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Children with brain tumors often carry germline mutations that have long been known to contribute to tumorigenesis and treatment response. However, less is known about how germline mutations may impact developmental and behavioral outcomes for children with tumors of the central nervous system (CNS). As the molecular mechanisms governing cancerous and normal tissue expand, we hypothesize that particular germline variants may impact baseline neurocognitive function and/or treatment-induced toxicities. In this preliminary study, 10 children on the Head Start 4 trial diagnosed with medulloblastoma were assessed for baseline adaptive functioning using the Adaptive Behavior Assessment System Third Edition (ABAS-III) and germline whole-exome sequencing was performed. After filtering for high impact variants, Welch’s T-tests were used to identify mutations associated with lower ABAS-III General Adaptive Composite (GAC) scores, reflecting developmental and adaptive behavior delays compared with peers their age. We found 20 genes with alterations associated with lower scores with P-values less than 0.05, although none met FDR significance cutoffs. Genes found to be significant included LAMC1 (P=0.04) and KRTAP1-1 (P=0.045), which encode members of the laminin and keratin family and are involved in extracellular matrix adhesion. Mutations in PITX1, a known suppressor of RAS, were also associated with lower ABAS-III GAC scores (P=0.007). We suspect that follow-up studies with more patients will reveal alterations in cell-to-cell communication and signal transduction pathways, as these are common molecular perturbations in tumors that would likely impact regular CNS function. Future research with larger cohorts is essential to validate these findings and to improve our understanding of the functional impact of germline variants on both tumor and regular tissue biology, allowing for a more comprehensive view of the spectrum of neurodevelopmental impairment and novel strategies to circumvent these impairments. Funding: Thrasher Research Fund (JF, AC). R01CA108633, RC2CA148190, U10CA180850(NCI), and OSUCCC (AC).

Background Glioblastoma (GBM) remains one of the least successfully treated cancers. It is essential to understand the basic biology of this lethal disease and investigate novel pharmacological targets to treat GBM. The aims of this study were to determine the biological consequences of elevated expression of ΔNp73, an N-terminal truncated isoform of TP73, and to evaluate targeting of its downstream mediators, the angiopoietin 1 (ANGPT1)/tunica interna endothelial cell kinase 2 (Tie2) axis, by using a highly potent, orally available small-molecule inhibitor (rebastinib) in GBM. Methods ΔNp73 expression was assessed in glioma sphere cultures, xenograft glioblastoma tumors, and glioblastoma patients by western blot, quantitative reverse transcription PCR, and immunohistochemistry. Immunoprecipitation, chromatin immunoprecipitation (ChiP) and sequential ChIP were performed to determine the interaction between ΔNp73 and E26 transformation-specific (ETS) proto-oncogene 2 (ETS2) proteins. The oncogenic consequences of ΔNp73 expression in glioblastomas were examined by in vitro and in vivo experiments, including orthotopic zebrafish and mouse intracranial-injection models. Effects of rebastinib on growth of established tumors and survival were examined in an intracranial-injection mouse model. Results ΔNp73 upregulates both ANGPT1 and Tie2 transcriptionally through ETS conserved binding sites on the promoters by interacting with ETS2. Elevated expression of ΔNp73 promotes tumor progression by mediating angiogenesis and survival. Therapeutic targeting of downstream ΔNp73 signaling pathways by rebastinib inhibits growth of established tumors and extends survival in preclinical models of glioblastoma. Conclusion Aberrant expression of ΔNp73 in GBM promotes tumor progression through autocrine and paracrine signaling dependent on Tie2 activation by ANGPT1. Disruption of this signaling by rebastinib improves tumor response to treatment in glioblastoma.

Metastatic disease at initial presentation of intracranial ependymoma is an uncommon occurrence with only rare reports of survival and is reportedly more prevalent in the youngest of children. Clinical and molecular characteristics associated with metastatic presentation, their prognostic implications, as well as optimal treatment options for such patients, have not been identified. CASE REPORT: A seven months old child presented with posterior fossa anaplastic ependymoma; following sub-total resection of primary tumor, a spine MRI revealed leptomeningeal dissemination along the cervical spinal cord and nerve roots of the cauda equina. The patient was successfully treated with five cycles of intensive induction chemotherapy (as per Head Start with high-dose methotrexate) followed by three sequential cycles of marrow-ablative chemotherapy and autologous hematopoietic progenitor cell rescue (AuHPCR) without irradiation; he is currently without evidence of the disease now 60 months following initial diagnosis. MOLECULAR/GENOMIC RESULTS: The patient was enrolled on a patient-centric comprehensive molecular profiling protocol, which included paired tumor-normal whole-exome sequencing, RNA sequencing of the disease-involved tissue, and DNA methylation classification. The genomic profile of the tumor was relatively unremarkable, revealing only a terminal gain of chromosome 3p and a terminal deletion of chromosome 22q, suggestive of an unbalanced translocation. Using RNA sequencing, we identified a novel SPECC1L-RAF1 gene fusion. The tumor harbors unique transcriptomic and DNA methylation profiles, failing to discretely classify with well-established ependymoma subgroups. CONCLUSION: Use of genomic profiling techniques provides meaningful information for disease characterization allowing for further expansion of the molecular spectrum associated with malignant disease.

