ABSTRACT
PURPOSE: The use of trametinib in the treatment of pediatric low-grade gliomas (PLGG) and plexiform neurofibroma (PN) is being investigated in an ongoing multicenter phase II trial (NCT03363217). Preliminary data shows potential benefits with significant response in the majority of PLGG and PN and an overall good tolerance. Moreover, possible benefits of MEK inhibitor therapy on cognitive functioning in neurofibromatosis type 1 (NF1) were recently shown which supports the need for further evaluation. METHODS: Thirty-six patients with NF1 (age range 3-19 years) enrolled in the phase II study of trametinib underwent a neurocognitive assessment at inclusion and at completion of the 72-week treatment. Age-appropriate Wechsler Intelligence Scales and the Trail Making Test (for children over 8 years old) were administered at each assessment. Paired t-tests and Reliable Change Index (RCI) analyses were performed to investigate change in neurocognitive outcomes. Regression analyses were used to investigate the contribution of age and baseline score in the prediction of change. RESULTS: Stable performance on neurocognitive tests was revealed at a group-level using paired t-tests. Clinically significant improvements were however found on specific indexes of the Wechsler intelligence scales and Trail Making Test, using RCI analyses. No significant impact of age on cognitive change was evidenced. However, lower initial cognitive performance was associated with increased odds of presenting clinically significant improvements on neurocognitive outcomes. CONCLUSION: These preliminary results show a potential positive effect of trametinib on cognition in patients with NF1. We observed significant improvements in processing speed, visuo-motor and verbal abilities. This study demonstrates the importance of including neuropsychological evaluations into clinical trial when using MEK inhibitors for patients with NF1.
Subject(s)
Neurofibromatosis 1 , Neuropsychological Tests , Pyridones , Pyrimidinones , Humans , Pyridones/therapeutic use , Pyrimidinones/therapeutic use , Pyrimidinones/pharmacology , Pyrimidinones/administration & dosage , Male , Female , Adolescent , Child , Neurofibromatosis 1/drug therapy , Neurofibromatosis 1/complications , Neurofibromatosis 1/psychology , Young Adult , Child, Preschool , Glioma/drug therapy , Glioma/psychology , Glioma/complications , Brain Neoplasms/drug therapy , Brain Neoplasms/psychology , Brain Neoplasms/complications , Adult , Protein Kinase Inhibitors/therapeutic use , Antineoplastic Agents/adverse effectsABSTRACT
BACKGROUND: Hepatitis C virus (HCV) infection is a significant global health burden, particularly among people who inject drugs. Rapid point-of-care HCV testing has emerged as a promising approach to improve HCV detection and linkage to care in harm reduction organizations such as needle and syringe programs. The objective of this study was to use an intersectionality lens to explore the barriers and enablers to point-of-care HCV testing in a needle and syringe program. METHODS: A qualitative study was conducted using semi-structured interviews with clients (people who inject drugs) and service providers in a large community organization focused on the prevention of sexually transmitted and blood borne infections and harm reduction in Montreal, Canada. An intersectionality lens was used alongside the Theoretical Domains Framework to guide the formulation of research questions as well as data collection, analysis, and interpretation. RESULTS: We interviewed 27 participants (15 clients, 12 providers). For clients, four themes emerged: (1) understanding and perceptions of HCV testing, (2) the role of an accessible and inclusive environment, (3) the interplay of emotions and motivations in decision-making, and (4) the impact of intersectional stigma related to HCV, behaviors, and identities. For providers, five themes emerged: (1) knowledge, skills, and confidence for HCV testing, (2) professional roles and their intersection with identity and lived experience, (3) resources and integration of services, (4) social and emotional factors, and (5) behavioral regulation and incentives for HCV testing. Intersectional stigma amplified access, emotional and informational barriers to HCV care for clients. In contrast, identity and lived experience acted as powerful enablers for providers in the provision of HCV care. CONCLUSION: The application of an intersectionality lens provides a nuanced understanding of multilevel barriers and enablers to point-of-care HCV testing. Findings underscore the need for tailored strategies that address stigma, improve provider roles and communication, and foster an inclusive environment for equitable HCV care. Using an intersectionality lens in implementation research can offer valuable insights, guiding the design of equity-focused implementation strategies.
