Germline ERBB3 mutation in familial non-small-cell lung carcinoma: expanding ErbB's role in oncogenesis.

Lung cancer is the commonest cause of cancer deaths worldwide. Although strongly associated with smoking, predisposition to lung cancer is also heritable, with multiple common risk variants identified. Rarely, dominantly inherited non-small-cell lung cancer (NSCLC) has been reported due to somatic mutations in EGFR/ErbB1 and ERBB2. Germline exome sequencing was performed in a multi-generation family with autosomal dominant NSCLC, including an affected child. Tumour samples were also sequenced. Full-length wild-type (wtErbB3) and mutant ERBB3 (mutErbB3) constructs were transfected into HeLa cells. Protein expression, stability, and subcellular localization were assessed, and cellular proliferation, pAkt/Akt and pERK levels determined. A novel germline variant in ERBB3 (c.1946 T > G: p.Iso649Arg), coding for receptor tyrosine-protein kinase erbB-3 (ErbB3), was identified, with appropriate segregation. There was no loss-of-heterozygosity in tumour samples. Both wtErbB3 and mutErbB3 were stably expressed. MutErbB3-transfected cells demonstrated an increased ratio of the 80 kDa form (which enhances proliferation) compared with the full-length (180 kDa) form. MutErbB3 and wtErbB3 had similar punctate cytoplasmic localization pre- and post-epidermal growth factor stimulation; however, epidermal growth factor receptor (EGFR) levels decreased faster post-stimulation in mutErbB3-transfected cells, suggesting more rapid processing of the mutErbB3/EGFR heterodimer. Cellular proliferation was increased in mutErbB3-transfected cells compared with wtErbB3 transfection. MutErbB3-transfected cells also showed decreased pAkt/tAkt ratios and increased pERK/tERK 30 min post-stimulation compared with wtErbB3 transfection, demonstrating altered signalling pathway activation. Cumulatively, these results support this mutation as tumorogenic. This is the first reported family with a germline ERBB3 mutation causing heritable NSCLC, furthering understanding of the ErbB family pathway in oncogenesis.

Molecular classification and outcome of children with rare CNS embryonal tumors: results from St. Jude Children's Research Hospital including the multi-center SJYC07 and SJMB03 clinical trials.

Methylation profiling has radically transformed our understanding of tumors previously called central nervous system primitive neuro-ectodermal tumors (CNS-PNET). While this marks a momentous step toward defining key differences, reclassification has thrown treatment into disarray. To shed light on response to therapy and guide clinical decision-making, we report outcomes and molecular features of children with CNS-PNETs from two multi-center risk-adapted studies (SJMB03 for patients ≥ 3 years; SJYC07 for patients < 3 years) complemented by a non-protocol institutional cohort. Seventy patients who had a histological diagnosis of CNS-PNET or CNS embryonal tumor from one of the new categories that has supplanted CNS-PNET were included. This cohort was molecularly characterized by DNA methylation profiling (n = 70), whole-exome sequencing (n = 53), RNA sequencing (n = 20), and germline sequencing (n = 28). Clinical characteristics were detailed, and treatment was divided into craniospinal irradiation (CSI)-containing (SJMB03 and SJMB03-like) and CSI-sparing therapy (SJYC07 and SJYC07-like). When the cohort was analyzed in its entirety, no differences were observed in the 5-year survival rates even when CSI-containing therapy was compared to CSI-sparing therapy. However, when analyzed by DNA methylation molecular grouping, significant survival differences were observed, and treatment particulars provided suggestions of therapeutic response. Patients with CNS neuroblastoma with FOXR2 activation (CNS-NB-FOXR2) had a 5-year event-free survival (EFS)/overall survival (OS) of 66.7% ± 19.2%/83.3% ± 15.2%, and CIC rearranged sarcoma (CNS-SARC-CIC) had a 5-year EFS/OS both of 57.1% ± 18.7% with most receiving regimens that contained radiation (focal or CSI) and multidrug chemotherapy. Patients with high-grade neuroepithelial tumor with BCOR alteration (HGNET-BCOR) had abysmal responses to upfront chemotherapy-only regimens (5-year EFS = 0%), but survival extended with salvage radiation after progression [5-year OS = 53.6% ± 20.1%]. Patients with embryonal tumor with multilayered rosettes (ETMR) or high-grade glioma/glioblastoma multiforme (HGG/GBM) did not respond favorably to any modality (5-year EFS/OS = 10.7 ± 5.8%/17.9 ± 7.2%, and 10% ± 9.0%/10% ± 9.0%, respectively). As an accompaniment, we have assembled this data onto an interactive website to allow users to probe and query the cases. By reporting on a carefully matched clinical and molecular cohort, we provide the needed insight for future clinical management.