BACKGROUND Wnt-MB infers an excellent prognosis, and metastatic disease is rare. However, specific treatment strategies and patterns of failure for patients with recurrent Wnt-MB are unknown. We report two cases of recurrent beta-catenin nucleopositive Wnt-MBs treated with an irradiation-sparing strategy, incorporating HDCx/AuHPCR. PATIENT 1: A nine-year-old female experienced local recurrence of a non-metastatic Wnt-MB nine months after gross total resection (GTR) followed by 18Gy craniospinal irradiation (CSI) with primary site boost to 54Gy, accompanied by weekly vincristine, followed by a maintenance regimen of nine cycles of cisplatin/lomustine/vincristine alternating with cyclophosphamide/vincristine every third cycle. GTR of the relapsed tumor was followed by three cycles of HDCx/AuHPCR. She is disease-free for over three years following relapse treatment. PATIENT 2: A 17-year-old male initially underwent GTR, followed by 23.4Gy CSI with 54Gy posterior fossa boost with concomitant weekly vincristine, followed by a maintenance regimen that included nine alternating cycles of vincristine/lomustine/cisplatin and cyclophosphamide/vincristine. Isolated right frontal horn metastatic recurrence developed 19 months post-treatment; three cycles of irinotecan/temozolomide/bevacizumab and gamma-knife radiosurgery produced complete response. A second isolated metastatic recurrence within the left frontal horn occurred 13 months post-treatment, which was treated with two cycles of cyclophosphamide/etoposide followed by two cycles of HDCx/AuHPCR. MRI of the brain showed no residual tumor one month post-treatment. He currently awaits follow-up stereotactic radiosurgery. CONCLUSION Patients with recurrent Wnt-MB may be treated with curative intent using a multi-disciplinary approach that includes HDCx/AuHPCR, and minimization or avoidance of re-irradiation.

BACKGROUND We report the outcomes of patients with pineoblastoma enrolled on the Head Start I-III trials. METHODS Twenty-three children were enrolled between 1991–2009. Treatment included maximal surgical resection followed by five cycles of intensive-chemotherapy and consolidation with marrow-ablative chemotherapy and autologous hematopoietic cell rescue (HDCx/AuHCR). Irradiation following consolidation was reserved for children over six years of age or those with residual tumor at the end of induction. RESULTS The median age was 3.12 years (range:0.44–5.72). Three patients withdrew from the protocols and two patients experienced chemotherapy-related mortality. Eight patients experienced progressive disease (PD) during induction chemotherapy. Ten patients received HDCx/AuHCR; eight experienced PD post-consolidation. Seven patients received craniospinal irradiation (CSI) with a median dose of 20.7 Gy (range:18–36 Gy) with boost(s) (median dose 27 Gy, range:18–36 Gy); three received CSI as adjuvant therapy (2 post-HDCx/AuHCR) and four upon progression/recurrence. The 5-year progression-free survival (PFS) and overall survival (OS) were 9.7% (95%,CI:2.6–36.0%) and 13% (95%,CI:4.5–37.5%), respectively. Three patients survived beyond five years. Nineteen patients relapsed in the following sites: local site (n=4), distal site (n=6), local and distal sites (n=9). Favorable OS prognostic factors were CSI (hazard ratio (HR)=0.30 (0.11–0.86), p=0.025), and HDCx/AuHCR (HR=0.40 (0.16–0.99), p=0.047). CONCLUSION CSI and HDCx/AuHCR were statistically associated with improved survival. The overall poor outcomes and high PD rate during later induction cycles and following consolidation chemotherapy warrants consideration of fewer induction cycles before consolidation and the intensification of consolidation with multiple cycles of marrow-ablative chemotherapy.

BACKGROUND We report a unique case of spinal ependymoma with classic histology and aggressive clinical behavior which harbored a focal MYC (8q24) amplification. CASE REPORT: A-12-year old male presented with a three months history of back pain and acute onset weakness with ataxia. A spine MRI revealed an avidly enhancing intradural, extramedullary mass occupying the dorsal spinal canal from C6 through T2. The tumor demonstrated mild diffusion restriction and was associated with severe cord compression and mild edema. He underwent gross total resection. Pathological diagnosis was classic grade II ependymoma. Eleven months later, he re-presented with acute onset lower extremity paresthesia and left-handed weakness. Spine MRI demonstrated tumor recurrence extending from C2 through T1-T2 with resultant severe cord compression, again demonstrating avid enhancement and restricted diffusion. He underwent subtotal resection of the mass and focal proton beam irradiation. MOLECULAR CHARACTERISTICS: The patient was enrolled on an institutional comprehensive genomic profiling protocol. The tumor’s copy number profile was complex, including homozygous loss of 17p and notably, amplification of the MYC oncogene. Using fluorescence in situ hybridization, we identified >20 copies of MYC in interphase cells, confirming the gene amplification, while two copies of MYCN (2p24) were seen. DNA methylation further classified this tumor as clustering near posterior fossa group A (score=0.6073) tumors. CONCLUSION We report a unique case of an adolescent male with aggressive spinal ependymoma harboring focal MYC amplification. Testing for MYC amplification may be reasonable in newly-diagnosed spinal ependymomas to aid in characterization.

BACKGROUND: Pineoblastoma is a rare malignant pineal region tumor, the optimal management of which in young children remains unclear. METHODS: We report the outcomes of 23 children with pineoblastoma prospectively enrolled on three sequential Head Start (HS) trials between 1990 and 2009. The HS treatment strategy included maximal surgical resection followed by five cycles of intensive induction chemotherapy and consolidation with marrow-ablative chemotherapy and autologous hematopoietic cell rescue (HDCx/AuHCR). Irradiation following recovery from consolidation was reserved for children over six years old or with residual tumor. RESULTS: Data on 23 children with pineoblastoma including two with trilateral retinoblastoma aged 0.44–5.72 (median 3.12) years were analyzed. Median overall survival (OS) was 12 months (95% CI: 7.6–29.7 months). The 3-year progression-free survival (PFS) and OS were 14.5% (95% CI: 5.1–41.2%) and 17.4% (95% CI: 7.1–42.4%), respectively. Three patients were long-term survivors beyond 5 years. Eight patients experienced progressive disease (PD) during induction chemotherapy, six following the fourth and fifth cycles. Ten patients proceeded to consolidation with HDCx/AuHCR; eight experienced PD post-consolidation. Seven patients received craniospinal irradiation with boost(s) (median dose 20.7 (18–36) Gy), three patients as adjuvant therapy and four upon progression/recurrence. Favorable prognostic factors were administration of radiotherapy (hazard ratio (HR) for OS=0.30 (0.11–0.86), p