Subject(s)
Hepatitis C , Point-of-Care Testing , Qualitative Research , Substance Abuse, Intravenous , Humans , Hepatitis C/psychology , Female , Male , Substance Abuse, Intravenous/psychology , Substance Abuse, Intravenous/complications , Adult , Middle Aged , Needle-Exchange Programs , Health Services Accessibility , Canada , Health Personnel/psychology , Interviews as Topic , Harm Reduction , Social StigmaABSTRACT
Pediatric gliomas, consisting of both pediatric low-grade (pLGG) and high-grade gliomas (pHGG), are the most frequently occurring brain tumors in children. Over the last decade, several milestone advancements in treatments have been achieved as a result of stronger understanding of the molecular biology behind these tumors. This review provides an overview of pLGG and pHGG highlighting their clinical presentation, molecular characteristics, and latest advancements in therapeutic treatments. Conclusion: The increasing understanding of the molecular biology characterizing pediatric low and high grade gliomas has revolutionized treatment options for these patients, especially in pLGG. The implementation of next generation sequencing techniques for these tumors is crucial in obtaining less toxic and more efficacious treatments. What is Known: ⢠Pediatric Gliomas are the most common brain tumour in children. They are responsible for significant morbidity and mortality in this population. What is New: ⢠Over the last two decades, there has been a significant increase in our global understanding of the molecular background of pediatric low and high grade gliomas. ⢠The implementation of next generation sequencing techniques for these tumors is crucial in obtaining less toxic and more efficacious treatments, with the ultimate goal of improving both the survival and the quality of life of these patients.
Subject(s)
Brain Neoplasms , Glioma , Precision Medicine , Humans , Glioma/genetics , Glioma/therapy , Child , Brain Neoplasms/genetics , Brain Neoplasms/therapy , Precision Medicine/methods , High-Throughput Nucleotide Sequencing/methods , Neoplasm GradingABSTRACT
BACKGROUND: Pediatric low-grade gliomas (PLGG) are the most frequent brain tumors in children. Up to 50% will be refractory to conventional chemotherapy. It is now known that the majority of PLGG have activation of the MAPK/ERK pathway. The same pathway is also activated in plexiform neurofibromas (PNs) which are low-grade tumors involving peripheral nerves in patients with neurofibromatosis type 1 (NF1). These lesions are known to be refractory to chemotherapy. Specific MEK inhibitors such as trametinib are now available and have been approved for other cancers harboring mutations in the MAPK/ERK pathway such as melanoma. We have observed significant responses to trametinib in patients with refractory PLGG in our institutions and results from the phase I study are promising. The treatment appears not only efficacious but is also usually well tolerated. We hypothesize that we will observe responses in the majority of refractory PLGG and PN treated with trametinib in this phase 2 study. METHODS: The primary objective is to determine the objective response rate of trametinib as a single agent for treatment of progressing/refractory tumors with MAPK/ERK pathway activation. The TRAM-01 study is a phase II multicentric open-label basket trial including four groups. Group 1 includes NF1 patients with progressing/refractory glioma. Group 2 includes NF1 patients with plexiform neurofibroma. Group 3 includes patients with progressing/refractory glioma with KIAA1549-BRAF fusion. Group 4 includes other patients with progressing/refractory glioma with activation of the MAPK/ERK pathway. Eligible patients for a given study group will receive daily oral trametinib at full dose for a total of 18 cycles of 28 days. A total of 150 patients will be enrolled in seven Canadian centers. Secondary objectives include the assessment of progression-free survival, overall survival, safety and tolerability of trametinib, serum levels of trametinib and evaluation of quality of life during treatment. DISCUSSION: Trametinib will allow us to target directly and specifically the MAPK/ERK pathway. We expect to observe a significant response in most patients. Following our study, trametinib could be integrated into standard treatment of PLGG and PN. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03363217 December 6, 2017.