Physical ACTivity in Survivorship (PACTS): study protocol for a randomized controlled trial evaluating a goal-directed therapeutic exercise program in pediatric posterior fossa brain tumor survivors.

BACKGROUND: Posterior fossa brain tumors (PFBT) are the most common solid tumor in children. Recent increases in survival rates are encouraging; however, survivors may experience a plethora of disease- and treatment-related complications that can persist into adulthood. Therapeutic exercise interventions have been shown to improve quality of survivorship in other pediatric cancer diagnoses. There is also evidence that goal-directed interventions are effective at improving motor activities, function, and self-care in children with complex health conditions. Yet, there is currently no evidence on the efficacy of goal-directed therapeutic exercise in pediatric PFBT survivors. The Physical ACTivity in Survivorship (PACTS) study aims to investigate the effects of a novel goal-directed therapeutic exercise program on cardiorespiratory fitness and physical activity-related goal attainment in pediatric survivors of PFBT. METHOD: PFBT survivors, aged five to 17 years, who underwent surgery at least 12 months earlier and completed radiation therapy and/or chemotherapy at least 6 months prior will be recruited from the Queensland Children's Hospital (Brisbane, Australia) (target n = 48). Following baseline assessment, participants are randomized into either the intervention or usual care group. The intervention group will receive weekly individualized, goal-directed exercise therapy delivered face-to-face for 12 weeks, along with an accompanying home-based program (three sessions per week). Outcomes will be assessed at baseline, immediately post-intervention, and at 6- and 12-months post-intervention. The primary outcomes are cardiorespiratory fitness (Peak VO2) and physical activity-related goal attainment. Secondary outcomes are cardiorespiratory endurance, high-level mobility skills, functional muscle strength, habitual physical activity, gait, balance, quality of life, fatigue, participation, perceived movement skill competence and parameters of body composition. DISCUSSION: PACTS is the first study to investigate the efficacy of goal-directed therapeutic exercise in children with PFBT and provide evidence needed to inform clinical practice recommendations for managing quality of survivorship in PFBT survivors. TRIAL REGISTRATION: ACTRN12619000841178 .

Correction to: Risk-adapted therapy and biological heterogeneity in pineoblastoma: integrated clinico-pathological analysis from the prospective, multi-center SJMB03 and SJYC07 trials.

The original version of this article unfortunately contained a typesetting error in Fig 3c. The corrected Fig. 3 is given in the following page.

Risk-adapted therapy and biological heterogeneity in pineoblastoma: integrated clinico-pathological analysis from the prospective, multi-center SJMB03 and SJYC07 trials.