BACKGROUND: Medulloblastoma is the most common brain tumor in early childhood. Molecular profiling of medulloblastomas has resulted in a classification system including at least 4 major subtypes of disease, defining prognosis in patients treated largely on traditional chemotherapy and irradiation-based protocols. The Head Start Consortium has developed treatment protocols designed to avoid irradiation and its debilitating long-term side effects. The first three Head Start trials showed promising results; however, prospective genetic data are still lacking to evaluate whether molecular alterations can predict patient response to irradiation-avoiding treatment strategies. The Head Start 4 Protocol is a multi-national trial that incorporates non-mandatory, prospective tumor and blood collection for analysis in an attempt to address this question. Currently, 100% of patients enrolled to date have submitted samples for WES. METHODS: Paired blood and tumor samples (FFPE) from the first 10 medulloblastoma patients had WES (SureSelect Human All Exon V6+COSMIC) performed utilizing an Illumina Hiseq 4000. Data were processed using varscan v2.4.1 somatic command on tumor/normal pairs and annotated using Variant Effect Predictor from ensembl. Results were filtered at a threshold of 20 read depth or 40% variant allele frequency. Low-impact mutations were removed. Mutation profiles were compared with pediatric medulloblastoma gene mutation data from the PedcBioPortal and PeCan databases. RESULTS: A total of 903 mutation events were identified across 10 patients with each patient demonstrating mutations in one or more genes previously reported to be mutated in medulloblastoma. Two samples harbored SUFU mutations similar to those reported previously. CONCLUSIONS: These data show the feasibility of prospective high-dimensional mutational analysis using non-mandatory tissue submissions for pediatric medulloblastoma patients enrolled on the Head Start 4 Protocol. Copy-number and methylation analysis is ongoing. FUNDING: Thrasher Research Fund (JF, AC). R01CA108633, R01CA169368, RC2CA148190, U10CA180850-01 (NCI), Brain Tumor Funders Collaborative Grant, and OSUCCC (AC).

BACKGROUND Pediatric brain tumor classification has undergone significant evolution over the last decade requiring a high-level of expertise and diagnostic techniques. Such advances have created challenges for pathologists particularly in low-to-middle income countries (LMIC). We conduct weekly pediatric neuro-oncology teleconferences linking global pediatric neuro-oncologists from high-income countries (HIC) to review patients with pediatric subspecialists from Latin America. METHODS Three to five patients are discussed weekly and second neuropathology review is offered when a high-level of suspicion emerges of a questionable diagnosis based on clinical and radiographical information. Nationwide Children’s Hospital (NCH) provides second neuropathology review at no cost to institutions in Latin America that fulfill these criteria. RESULTS From July 2015 to December 2019 NCH reviewed 54 pathology samples from eleven Latin American countries. Of these, 33 (61.1%) cases resulted in diagnostic changes, of which 28 (51.8%) were significant, impacting treatment plans and overall patient outcomes. The remaining 21 (38.9%) confirmed institutional diagnosis; however, in eight of these 21 cases additional molecular information and/or further tumor subtyping unavailable in their home country at the time (eg: BRAF, RELA-fusion, medulloblastoma subtyping) was provided. CONCLUSIONS This study highlights the importance of centralized pathology review by institutions with the proper equipment, infrastructure and expertise in pediatric neuropathology. Furthermore, this documents the beneficial impact of teleconferencing for subspecialists in LMIC who must treat a wide variety of pediatric cancers with few resources and support. Additionally, our findings underscore the need for pediatric subspecialty training in LMIC.

INTRODUCTION Irradiation-sparing approaches are used in young children with medulloblastoma (MB) given the vulnerability of the developing brain to neurocognitive impairment. Limited data are available following relapse for these patients. We aimed to describe the management and outcomes of young children with MB who relapsed after initial treatment without craniospinal irradiation (CSI). METHODS International retrospective study including patients with MB diagnosed between 1995–2017, ≤ 72 months old, initially treated without CSI, who subsequently relapsed. RESULTS Data are available for 52 patients (32 male). Median age at initial diagnosis was 27 months (range, 6–72) with 24 being metastatic. Initial therapy included conventional chemotherapy alone or high-dose chemotherapy (HDC) in 21 and 31 subjects, respectively. Three received upfront focal irradiation. Molecular subgrouping, available for 24 tumors, included 9 SHH and 15 non-WNT/non-SHH. Median time to relapse was 13 months (range, 3–63). Relapse was local, disseminated or combined in 20, 15, and 16, respectively. Salvage therapy with curative intent was given in 42/52 patients, including CSI in 28 subjects (median dose 36Gy, 18–41.4) or focal irradiation in 5 others. Three received HDC only. At a median follow-up time of 46 months (range, 4–255), 25 (48%) were alive, including 7/9 SHH and 7/15 non-WNT/non-SHH. The 2- and 5-year OS was 67% and 56% (SE, 7%), respectively. Two of 3 patients with SHH who did not receive salvage radiotherapy are survivors. CONCLUSION A substantial proportion of young children who relapse following irradiation-sparing strategies can be salvaged. Neurocognitive and ototoxicity outcomes are being evaluated.