Subject(s)
Glioma/drug therapy , MAP Kinase Signaling System/drug effects , Neurofibroma, Plexiform/drug therapy , Pyridones/therapeutic use , Pyrimidinones/therapeutic use , Adolescent , Antineoplastic Agents/therapeutic use , Canada , Child , Child, Preschool , Glioma/metabolism , Humans , Infant , Neurofibroma, Plexiform/metabolism , Protein Kinase Inhibitors/therapeutic use , Treatment Outcome , Young AdultABSTRACT
INTRODUCTION: Pediatric pilocytic astrocytomas (PAs) are low grade gliomas and the most common brain tumors in children. They often represent a therapeutic challenge when incompletely resected as they can recur and progress despite the use of several lines of chemotherapeutic agents or even radiation therapy. Genetic alterations leading to activation of the mitogen-activated-protein-kinase pathway are a hallmark of this disease and offer an interesting therapeutic alternative through the use of targeted inhibitors. METHODS: Here, we describe six children with sporadic PA who were treated with trametinib, a MEK inhibitor, following progression under conventional therapies. Retrospective chart review was performed. RESULTS: The median age at diagnosis was 2.3 years (y) old [range 11 months (m)-8.5 y old]. KIAA1549-BRAF fusion was identified in five cases, and hotspot FGFR1/NF1/PTPN11 mutations in one. All patients received at least one previous line of chemotherapy (range 1-4). The median time on treatment was 11 m (range 4-20). Overall, we observed two partial responses and three minor responses as best response; three of these patients are still on therapy. Treatment was discontinued in the patient with progressive disease. The most frequent toxicities were minor to moderately severe skin rash and gastro-intestinal symptoms. Two patients had dose reduction due to skin toxicity. Quality of life was excellent with decreased hospital visits and a close to normal life. CONCLUSION: Trametinib appears to be a suitable option for refractory pediatric low-grade glioma and warrants further investigations in case of progression.
Subject(s)
Antineoplastic Agents/therapeutic use , Astrocytoma/drug therapy , Brain Neoplasms/drug therapy , Pyridones/therapeutic use , Pyrimidinones/therapeutic use , Antineoplastic Agents/adverse effects , Astrocytoma/diagnostic imaging , Astrocytoma/genetics , Astrocytoma/physiopathology , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/genetics , Brain Neoplasms/physiopathology , Child , Child, Preschool , Disease Progression , Female , Humans , Infant , Male , Protein Kinase Inhibitors/therapeutic use , Pyridones/adverse effects , Pyrimidinones/adverse effects , Retreatment , Retrospective StudiesABSTRACT
This report describes a 6-year-old boy with disseminated low-grade astrocytoma and ventriculo-peritoneal shunt, who developed recurrent ascites while receiving sorafenib on a clinical trial. Laboratory analysis of the peritoneal fluid showed no elevation of protein content and no evidence of underlying infection or tumor dissemination. This report highlights ascites as a previously unrecognized adverse reaction to sorafenib in a patient with a ventriculo-peritoneal shunt. We conclude that such patients should be closely monitored for this complication when treated with sorafenib.