Pineoblastoma is a rare embryonal tumor of childhood that is conventionally treated with high-dose craniospinal irradiation (CSI). Multi-dimensional molecular evaluation of pineoblastoma and associated intertumoral heterogeneity is lacking. Herein, we report outcomes and molecular features of children with pineoblastoma from two multi-center, risk-adapted trials (SJMB03 for patients ≥ 3 years; SJYC07 for patients < 3 years) complemented by a non-protocol institutional cohort. The clinical cohort consisted of 58 patients with histologically diagnosed pineoblastoma (SJMB03 = 30, SJYC07 = 12, non-protocol = 16, including 12 managed with SJMB03-like therapy). The SJMB03 protocol comprised risk-adapted CSI (average-risk = 23.4 Gy, high-risk = 36 Gy) with radiation boost to the primary site and adjuvant chemotherapy. The SJYC07 protocol consisted of induction chemotherapy, consolidation with focal radiation (intermediate-risk) or chemotherapy (high-risk), and metronomic maintenance therapy. The molecular cohort comprised 43 pineal parenchymal tumors profiled by DNA methylation array (n = 43), whole-exome sequencing (n = 26), and RNA-sequencing (n = 16). Respective 5-year progression-free survival rates for patients with average-risk or high-risk disease on SJMB03 or SJMB03-like therapy were 100% and 56.5 ± 10.3% (P = 0.007); respective 2-year progression-free survival rates for those with intermediate-risk or high-risk disease on SJYC07 were 14.3 ± 13.2% and 0% (P = 0.375). Of patients with average-risk disease treated with SJMB03/SJMB03-like therapy, 17/18 survived without progression. DNA-methylation analysis revealed four clinically relevant pineoblastoma subgroups: PB-A, PB-B, PB-B-like, and PB-FOXR2. Pineoblastoma subgroups differed in age at diagnosis, propensity for metastasis, cytogenetics, and clinical outcomes. Alterations in the miRNA-processing pathway genes DICER1, DROSHA, and DGCR8 were recurrent and mutually exclusive in PB-B and PB-B-like subgroups; PB-FOXR2 samples universally overexpressed the FOXR2 proto-oncogene. Our findings suggest superior outcome amongst older children with average-risk pineoblastoma treated with reduced-dose CSI. The identification of biologically and clinically distinct pineoblastoma subgroups warrants consideration of future molecularly-driven treatment protocols for this rare pediatric brain tumor entity.

Correction to: International experience in the development of patient-derived xenograft models of diffuse intrinsic pontine glioma.

There are two errors and one omission in the original article. Author Gottardo's correct name is Nicholas G. Gottardo, author Hulleman's correct affiliation is no. 3 (VUMC, Amsterdam), and the Acknowledgements should include the following sentence: "We would like to thank Dr Angel Montero Carcaboso (Hospital Sant Joan de Deu, Barcelona, Spain) for generously supplying the HSJD-DIPG007 cells."

International experience in the development of patient-derived xenograft models of diffuse intrinsic pontine glioma.

PURPOSE: Diffuse intrinsic pontine glioma is the most aggressive form of high grade glioma in children with no effective therapies. There have been no improvements in survival in part due poor understanding of underlying biology, and lack of representative in vitro and in vivo models. Recently, it has been found feasible to use both biopsy and autopsy tumors to generate cultures and xenograft models. METHODS: To further model development, we evaluated the collective international experience from 8 collaborating centers to develop DIPG pre-clinical models from patient-derived autopsies and biopsies. Univariate and multivariate analysis was performed to determine key factors associated with the success of in vitro and in vivo PDX development. RESULTS: In vitro cultures were successfully established from 57% of samples (84.2% of biopsies and 38.2% of autopsies). Samples transferred in DMEM media were more likely to establish successful culture than those transported in Hibernate A. In vitro cultures were more successful from biopsies (84.2%) compared with autopsies (38.2%) and as monolayer on laminin-coated plates than as neurospheres. Primary cultures successfully established from autopsy samples were more likely to engraft in animal models than cultures established from biopsies (86.7% vs. 47.4%). Collectively, tumor engraftment was more successful when DIPG samples were directly implanted in mice (68%), rather than after culturing (40.7%). CONCLUSION: This multi-center study provides valuable information on the success rate of establishing patient-derived pre-clinical models of DIPG. The results can lead to further optimization of DIPG model development and ultimately assist in the investigation of new therapies for this aggressive pediatric brain tumor.

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.

Novel mutations target distinct subgroups of medulloblastoma.