BACKGROUND Metastatic atypical teratoid/rhabdoid tumors (AT/RT) are aggressive central nervous system tumors that present during infancy and are associated with dismal outcomes. Patients receive multimodal treatment including surgical resection, systemic chemotherapy and one or more of intrathecal chemotherapy (IT), marrow-ablative chemotherapy with autologous hematopoietic cell rescue (AuHCR) and radiation therapy (XRT). While data regarding treatment modalities for AT/RT patients exist, no comprehensive data have been published regarding the metastatic patient population. METHODS We performed a meta-analysis of 1,578 articles published through September 2018, including 44 studies with a total of 123 subjects. Additionally, seven patients were incorporated through chart review of patients treated at Nationwide Children’s Hospital. RESULTS Analysis of 130 patients revealed a 3-year overall survival (OS) of 25%. Age at diagnosis had a significant impact on survival (p=0.0355); 3-year OS for infants < 18 months was 21%; 18–36 months was 26%; and > 36 months was 36%. Location of the primary tumor, metastatic stage and extent of surgical resection did not have significant impact on OS. On univariate analysis, XRT (p

Malignant transformation of CPP is rare and the mechanisms remain elusive. We report a case of progression of papilloma into carcinoma where we performed molecular sequencing of both samples. A boy was found to have a brain mass soon after birth. The gross total resection (GTR) was diagnostic of CPP. Six years later he developed a recurrent mass that demonstrated progression to a choroid plexus carcinoma (CPC). The patient received chemotherapy according to a “HeadStartII” protocol. He is 2.5 years off therapy and disease-free. A sequencing study consisting of 1700 genes and tumor transcriptome was done. The analysis of both samples revealed a germline variant of TP53(R248W) with LOH and an allele frequency of 39% in the germline sample, suggesting a mosaicism. Analysis of both samples identified extensive aneuploidy and similar pattern of gains in chromosomes 7/8/12/20/21/X. Copy number aberrations newly acquired in the carcinoma included copy gain of chromosomes 5q/12/15q/20, and copy loss of chromosomes 5q/13/22. The papilloma was found to harbor 3 somatic mutations with 4% to 21% allelic fractions, all lost in the carcinoma. These mutations were of unknown significance and with too low allelic fractions to be responsible for the transformation. More pertinently, chromosomal aneuploidy was significant with additional losses in the carcinoma. This resulted in the losses of two critical tumor suppressor genes, RB and BRCA2, playing a possible role in the observed transformation. The “HeadStart” experience suggested that the prognosis of TP53 mutant CPC may be improved in the absence of radiation therapy.

BACKGROUND Noonan syndrome (NS) is associated with germline Ras signaling pathway mutations, RAS overactivation and increased tumorigenesis risk. Rosette-forming glioneuronal tumors (RFGT) are rare indolent tumors. We report the molecular profiling of two patients with NS and RFGT. PATIENT 1: A 22-year-old male with NS was diagnosed with RFGT after partial tumor resection followed by focal irradiation. He was enrolled on a comprehensive genomic profiling study involving paired tumor-normal whole exome sequencing and RNA sequencing of the disease-involved tissue, revealing a germline PTPN11 alteration (p.Gly60Ala) consistent with NS, and a somatic deletion (p.Ile442_Thr454del) in PIK3R1 and a somatic variant (p.Lys656Glu) in FGFR1 with concomitant increased expression of PIK3R1 and FGFR1 by RNA-sequencing. The patient remains without tumor progression now nine months since irradiation. PATIENT 2: A 19-year-old male with persistent headaches, underwent a brain MRI demonstrated multiple abnormal signals in the pineal region and midbrain. He had a stereotactic biopsy revealing RFGT. He was enrolled on the genomic study revealing a germline PTPN11 alteration (p.Asn308Asp) resulting in a new diagnosis of NS. Several family members were subsequently identified with clinical features of NS, including his mother and two siblings, enabling appropriate counseling. Two somatic variants were found in trans in PIK3R1 (p.Thr454_Phe456del and p.Glu451_Asn453delinsAsp), and a somatic variant (p.Val695Met) in FGFR1, with resultant overexpression of PIK3R1. The patient is monitored with surveillance imaging. CONCLUSION We report the molecular profiling of two patients with NS and RFGT; strongly suggesting their connection to RASopathies through the overactivation of the MAPK and PI3K/AKT/mTOR signaling pathways.

Children with pediatric gliomas harboring BRAF V600E mutation have a poor outcome with current chemoradiation strategies. Our aim was to study the role of targeted BRAF inhibition in these tumors. We collected clinical, imaging, molecular and outcome information from BRAF V600E glioma patients treated with BRAFi across 29 centers from multiple countries. Sixty-seven patients were treated with BRAFi (56 pediatric low grade gliomas, PLGG and 11 pediatric high grade gliomas, PHGG) for up to 5.6 years. Objective responses were observed in 80% of PLGGs compared to 28% with conventional chemotherapy (p

We report an unusual case of a patient with primary CNS-HS a very rare neoplasm of histiocytic lineage with usually poor prognosis. An 8 year old boy presented with a one month history of headaches, nausea and vomiting. Physical examination revealed nystagmus and dysmetria. Brain MRI revealed a localized 2.4 cm posterior fossa (cerebellar) mass with restricted diffusion. The patient underwent a gross total resection of the mass. Initial post-operative lumbar puncture was positive for rare malignant cells. Pathology showed a focally necrotic neoplasm, composed of nests and cords of large relatively uniform cells with abundant eosinophilic cytoplasm, moderately pleomorphic nuclei and numerous mitotic figures, consistent with CNS-HS with juvenile xanthogranuloma phenotype, as supported by positive IHC expression of CD163, CD68, CD14, fascin, and Factor XIIIa, while negative for CD1a, Lymphoid and Myeloid markers, and BRAFv600e mutation. He was treated with two cycles of clofarabine and cytarabine and triple intrathecal (IT) chemotherapy. He developed generalized seizures and MRI showed demyelination consistent with IT methotrexate toxicity; MTX was then discontinued. He was then given two additional cycles of cladribine and weekly intrathecal therapy prior to consolidation with an Allo-HCT using a 10/10 HLA allelic-matched unrelated donor. His conditioning regimen included total body irradiation and cyclophosphamide. He did well post-transplant with peripheral blood chimerism at 1 year showing > 95% donor cells. He remains disease-free with an excellent quality of life since August 2016. We report one of the few known survivors of this unusual and highly malignant entity.