Subject(s)
Ascites/chemically induced , Astrocytoma/drug therapy , Brain Neoplasms/drug therapy , Niacinamide/analogs & derivatives , Phenylurea Compounds/adverse effects , Ventriculoperitoneal Shunt/adverse effects , Ascites/pathology , Child , Humans , Magnetic Resonance Imaging , Male , Niacinamide/adverse effects , Protein Kinase Inhibitors/administration & dosage , Recurrence , SorafenibABSTRACT
Background: The treatment of BRAF V600E gliomas with BRAF inhibitors (BRAFis) and MEK inhibitors (MEKis) has been increasingly integrated into clinical practice for pediatric low-grade gliomas (PLGGs) and pediatric high-grade gliomas (HGGs). However, some questions remain unanswered, such as the best time to start targeted therapy, duration of treatment, and discontinuation of therapy. Given that no clinical trial has been able to address these critical questions, we developed a Canadian Consensus statement for the treatment of BRAF V600E mutated pediatric as well as adolescent and young adult (AYA) gliomas. Methods: Canadian neuro-oncologists were invited to participate in the development of this consensus. The consensus was discussed during monthly web-based national meetings, and the algorithms were revised until a consensus was achieved. Results: A total of 26 participants were involved in the development of the algorithms. Two treatment algorithms are proposed, one for the initiation of treatment and one for the discontinuation of treatment. We suggest that most patients with BRAF V600E gliomas should be treated with BRAFis ± MEKis upfront. Discontinuation of treatment can be considered in certain circumstances, and we suggest a slow wean. Conclusions: Based on expert consensus in Canada, we developed algorithms for treatment initiation of children and AYA with BRAF V600E gliomas as well as a discontinuation algorithm.
Subject(s)
Consensus , Glioma , Mutation , Proto-Oncogene Proteins B-raf , Adolescent , Child , Female , Humans , Male , Young Adult , Brain Neoplasms/genetics , Brain Neoplasms/drug therapy , Canada , Glioma/genetics , Glioma/drug therapy , Protein Kinase Inhibitors/therapeutic use , Proto-Oncogene Proteins B-raf/geneticsABSTRACT
BACKGROUND: There is increasing reliance on oncoprotein assays such as the ß-subunit of human chorionic gonadotropin (ß-hCG) and alpha-fetoprotein (AFP) for diagnosis or confirmation of histology of central nervous system (CNS) germ cell tumors (GCT), but the relative diagnostic sensitivity and reliability of assays from serum (S), lumbar (L), and ventricular (V) cerebrospinal fluid (CSF) are uncertain. PROCEDURE: A total of 86 patients with CNS GCT were identified from our database. Fourteen patients had contemporaneous ß-hCG and/or AFP measurements from serum, ventricular, and lumbar CSF at diagnosis (n = 13) or relapse (n = 1), constituting the subjects for this report. Their primary tumor sites were: pineal (n = 8), suprasellar (n = 1), or both (n = 5). Their mean age at diagnosis was 16.0 years (range 9.1-25.9). The male:female sex ratio was 13:1. RESULTS: For the germinoma-treated patients (n = 8), the median (range) ß-hCG values (S, V, L) were 0 (0-6.9), 7.0 (0-57.4), 8.3 (0-34.0) mIU/ml. For patients managed as mixed malignant GCT (MMGCT) (n = 6), the median (range) ß-hCG values (S, V, L) were 3.9 (0-58.0), 3.6 (0-147.0), 61.8 (0-358.0) mIU/ml. The median (range) AFP values were 7.5 (0-27,400.0), 2.0 (0-2,981.0), 3.0 (0-14,015.0) ng/ml. Lumbar CSF ß-hCG values were equal or greater than those in ventricular CSF or serum in 12 of 13 cases (92.3%). All patients with MMGCT had lumbar AFP equal or greater than the ventricular CSF values, while serum AFP values remained highest. CONCLUSIONS: Ventricular CSF values cannot be considered a replacement for lumbar CSF. Lumbar CSF is the most reliable source of tumor markers to establish baseline and follow-up diagnostic endpoints.
