No treatment-related deaths occurred.

INTERPRETATION

The risk-adapted approach did not improve event-free survival in young children with medulloblastoma. However, the methylation subgroup analyses showed that the SHH subgroup had improved progression-free survival compared with the group 3 subgroup. Moreover, within the SHH subgroup, the iSHH-II subtype had improved progression-free survival in the absence of radiation, intraventricular chemotherapy, or high-dose chemotherapy compared with the iSHH-I subtype. These findings support the development of a molecularly driven, risk-adapted, treatment approach in future trials in young children with medulloblastoma.

FUNDING

American Lebanese Syrian Associated Charities, St Jude Children's Research Hospital, NCI Cancer Center, Alexander and Margaret Stewart Trust, Sontag Foundation, and American Association for Cancer Research.

A Retrospective Study of Progression-Free and Overall Survival in Pediatric Medulloblastoma Based on Molecular Subgroup Classification: A Single-Institution Experience

Background

Medulloblastoma (MB) has been classified into four core subgroups according to the transcriptional profile in recent years. However, some disagreement among researchers remains regarding the prognoses and most effective treatments of the different subgroups with different age distributions.

Objective

The objective of this study was to analyze MB prognosis in children population based on the classification of four molecular subgroups.

Methods

From January 2011 to January 2013, 84 consecutive MB patients aged underwent tumor removal at Beijing Tiantan Hospital. A total of 55 patients who ranged in age from 4 to 18 years underwent detailed follow-up. Molecular subgrouping was performed using RT-PCR.

Results

The 2-year progression-free survival (PFS) and overall survival (OS) rates for the entire cohort were 76.2 ± 5.8 and 81.8 ± 5.2%, respectively. Univariate analysis revealed that the Group 4 patients had a better survival (2-year OS, 90.6 ± 5.2%) than the SHH subgroup (P = 0.002) and Group 3 patients (P = 0.008). Only two of the 23 non-metastasized Group 4 patients relapsed, and chemotherapy did significantly affect these patients (PFS, P = 0.685). One out of five WNT patients had tumor relapse and died at last. Large cell/anaplastic (LC/A) histology and chemotherapy were independent risk factors in multivariate analysis.

Conclusion

In our study, the non-metastasized Group 4 patients had an excellent prognosis. The SHH subgroup and Group 3 patients had worst prognoses. LC/A histology had a dismal prognosis in our cohorts, which warrants intensive treatment.

Recent advances in engineered chitosan-based nanogels for biomedical applications

Recent progress in the preparation and biomedical applications of engineered chitosan-based nanogels has been comprehensively reviewed.

Treatment of Children and Adolescents With Metastatic Medulloblastoma and Prognostic Relevance of Clinical and Biologic Parameters

Purpose To assess an intensified treatment in the context of clinical and biologic risk factors in metastatic medulloblastoma. Patients and Methods Patients (4 to 21 years old, diagnosed between 2001 and 2007) received induction chemotherapy, dose-escalated hyperfractionated craniospinal radiotherapy, and maintenance chemotherapy. Subgroup status and other biologic parameters were assessed. Results In 123 eligible patients (median age, 8.2 years old; median follow-up, 5.38 years), 5-year event-free survival (EFS) and overall survival (OS) were 62% (95% CI, 52 to 72) and 74% (95% CI, 66 to 82), respectively. OS was superior compared with the precedent HIT '91 trial. The 5-year EFS and OS were both 89% (95% CI, 67 to 100) for desmoplastic/nodular (n = 11), 61% (95% CI, 51 to 71) and 75% (95% CI, 65 to 85) for classic (n = 107), and 20% (95% CI, 0 to 55) and 40% (95% CI, 0 to 83) for large-cell/anaplastic (n = 5) medulloblastoma ( P < .001 for EFS; P = .001 for OS). Histology (hazard ratio, 0.19 for desmoplastic/nodular and 45.97 for large-cell/anaplastic medulloblastoma) and nonresponse to the first chemotherapy cycle (hazard ratio, 1.97) were independent risk factors (EFS). Among 81 (66%) patients with tumor material, 5-year EFS and OS differed between low-risk (wingless [WNT], n = 4; both 100%), high-risk ( MYCC/ MYCN amplification; n = 5, both 20%), and intermediate-risk patients (neither; n = 72, 63% and 73%, respectively). Survival rates were different between molecular subgroups (WNT, n = 4; sonic hedgehog [SHH; n = 4]; group 4 [n = 41]; group 3 with [n = 3] or without [n = 17] MYCC/MYCN amplification; P < .001). All cases showed p53 immuno-negativity. There was no association between patients with nonresponding tumors to induction chemotherapy and WNT ( P = .143) or MYCC/MYCN status ( P = .075), histologic subtype ( P = .814), or molecular subtype ( P = .383), as assessed by Fisher's exact test. Conclusion This regimen was feasible and conferred overall favorable survival. Our data confirm the relevance of subgroup status and biologic parameters (WNT/ MYCC/ MYCN status) in a homogeneous prospective trial population, and show that metastatic group 3 patients do not uniformly have poor outcomes. Biologic subgroup, MYCC/ MYCN status, response to induction chemotherapy, and histologic subtype may serve for improved treatment stratification.

Intraventricular etoposide safety and toxicity profile in children and young adults with refractory or recurrent malignant brain tumors

Systemic administration of etoposide is effective in treating metastatic, recurrent or refractory brain tumors, but penetration into the cerebrospinal fluid is extremely poor. This study was designed to determine the safety and toxicity profile of intraventricular etoposide administration and was affiliated with the prospective, multicenter, nonblinded, nonrandomized, multi-armed HIT-REZ-97 trial. The study enrolled 68 patients, aged 1.1-34.6 (median age 11 years). Adverse events that could possibly be related to intraventricular etoposide therapy were documented and analyzed. Intraventricular etoposide was simultaneously administered with either oral or intravenous chemotherapy in 426 courses according to three major schedules varying in dosing (0.25-1 mg), frequency of administration (bolus injection, every 12 or 24 h), course duration (5-10 days) and length of interval between courses (2-5 weeks). Potential treatment-related adverse effects included transient headache, seizures, infection of the reservoir, nausea and neuropsychological symptoms. Hematological side effects were not observed. One patient, with history of multiple prior therapies, who received long-term intraventricular and oral etoposide treatment developed acute myeloid leukemia as a secondary malignancy. Overall intraventricular etoposide is well tolerated. The results of this study have warranted a phase II trial to determine the effectiveness of this regimen in disease stages with very limited therapeutic options.