The currently active, prospective multi-center Head Start 4 (HS4) trial for CNS embryonal tumors differs from prior HS I-III trials by utilizing absolute phagocyte count (APC) as a measure of myeloid recovery instead of absolute neutrophil count. The aim of this study was to determine if utilization of APC resulted in unanticipated treatment-related toxicities during induction chemotherapy for patients enrolled on HS4. Review of the RedCap database was conducted for treatment-related CTCAE grade 3 and 4 toxicities. Data were summarized descriptively. Nonparametric statistical methods were used for comparisons. At the time of this most recent analysis, a total of 180 induction cycles were completed for the 57 patients enrolled. Of the 57 patients, nine voluntarily discontinued therapy after completing a median of three cycles each. These patients had a higher number of documented infections (59% versus 24%, p=0.0004). Veno-occlusive disease (VOD) occurred in five patients, three of whom voluntarily discontinued therapy. Since the protocol amendment utilizing milligram per kilogram dosing for patients less than six years of age, there have been no documented episodes of VOD. The overall toxicities for this cohort were comparable to those reported for induction chemotherapy in HS I-II trials. The toxic death rate is lower for HS4 compared to HS I-II (0.018% versus 4.7–6%) (Chi et al 2004). Other than the high rate of infection, possibly associated with shorter duration of the immediately prior cycles, the use of APC as part of a dose-compression strategy in HS4 does not appear associated with more significant toxicities.

Medulloblastoma is the most common malignant embryonal brain tumor in children with only modest improvements in outcomes achieved over the last 20 years. The implementation of irradiation-avoiding strategies, including trials by the “Head Start” consortium, have demonstrated improved cure rates along with enhanced quality of life. Simultaneously, the classification of medulloblastomas has undergone a dramatic shift as molecular testing has made it possible to divide these tumors into distinctive subtypes. Currently, the WHO recognizes four medulloblastoma molecular subgroups; however it remains unclear how patients within these subgroups respond to modern irradiation-avoiding therapies. This study aims to demonstrate the feasibility of prospective molecular profiling in medulloblastoma patients enrolled on the “Head Start 4” trial. Whole-exome sequencing (SureSelect Human All Exon V6+COSMIC) and DNA methylation (Illumina EPIC Array) profiling were performed on 10 paired tumor/blood samples and 4 tumor samples, respectively. High-quality mutational and copy number data were produced for each of the 10 subjects demonstrating well-described gene mutations (SUFU) and chromosomal losses (9q and 10q). Four subjects had methylation profiling which successfully separated them into the WHO subgroups (two SHH and two Group 3). These data showed the feasibility of prospective high-dimensional mutational and DNA methylation analysis using “Head Start 4” patients. Future work will focus on finalizing these profiling efforts, enabling the development of models that predict response to irradiation-avoiding treatment and, in general, a better understanding of the molecular mechanisms underlying treatment resistance and tumor progression, leading to more personalized approaches to treating children with medulloblastoma.

INTRODUCTION: Primary central nervous system (CNS) germ cell tumors (GCT) account for 2–3% of brain tumors in children/adolescents in Western hemisphere, being classified as germinomas and non-germinomatous GCT (NGGCT). Our objective is to report the results of a Brazilian CNSGCT consortium protocol. MATERIALS/METHODS: Since 2013, 28 patients with histologic and/or tumor marker (TM) diagnosis of germinoma with/without HCGβ levels ≤200mIU/ml (n=21) and NGGCT (n=7), received four/six cycles of carboplatin/etoposide/cyclophosphamide, followed by 18Gy ventricular field irradiation (VFI) and primary site(s) boost. Autologous bone marrow transplant (ABMT) was conducted for NGGCT low responders. RESULTS: Median age-13,5 years, 21 males. Diagnosis was made by TM (n=5), surgery (n=14), both (n=7). Two bifocal cases, TM(-) were treated as germinoma. Primary tumor location was pineal(n=14), suprasellar(n=7), bifocal (n=7). Nine had ventricular/spinal spread. Second-look surgery occurred in five patients. For the germinoma group, 18 patients achieved complete response (CR) after chemotherapy, the remaining 4 showed residual teratoma/scar. The NGGCT patients (n=7) showed partial responses(n=5), three with TM(-) and two CR after 4/6 cycles. Two patients were submitted to ABMT. Radiotherapy was performed as described except in two. No recurrences to date. One patient died of endocrinologic complications. Toxicity was mostly grade ¾ neutropenia/thrombocytopenia (NGGCT) following cyclophosphamide and in all patients for at least one cycle following carboplatin. At a median follow-up of 29,6 months, event-free and overall survival was 96,4%. CONCLUSION: Dose reduction of VFI to 18Gy seems to preserve efficacy. Further follow-up is warranted to better assess treatment efficacy especially among the slow responder patients.

Desmoplastic nodular medulloblastoma (DNMB) is among the most treatable pediatric brain tumors with overall survival often reported in the range of 80-90%. Recently, several attempts around the globe were initiated in order to scale back therapy with the hopes of reducing both the short and long term toxicities. Unfortunately, these efforts have not been successful to date, which is highlighted by the most recent early closure of the Children’s Oncology group trial, ACNS1221, due to increased incidence of progression. There is no consensus at this time regarding the best salvage regimen to use for patients who failed therapy on ACNS1221. Here we present two patients with DNMB who recurred after treatment on ACNS 1221 and were successfully salvaged with high dose chemotherapy and stem cell support at our institution. The first patient is a 3 years old male who recurred with metastatic disease within 3 months post-therapy. He was treated with a 5-drug regimen consisting of vincristine, cisplatin, etoposide, cyclophosphamide and high-dose methotrexate for 3 cycles with autologous tandem transplants and proton craniospinal irradiation therapy of 23.4Gy and a boost to the posterior fossa of 54 Gy and the spine to 45 Gy. The second patient is a 4 years old male with Gorlin Syndrome and Trisomy 21 who had local recurrence within 9 months from finishing therapy, and was salvaged with 3 cycles of carboplatin and thiotepa with autologous tandem stem cell support without the need for radiation therapy. Both patients are currently alive with no evidence of disease.