Medulloblastoma is a malignant childhood brain tumour comprising four discrete subgroups. Here, to identify mutations that drive medulloblastoma, we sequenced the entire genomes of 37 tumours and matched normal blood. One-hundred and thirty-six genes harbouring somatic mutations in this discovery set were sequenced in an additional 56 medulloblastomas. Recurrent mutations were detected in 41 genes not yet implicated in medulloblastoma; several target distinct components of the epigenetic machinery in different disease subgroups, such as regulators of H3K27 and H3K4 trimethylation in subgroups 3 and 4 (for example, KDM6A and ZMYM3), and CTNNB1-associated chromatin re-modellers in WNT-subgroup tumours (for example, SMARCA4 and CREBBP). Modelling of mutations in mouse lower rhombic lip progenitors that generate WNT-subgroup tumours identified genes that maintain this cell lineage (DDX3X), as well as mutated genes that initiate (CDH1) or cooperate (PIK3CA) in tumorigenesis. These data provide important new insights into the pathogenesis of medulloblastoma subgroups and highlight targets for therapeutic development.

The international diffuse intrinsic pontine glioma registry: an infrastructure to accelerate collaborative research for an orphan disease.

Diffuse intrinsic pontine glioma (DIPG), a rare, often fatal childhood brain tumor, remains a major therapeutic challenge. In 2012, investigators, funded by the DIPG Collaborative (a philanthropic partnership among 29 private foundations), launched the International DIPG Registry (IDIPGR) to advance understanding of DIPG. Comprised of comprehensive deidentified but linked clinical, imaging, histopathological, and genomic repositories, the IDIPGR uses standardized case report forms for uniform data collection; serial imaging and histopathology are centrally reviewed by IDIPGR neuro-radiologists and neuro-pathologists, respectively. Tissue and genomic data, and cell cultures derived from autopsies coordinated by the IDIPGR are available to investigators for studies approved by the Scientific Advisory Committee. From April 2012 to December 2016, 670 patients diagnosed with DIPG have been enrolled from 55 participating institutions in the US, Canada, Australia and New Zealand. The radiology repository contains 3558 studies from 448 patients. The pathology repository contains tissue on 81 patients with another 98 samples available for submission. Fresh DIPG tissue from seven autopsies has been sent to investigators to develop primary cell cultures. The bioinformatics repository contains next-generation sequencing data on 66 tumors. Nine projects using data/tissue from the IDIPGR by 13 principle investigators from around the world are now underway. The IDIPGR, a successful alliance among philanthropic agencies and investigators, has developed and maintained a highly collaborative, hypothesis-driven research infrastructure for interdisciplinary and translational projects in DIPG to improve diagnosis, response assessment, treatment and outcome for patients.

Concordance between the chang and the International Society of Pediatric Oncology (SIOP) ototoxicity grading scales in patients treated with cisplatin for medulloblastoma.

BACKGROUND: Reporting ototoxicity is frequently complicated by use of various ototoxicity criteria. The International Society of Pediatric Oncology (SIOP) ototoxicity grading scale was recently proposed for standardized use in reporting hearing loss outcomes across institutions. The aim of this study was to evaluate the concordance between the Chang and SIOP ototoxicity grading scales. Differences between the two scales were identified and the implications these differences may have in the clinical setting were discussed. PROCEDURES: Audiological evaluations were reviewed for 379 patients with newly diagnosed medulloblastoma (ages 3-21 years). Each patient was enrolled on one of two St. Jude clinical protocols that included craniospinal radiation therapy and four courses of 75 mg/m(2) cisplatin chemotherapy. The latest audiogram conducted 5.5-24.5 months post-protocol treatment initiation was graded using the Chang and SIOP ototoxicity criteria. Clinically significant hearing loss was defined as Chang grade ≥2a and SIOP ≥2. Hearing loss was considered serious (requiring a hearing aid) at the level of Chang grade ≥2b and SIOP ≥3. RESULTS: A strong concordance was observed between the Chang and SIOP ototoxicity scales (Stuart's tau-c statistic = 0.89, 95% CI: 0.86, 0.91). Among those patients diagnosed with serious hearing loss, the two scales were in good agreement. However, the scales deviated from one another in classifying patients with less serious or no hearing loss. CONCLUSIONS: Although discrepancies between the Chang and SIOP ototoxicity scales exist primarily for patients with no or minimal hearing loss, the scales share a strong concordance overall.