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.

BACKGROUND: Outcomes of patients with relapsed CNS NGGCTs are extremely poor compared to patients with relapsed germinomas. The rarity of these tumors and paucity of prospective clinical trials make it difficult to establish a standard treatment approach. METHODS: A review of clinical trials that included patients with relapsed CNS NGGCTs was performed. RESULTS: Seventy-four patients reported in one prospective clinical trial and three retrospective studies were identified; only 14 patients were reported as long-term survivors (19%). Of the 14 survivors, eight relapsed within 24 months of initial diagnosis; five of 14 survivors had elevated serum/ cerebrospinal fluid (CSF) alpha-fetoprotein (AFP) at primary diagnosis; none had elevated serum/CSF AFP at relapse. Of the 14 survivors, seven had elevated serum/CSF beta-human chorionic gonadotropin (HCGβ) at initial diagnosis or relapse. Eleven received radiotherapy at some time following relapse (craniospinal irradiation=9, focal radiotherapy=2). Twelve received high-dose chemotherapy (HDCx) followed by autologous hematopoietic cell rescue (AuHCR); of six with data, all achieved complete or continuing complete (two after surgical resection) remission (CR) prior to HDCx. Post-transplant, eleven out of twelve (one with stable disease) continued without residual or recurrent disease. CONCLUSION: Serum/ CSF AFP status at relapse, achieving CR prior and post-HDCx, receiving radiotherapy and HDC may have more prognostic value compared to the time of relapse, tumor markers at initial diagnosis and achieving GTR prior to consolidation therapy. Future trials need to better stratify relapsed patients on the basis of AFP status prior to relapse and receiving radiotherapy and HDCx.

BACKGROUND: The lack of a standard treatment approach has contributed to poor outcomes of patients with recurrent central nervous system (CNS) mixed malignant germ cell tumors (MMGCT). There are no data in the literature supporting optimal re-induction chemotherapy regimens that should be used for patients with recurrent CNS MMGCT. METHODS: A literature review was conducted to explore the response rate of patients with recurrent CNS MMGCT to different re-induction chemotherapy regimens by searching PubMed from 1985 through November 2017. Tumors were classified according to Japanese, European, and North American prognostic group classifications determined at initial presentation. RESULTS: Forty-two responses to various re-induction chemotherapy regimens reported in 38 patients were included. Two patients were inevaluable and their responses to re-induction chemotherapy were excluded. Thirty-five responses to various re-induction chemotherapy regimens were evaluable in 33 patients following a first relapse. Six (17%) responses were reported as complete or continuous complete responses, seven (20%) partial responses, two (6%) were stable disease, two (6%) were mixed responses, 18 (51%) were progressive disease. Five of ten patients treated without platinum-based chemotherapy experienced tumor progression. There was a trend towards a higher rate of tumor progression among histological poor prognostic group patients, and amongst patients relapsing within 24 months of initial diagnosis. CONCLUSION: The response rate of recurrent CNS MMGCT to re-induction chemotherapy may correlate with the initial prognostic grouping of the tumor and the time to relapse. However, further studies are needed to determine the optimal re-induction chemotherapy regimens for patients with recurrent MMGCT.

INTRODUCTION: The incidence of hepatotoxicity has never been reported for intensive induction chemotherapy regimens for young children with primary malignant CNS tumors. We report our comprehensive review of available data on patients enrolled on the Head Start II trial 1997-2003. METHODS: Retrospective chart review of patients enrolled on Head Start II (n=90); Patients with non-metastatic disease other than ATRT as the primary diagnosis (n=49) received Induction without HD-MTX. The rest received HD-MTX (age-based; 400mg/Kg or 12mg/m2); Peak serum ALT, AST and bilirubin were recorded for each cycle, as well as cycle days on which the peak levels were recorded. Additionally, all grade III/IV toxicities, including clinical sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) were documented. RESULTS: Forty-one patients received 156 Induction cycles including HD-MTX; 53 patients received 237 Induction cycles without HD-MTX. Among patients in whom test results were available, grades III/IV elevations in ALT, AST and bilirubin were recorded in 5%, 7% and 10% of HD-MTX containing cycles respectively, whereas in 3%, 0.5% and 1% of Induction cycles without HD-MTX. Timing of mean peak elevations of ALT, AST and bilirubin did not differ among patients receiving or not receiving HD-MTX Induction cycles. There were no documented reports of grades III/IV SOS/VOD. CONCLUSIONS: There were no permanent or severe hepatotoxicities reported during Induction chemotherapy; however, peak transaminases were higher for patients receiving HD-MTX. These data provide a baseline from which to evaluate hepatotoxicity and incidence of SOS/VOD in the current Head Start 4 trial in which all patients received HD-MTX during Induction.

PURPOSE: Prognosis for central nervous system (CNS) non-germinomatous germ cell tumor (NGGCT) patients that relapse during induction is poor. We present our experience for these patients. METHODS: Medical records of CNS NGGCT patients at Children’s Hospital Los Angeles between 2008 and 2014 were reviewed for clinical characteristics, treatment, and outcome. RESULTS: Eight (27.6%) of 29 patients relapsed or were refractory during induction chemotherapy, an average of 6.3 months from diagnosis. Five patients had pineal primaries and three patients had synchronous pineal and suprasellar tumors. All patients had tumor marker (TM) elevation in serum and/or CSF; four patients underwent biopsy. Three patients had local relapse, two local and ventricular, and three had TM-only relapse. All received re-induction chemotherapy with gemcitabine 800mg/m2, paclitaxel 170mg/m2, and oxaliplatin 100mg/m2 (GemPOx). After re-induction, the three TM-only relapses continued to have no evidence of disease (NED) radiographically, three patients showed a partial response (PR), and two patients had stable disease (SD). Seven patients received high-dose chemotherapy with a thiotepa-based regimen followed by autologous stem cell rescue (ASCR). After ASCR, radiographically, three TM positive cases continued to be NED, three had a PR, and one patient had SD. Six received additional irradiation post-transplant, of which five are alive. Six of eight relapsed/refractory patients are alive at 41, 42, 66, 71, 78, 79 months from initial diagnosis. CONCLUSIONS: Relapsed/refractory CNS NGGCT patients can be successfully salvaged by re-induction chemotherapy followed by consolidation with a thiotepa-based myeloablative regimen and re- irradiation.

Pediatric high-grade gliomas (pHGG) are aggressive malignant neoplasms representing approximately 20% of all pediatric central nervous system tumors. Current therapies offer limited disease control, and patients with recurrent disease have a particularly poor prognosis. While the empiric use of targeted therapy, especially at progression, is being increasingly practiced, there is a paucity of data regarding temporal and therapy-driven genomic evolution in pHGGs. To better understand the genetic landscape of pHGGs at recurrence, we performed whole exome, transcriptome and methylation analyses on pHGG matched primary and recurrent tumors from 16 patients, median age of 15 years (range: 4–29). Matched normal tissue, where available, was evaluated to determine mutation somatic status. Genetic mutational results suggested that our cohort could be segregated into 3 groups. Group 1 tumor pairs (n=6) carry driver mutations in histone 3 (H3F3A, HIST1H3B) or IDH1 that were retained between the primary tumor and recurrence. In tumors with H3F3A and IDH1 mutations, their obligate partner TP53 or ATRX mutations were also conserved. Group 2 tumor pairs (n=8) were histone 3 or IDH1 wild-type, but most harbored mutations in genes that are modifiers of histone or chromatin (KMT2D, ZMYND11, EP300, BCOR). TP53 and ATRX driver mutations were present in 50% (n=4) of tumors, and 25% (n=2) had a BRAF V600E mutation. Mutations in other putative drug targets (EGFR, ERBB2, PI3-kinase mutations) were not always shared between primary and recurrent tumors, indicating evolution during tumor progression. Group 3 samples (n=2) carried germline mutations in NF1. Mutational burden, gene ontology analysis and correlation with treatment exposure are ongoing. The finding that key driver mutations, some of which are targetable (e.g. IDH1, BRAF V600E) are conserved at recurrence, while other targetable mutations are acquired, indicates that re-biopsy at recurrence may provide better guidance for effective treatment of pHGG with targeted therapy.

Item does not contain fulltext Background.: Pineoblastoma is a rare pineal region brain tumor. Treatment strategies have reflected those for other malignant embryonal brain tumors. Patients and Methods.: Original prospective treatment and outcome data from international trial groups were pooled. Cox regression models were developed considering treatment elements as time-dependent covariates. Results.: Data on 135 patients with pineoblastoma aged 0.01-20.7 (median 4.9) years were analyzed. Median observation time was 7.3 years. Favorable prognostic factors were age >/=4 years (hazard ratio [HR] for progression-free survival [PFS] 0.270, P < .001) and administration of radiotherapy (HR for PFS 0.282, P < .001). Metastatic disease (HR for PFS 2.015, P = .006), but not postoperative residual tumor, was associated with unfavorable prognosis. In 57 patients /=4 years, PFS/OS were 72 +/- 7%/73 +/- 7% for patients without metastases, and 50 +/- 10%/55 +/- 10% with metastases. Seventy-three patients received radiotherapy (48 conventionally fractionated CSI, median dose 35.0 [18.0-45.0] Gy, 19 hyperfractionated CSI, 6 local radiotherapy), with (n = 68) or without (n = 6) chemotherapy. The treatment sequence had no impact; application of HDCT had weak impact on survival in older patients. Conclusion.: Survival is poor in young children treated without radiotherapy. In these patients, combination of HDCT and local radiotherapy may warrant further evaluation in the absence of more specific or targeted treatments. CSI combined with chemotherapy is effective for older non-metastatic patients.

BACKGROUND: Individuals with Trisomy 21 have a striking cancer distribution, with a 10- to 20- fold increased risk of acute leukemia compared to a markedly decreased incidence of solid tumors. Medulloblastoma, the most common malignant brain tumor of childhood, is particularly rare in the DS population, with only one published case. As demonstrated in a mouse model of DS, the supernumerary chromosome 21 is associated with cerebellar hypoplasia and a decreased number of external granule cell layer progenitor cells (EGLs). Treatment of these mice with sonic hedgehog (Shh) signaling pathway agonists promotes normalization of EGLs and improved cognitive functioning. PATIENT: We describe a 21 month-old male with DS with desmoplastic/nodular medulloblastoma (DNMB) - a tumor derived from Shh dysregulation and over-activation of EGLs. Immunohistochemistry revealed patchy cytoplasmic GAB-1 staining and patchy strong YAP-1 nuclear and cytoplasmic staining, further placing this DNMB into the new consensus molecular classification Shh subgroup. Additional testing revealed a de novo heterozygous germ line mutation in the PTCH1 gene encoding a tumor suppressor protein in the Shh pathway; both parents tested negative for this mutation. CONCLUSIONS: The reduced presence of EGLs in DS patients offers a plausible explanation for the disparity of medulloblastoma in this population. Conversely, patients with PTCH1 germ line mutations experience Shh pathway overstimulation resulting in Gorlin (Nevoid Basal Cell Carcinoma) Syndrome and an increased incidence of malignant transformation of EGLs leading to medulloblastoma formation. This represents the first documented report of an individual with DS (developmental failure of EGLs, decreased incidence of medulloblastoma) simultaneously carrying PTCH1 germ line mutation (overstimulated EGLs, increased incidence of medulloblastoma). Thus, we observe a highly unusual circumstance in which the PTCH1 mutation appears to ‘trump’ the effects of trisomy 21 in causation of Shh-activated medulloblastoma. Additional genomic studies are ongoing and will be presented.