Efficient detection and monitoring of pediatric brain malignancies with liquid biopsy based on patient-specific somatic mutation screening.

BACKGROUND: Brain cancer is the leading cause of cancer-related death in children. Early detection and serial monitoring are essential for better therapeutic outcomes. Liquid biopsy has recently emerged as a promising approach for detecting these tumors by screening body fluids for the presence of circulating tumor DNA (ctDNA). Here we tested the limits of liquid biopsy using patient-specific somatic mutations to detect and monitor primary and metastatic pediatric brain cancer. METHODS: Somatic mutations were identified in 3 ependymoma, 1 embryonal tumor with multilayered rosettes, 1 central nervous system neuroblastoma, and 7 medulloblastoma patients. The mutations were used as liquid biomarkers for serial assessment of cerebrospinal fluid (CSF) samples using a droplet digital PCR (ddPCR) system. The findings were correlated to the imaging data and clinical assessment to evaluate the utility of the approach for clinical translation. RESULTS: We developed personalized somatic mutation ddPCR assays which we show are highly specific, sensitive, and efficient in detection and monitoring of ctDNA, with a positive correlation between presence of ctDNA, disease course, and clinical outcomes in the majority of patients. CONCLUSIONS: We demonstrate the feasibility and clinical utility of personalized mutation-based liquid biopsy for the surveillance of brain cancer in children. However, even with this specific and sensitive approach, we identified some potential false negative analyses. Overall, our results indicate that changes in ctDNA profiles over time demonstrate the great potential of our specific approach for predicting tumor progression, burden, and response to treatment.

Nivolumab with or without ipilimumab in pediatric patients with high-grade CNS malignancies: Safety, efficacy, biomarker, and pharmacokinetics-CheckMate 908.

BACKGROUND: Therapeutic options are limited in pediatric CNS malignancies. CheckMate 908 (NCT03130959) is an open-label, sequential-arm, phase 1b/2 study investigating nivolumab (NIVO) and NIVO + ipilimumab (IPI) in pediatric patients with high-grade CNS malignancies. METHODS: Patients (N = 166) in 5 cohorts received NIVO 3 mg/kg every 2 weeks (Q2W) or NIVO 3 mg/kg + IPI 1 mg/kg every 3 weeks (4 doses) followed by NIVO 3 mg/kg Q2W. Primary endpoints included overall survival (OS; newly diagnosed diffuse intrinsic pontine glioma [DIPG]) and progression-free survival (PFS; other recurrent/progressive or relapsed/resistant CNS cohorts). Secondary endpoints included other efficacy metrics and safety. Exploratory endpoints included pharmacokinetics and biomarker analyses. RESULTS: As of January 13, 2021, median OS (80% CI) was 11.7 (10.3-16.5) and 10.8 (9.1-15.8) months with NIVO and NIVO + IPI, respectively, in newly diagnosed DIPG. Median PFS (80% CI) with NIVO and NIVO + IPI was 1.7 (1.4-2.7) and 1.3 (1.2-1.5) months, respectively, in recurrent/progressive high-grade glioma; 1.4 (1.2-1.4) and 2.8 (1.5-4.5) months in relapsed/resistant medulloblastoma; and 1.4 (1.4-2.6) and 4.6 (1.4-5.4) months in relapsed/resistant ependymoma. In patients with other recurrent/progressive CNS tumors, median PFS (95% CI) was 1.2 (1.1-1.3) and 1.6 (1.3-3.5) months, respectively. Grade 3/4 treatment-related adverse-event rates were 14.1% (NIVO) and 27.2% (NIVO + IPI). NIVO and IPI first-dose trough concentrations were lower in youngest and lowest-weight patients. Baseline tumor programmed death ligand 1 expression was not associated with survival. CONCLUSIONS: NIVO ± IPI did not demonstrate clinical benefit relative to historical data. The overall safety profiles were manageable with no new safety signals.