PURPOSE: Bifocal presentation of central nervous system (CNS) germinomas, with synchronous pineal and suprasellar involvement, is common, and associated with favorable outcome. However, the incidence and outcome of bifocal presentation of non-germinomatous germ cell tumors (NGGCT) is less well described. METHODS: Medical records of patients with CNS NGGCT treated at Children's Hospital Los Angeles between 1993 and 2014 were reviewed for clinical characteristics, treatment and outcome. RESULTS: Seven (24.1%) of 29 patients diagnosed with CNS NGGCT between 1993 and 2014 had bifocal involvement. The mean age at diagnosis was 13.1 years (range: 8-22 years). Diagnosis was made on tumor marker elevation in seven patients, and confirmed on histopathology on one patient. Seven patients had elevated AFP and one patient had elevated βHCG in serum and/or CSF. Two patients are still undergoing therapy and have not been included in the survival analyses. Four of remaining five patients are long term survivors at 41, 56, 57, and 97 months. Patient #1 received initial chemotherapy without irradiation, relapsed in the 3rd ventricle at 10 months, and was successfully salvaged with high-dose chemotherapy (HDCx) with autologous hematopoietic stem cell rescue (AuHCR) and 3600cGy craniospinal irradiation (CSI) with local boost. Patient #2 had partial response to chemotherapy, underwent HDCx and AuHCR, followed by 3600cGy CSI with boost. Patients #3 and #4 received chemotherapy with a complete response, followed by whole ventricular irradiation with a local boost. Patient #5 received chemotherapy only, developed ventricular relapse at 75 months, was treated with cyclophosphamide and vinblastine followed by CSI with boost, but died at 87 months. CONCLUSIONS: Our experience suggests that bifocal NGGCT may be more common than previously thought, and may be more likely to have yolk-sac component given elevated AFP, and therefore have a better prognosis than other NGGCT.

BACKGROUND: Medulloblastomas in children can be categorized into four molecular subgroups with differing clinical characteristics such that subgroup determination aids in prognostication and risk-adaptive treatment strategies. Magnetic resonance spectroscopy (MRS) is a widely available, non-invasive tool used to determine metabolic characteristics of tumors providing diagnostic information without the need for tumor tissue. In this study we investigated the hypothesis that metabolite concentrations measured by MRS would differ between molecular subgroups of medulloblastoma allowing for accurate subgroup determination. METHODS: Magnetic resonance spectroscopy was used to measure metabolites in medulloblastomas across molecular subgroups (SHH = 12, Groups 3/4 = 17, WNT = 1). Levels of fourteen metabolites were analyzed to determine those which were most discriminant for medulloblastoma subgroups in order to construct a multivariable classifier to distinguish between combined Group 3/4 and SHH tumors. RESULTS: Medulloblastomas across molecular subgroups revealed distinct spectral features. A five metabolite subgroup classifier inclusive of creatine, myo-inositol, taurine, aspartate and lipid 13a was developed that could discriminate between Group 3/4 and SHH medulloblastomas with excellent accuracy (cross-validated Area Under the Curve AUC = 0.88). Group 3 and Group 4 tumors demonstrated metabolic profiles with readily detectable taurine, lower levels of lipids and high levels of creatine. SHH tumors showed prominent choline and lipid with low levels of creatine and little or no evidence of taurine. CONCLUSIONS: The data show that medulloblastomas of different molecular subgroups differ metabolically as measured using MRS. MRS is a potentially useful and accurate tool to determine medulloblastoma molecular subgroups.

Recurrent medulloblastoma is highly lethal in previously irradiated patients. Previously irradiated patients with M-0-M-3 recurrences who achieved a minimal disease state prior to protocol enrollment received carboplatin (Calvert formula with area under the curve = 7 mg/mL min, maximum 500 mg/m(2)/day) on days -8 to -6, and thiotepa (300 mg/m(2)/day) and etoposide (250 mg/m(2)/day) on days -5 to -3, followed by autologous stem cell rescue (ASCR) on day 0. Twenty-five patients, aged 7.6-44.7 years (median 13.8 years) at ASCR, were treated. Three (12%) died of treatment-related toxicities within 30 days of ASCR, due to multiorgan system failure (n = 2) and aspergillus infection with veno-occlusive disease (n = 1). Tumor recurred in 16 at a median of 8.5 months (range 2.3-58.5 months). Six are event-free survivors at a median of 151.2 months post-ASCR (range 127.2-201.6 months). The Kaplan-Meier estimate of median overall survival is 26.8 months (95% CI: 11.9-51.1 months) and of event-free survival (EFS) and overall survival are both 24% (95% CI: 9.8%-41.7%) at 10 years post-ASCR. M-0 (vs M-1 + ) recurrence prior to protocol, lack of tissue confirmation of relapse, and initial therapy of radiation therapy (RT) alone (vs RT + chemotherapy) were not significantly associated with better EFS (P = .33, .34, and .27, respectively). Trends toward better EFS were noted in patients (n = 5) who received additional RT as part of their retrieval therapy (P = .07) and whose recurrent disease was demonstrated to be sensitive to reinduction chemotherapy (P = .09). This retrieval strategy provides long-term EFS for some patients with previously irradiated recurrent medulloblastoma. The use of additional RT may be associated with better outcome.