Implementation of DNA Methylation Array Profiling in Pediatric Central Nervous System Tumors: The AIM BRAIN Project: An Australian and New Zealand Children's Haematology/Oncology Group Study.

DNA methylation array profiling for classifying pediatric central nervous system (CNS) tumors is a valuable adjunct to histopathology. However, unbiased prospective and interlaboratory validation studies have been lacking. The AIM BRAIN diagnostic trial involving 11 pediatric cancer centers in Australia and New Zealand was designed to test the feasibility of routine clinical testing and ran in parallel with the Molecular Neuropathology 2.0 (MNP2.0) study at Deutsches Krebsforschungszentrum (German Cancer Research Center). CNS tumors from 269 pediatric patients were prospectively tested on Illumina EPIC arrays, including 104 cases co-enrolled on MNP2.0. Using MNP classifier versions 11b4 and 12.5, we report classifications with a probability score ≥0.90 in 176 of 265 (66.4%) and 213 of 269 (79.2%) cases, respectively. Significant diagnostic information was obtained in 130 of 176 (74%) for 11b4, and 12 of 174 (7%) classifications were discordant with histopathology. Cases prospectively co-enrolled on MNP2.0 gave concordant classifications (99%) and score thresholds (93%), demonstrating excellent test reproducibility and sensitivity. Overall, DNA methylation profiling is a robust single workflow technique with an acceptable diagnostic yield that is considerably enhanced by the extensive subgroup and copy number profile information generated by the platform. The platform has excellent test reproducibility and sensitivity and contributes significantly to CNS tumor diagnosis.

BRAF-mediated brain tumors in adults and children: A review and the Australian and New Zealand experience.

The mitogen-activated protein kinase (MAPK) pathway signaling pathway is one of the most commonly mutated pathways in human cancers. In particular, BRAF alterations result in constitutive activation of the rapidly accelerating fibrosarcoma-extracellular signal-regulated kinase-MAPK significant pathway, leading to cellular proliferation, survival, and dedifferentiation. The role of BRAF mutations in oncogenesis and tumorigenesis has spurred the development of targeted agents, which have been successful in treating many adult cancers. Despite advances in other cancer types, the morbidity and survival outcomes of patients with glioma have remained relatively stagnant. Recently, there has been recognition that MAPK dysregulation is almost universally present in paediatric and adult gliomas. These findings, accompanying broad molecular characterization of gliomas, has aided prognostication and offered opportunities for clinical trials testing targeted agents. The use of targeted therapies in this disease represents a paradigm shift, although the biochemical complexities has resulted in unexpected challenges in the development of effective BRAF inhibitors. Despite these challenges, there are promising data to support the use of BRAF inhibitors alone and in combination with MEK inhibitors for patients with both low-grade and high-grade glioma across age groups. Safety and efficacy data demonstrate that many of the toxicities of these targeted agents are tolerable while offering objective responses. Newer clinical trials will examine the use of these therapies in the upfront setting. Appropriate duration of therapy and durability of response remains unclear in the glioma patient cohort. Longitudinal efficacy and toxicity data are needed. Furthermore, access to these medications remains challenging outside of clinical trials in Australia and New Zealand. Compassionate access is limited, and advocacy for mechanism of action-based drug approval is ongoing.

Characteristics of children ≤36 months of age with DIPG: A report from the international DIPG registry.

BACKGROUND: Children ≤36 months with diffuse intrinsic pontine glioma (DIPG) have increased long-term survival (LTS, overall survival (OS) ≥24 months). Understanding distinguishing characteristics in this population is critical to improving outcomes. METHODS: Patients ≤36 months at diagnosis enrolled on the International DIPG Registry (IDIPGR) with central imaging confirmation were included. Presentation, clinical course, imaging, pathology and molecular findings were analyzed. RESULTS: Among 1183 patients in IDIPGR, 40 were eligible (median age: 29 months). Median OS was 15 months. Twelve patients (30%) were LTS, 3 (7.5%) very long-term survivors ≥5 years. Among 8 untreated patients, median OS was 2 months. Patients enrolled in the registry but excluded from our study by central radiology review or tissue diagnosis had median OS of 7 months. All but 1 LTS received radiation. Among 32 treated patients, 1-, 2-, 3-, and 5-year OS rates were 68.8%, 31.2%, 15.6% and 12.5%, respectively. LTS had longer duration of presenting symptoms (P = .018). No imaging features were predictive of outcome. Tissue and genomic data were available in 18 (45%) and 10 patients, respectively. Among 9 with known H3K27M status, 6 had a mutation. CONCLUSIONS: Children ≤36 months demonstrated significantly more LTS, with an improved median OS of 15 months; 92% of LTS received radiation. Median OS in untreated children was 2 months, compared to 17 months for treated children. LTS had longer duration of symptoms. Excluded patients demonstrated a lower OS, contradicting the hypothesis that children ≤36 months with DIPG show improved outcomes due to misdiagnosis.

Accuracy of central neuro-imaging review of DIPG compared with histopathology in the International DIPG Registry.

BACKGROUND: Diffuse intrinsic pontine glioma (DIPG) remains a clinico-radiologic diagnosis without routine tissue acquisition. Reliable imaging distinction between DIPG and other pontine tumors with potentially more favorable prognoses and treatment considerations is essential. METHODS: Cases submitted to the International DIPG registry (IDIPGR) with histopathologic and/or radiologic data were analyzed. Central imaging review was performed on diagnostic brain MRIs (if available) by two neuro-radiologists. Imaging features suggestive of alternative diagnoses included nonpontine origin, <50% pontine involvement, focally exophytic morphology, sharply defined margins, and/or marked diffusion restriction throughout. RESULTS: Among 286 patients with pathology from biopsy and/or autopsy, 23 (8%) had histologic diagnoses inconsistent with DIPG, most commonly nondiffuse low-grade gliomas and embryonal tumors. Among 569 patients with centrally-reviewed diagnostic MRIs, 40 (7%) were classified as non-DIPG, alternative diagnosis suspected. The combined analysis included 151 patients with both histopathology and centrally-reviewed MRI. Of 77 patients with imaging classified as characteristic of DIPG, 76 (99%) had histopathologic diagnoses consistent with DIPG (infiltrating grade II-IV gliomas). Of 57 patients classified as likely DIPG with some unusual imaging features, 55 (96%) had histopathologic diagnoses consistent with DIPG. Of 17 patients with imaging features suggestive of an alternative diagnosis, eight (47%) had histopathologic diagnoses inconsistent with DIPG (remaining patients were excluded due to nonpontine tumor origin). Association between central neuro-imaging review impression and histopathology was significant (p < 0.001), and central neuro-imaging impression was prognostic of overall survival. CONCLUSIONS: The accuracy and important role of central neuro-imaging review in confirming the diagnosis of DIPG is demonstrated.

Characteristics of patients ≥10 years of age with diffuse intrinsic pontine glioma: a report from the International DIPG/DMG Registry.

BACKGROUND: Diffuse intrinsic pontine gliomas (DIPG) generally occur in young school-age children, although can occur in adolescents and young adults. The purpose of this study was to describe clinical, radiological, pathologic, and molecular characteristics in patients ≥10 years of age with DIPG enrolled in the International DIPG Registry (IDIPGR). METHODS: Patients ≥10 years of age at diagnosis enrolled in the IDIPGR with imaging confirmed DIPG diagnosis were included. The primary outcome was overall survival (OS) categorized as long-term survivors (LTS) (≥24 months) or short-term survivors (STS) (<24 months). RESULTS: Among 1010 patients, 208 (21%) were ≥10 years of age at diagnosis; 152 were eligible with a median age of 12 years (range 10-26.8). Median OS was 13 (2-82) months. The 1-, 3-, and 5-year OS was 59.2%, 5.3%, and 3.3%, respectively. The 18/152 (11.8%) LTS were more likely to be older (P < .01) and present with longer symptom duration (P < .01). Biopsy and/or autopsy were performed in 50 (33%) patients; 77%, 61%, 33%, and 6% of patients tested had H3K27M (H3F3A or HIST1H3B), TP53, ATRX, and ACVR1 mutations/genome alterations, respectively. Two of 18 patients with IDH1 testing were IDH1-mutant and 1 was a LTS. The presence or absence of H3 alterations did not affect survival. CONCLUSION: Patients ≥10 years old with DIPG have a median survival of 13 months. LTS present with longer symptom duration and are likely to be older at presentation compared to STS. ATRX mutation rates were higher in this population than the general DIPG population.

Outcome and molecular analysis of young children with choroid plexus carcinoma treated with non-myeloablative therapy: results from the SJYC07 trial.

BACKGROUND: Choroid plexus carcinoma (CPC) is a rare and aggressive tumor of infancy without a clear treatment strategy. This study describes the outcomes of children with CPC treated on the multi-institutional phase 2 SJYC07 trial and reports on the significance of clinical and molecular characteristics. METHODS: Eligible children <3 years-old with CPC were postoperatively stratified to intermediate-risk (IR) stratum if disease was localized or high-risk (HR) stratum, if metastatic. All received high-dose methotrexate-containing induction chemotherapy. IR-stratum patients received focal irradiation as consolidation whereas HR-stratum patients received additional chemotherapy. Consolidation was followed by oral antiangiogenic maintenance regimen. Survival rates and potential prognostic factors were analyzed. RESULTS: Thirteen patients (median age: 1.41 years, range: 0.21-2.93) were enrolled; 5 IR, 8 HR. Gross-total resection or near-total resection was achieved in ten patients and subtotal resection in 3. Seven patients had TP53-mutant tumors, including 4 who were germline carriers. Five patients experienced progression and died of disease; 8 (including 5 HR) are alive without progression. The 5-year progression-free survival (PFS) and overall survival rates were 61.5 ± 13.5% and 68.4 ± 13.1%. Patients with TP53-wild-type tumors had a 5-year PFS of 100% as compared to 28.6 ± 17.1% for TP53-mutant tumors (P = .012). Extent of resection, metastatic status, and use of radiation therapy were not significantly associated with survival. CONCLUSIONS: Non-myeloablative high-dose methotrexate-containing therapy with maximal surgical resection resulted in long-term PFS in more than half of patients with CPC. TP53-mutational status was the only significant prognostic variable and should form the basis of risk-stratification in future trials.

Serial assessment of measurable residual disease in medulloblastoma liquid biopsies.

Nearly one-third of children with medulloblastoma, a malignant embryonal tumor of the cerebellum, succumb to their disease. Conventional response monitoring by imaging and cerebrospinal fluid (CSF) cytology remains challenging, and a marker for measurable residual disease (MRD) is lacking. Here, we show the clinical utility of CSF-derived cell-free DNA (cfDNA) as a biomarker of MRD in serial samples collected from children with medulloblastoma (123 patients, 476 samples) enrolled on a prospective trial. Using low-coverage whole-genome sequencing, tumor-associated copy-number variations in CSF-derived cfDNA are investigated as an MRD surrogate. MRD is detected at baseline in 85% and 54% of patients with metastatic and localized disease, respectively. The number of MRD-positive patients declines with therapy, yet those with persistent MRD have significantly higher risk of progression. Importantly, MRD detection precedes radiographic progression in half who relapse. Our findings advocate for the prospective assessment of CSF-derived liquid biopsies in future trials for medulloblastoma.