Subject(s)
Biomarkers/cerebrospinal fluid , Central Nervous System Neoplasms/cerebrospinal fluid , Chorionic Gonadotropin, beta Subunit, Human/cerebrospinal fluid , Germinoma/cerebrospinal fluid , Germinoma/chemistry , alpha-Fetoproteins/cerebrospinal fluid , Adolescent , Adult , Central Nervous System Neoplasms/blood , Child , Chorionic Gonadotropin, beta Subunit, Human/blood , Female , Follow-Up Studies , Germinoma/blood , Humans , Male , Retrospective StudiesABSTRACT
Introduction: Rare neurodevelopmental disorders, including inherited white matter disorders or leukodystrophies, often present a diagnostic challenge on a genetic level given the large number of causal genes associated with a range of disease subtypes. This study aims to demonstrate the challenges and lessons learned in the genetic investigations of leukodystrophies through presentation of a series of cases solved using exome or genome sequencing. Methods: Each of the six patients had a leukodystrophy associated with hypomyelination or delayed myelination on MRI, and inconclusive clinical diagnostic genetic testing results. We performed next generation sequencing (case-based exome or genome sequencing) to further investigate the genetic cause of disease. Results: Following different lines of investigation, molecular diagnoses were obtained for each case, with patients harboring pathogenic variants in a range of genes including TMEM106B, GJA1, AGA, POLR3A, and TUBB4A. We describe the lessons learned in reaching the genetic diagnosis, including the importance of (a) utilizing proper multi-gene panels in clinical testing, (b) assessing the reliability of biochemical assays in supporting diagnoses, and (c) understanding the limitations of exome sequencing methods in regard to CNV detection and region coverage in GC-rich areas. Discussion: This study illustrates the importance of applying a collaborative diagnostic approach by combining detailed phenotyping data and metabolic results from the clinical environment with advanced next generation sequencing analysis techniques from the research environment to increase the diagnostic yield in patients with genetically unresolved leukodystrophies.
ABSTRACT
The COVID-19 pandemic triggered unprecedented expansion of telemedicine, including in the delivery of opioid agonist treatment (OAT) for people with opioid use disorder (OUD). However, many people with OUD lack the technological resources necessary for remote care, have complex needs, and are underserved, with precarious access to mainstream services. To address the needs of these individuals, we devised a unique program to deliver OAT via telemedicine with the support of community outreach workers in Montreal (Quebec, Canada). The program was co-constructed by the service de médecine des toxicomanies of the Centre hospitalier de l'Université de Montréal (CHUM-SMT)-a hospital-based addiction medicine service-and CACTUS Montréal-a community-based harm reduction organization known and trusted by its clientele. All procedures were jointly developed to enable flexible and rapid appointment scheduling. CACTUS Montréal workers promoted the program, facilitated private on-site telemedicine connections to the CHUM-SMT, accompanied patients during web-based appointments if requested, and provided ongoing holistic support and follow-up. The CHUM-SMT offered individualized OAT regimens and other health services as needed. Overall, our experience as clinicians and community-based workers intimately involved in establishing and running this initiative suggests that participants found it to be convenient, nonjudgmental, and responsive to their needs, and that the implication of CACTUS Montréal was highly valued and integral to patient engagement and retention. Beyond the context of the COVID-19 pandemic, similar programs may present a flexible and accessible means to deliver alternative treatment options for people with OUD disengaged from traditional care, bridge gaps between communities and health providers, and improve access to care in rural or remote settings.
Subject(s)
COVID-19 , Opioid-Related Disorders , Telemedicine , Humans , Pandemics , Opiate Substitution Treatment/methods , Community Health Services , Telemedicine/methods , Opioid-Related Disorders/epidemiology , Opioid-Related Disorders/drug therapyABSTRACT
The virulence of Streptomyces scabiei, the causal agent of common scab, depends mainly on the production of the toxin thaxtomin A. S. scabiei also produces indole-3-acetic acid (IAA) but the role of this hormone in the interaction between pathogenic streptomycetes and plants has not yet been elucidated. Tryptophan is a biosynthetic precursor of both IAA and thaxtomin A. In this study, the effect of tryptophan on thaxtomin A and IAA production as well as its effect on the transcription of the corresponding biosynthetic genes in S. scabiei has been analyzed. In vitro IAA production depended on the availability of tryptophan. However, addition of this amino acid to the culture medium inhibited the biosynthesis of thaxtomin A. Expression of thaxtomin A biosynthetic genes nos and txtA were strongly repressed in the presence of tryptophan; however, modulation of the expression was not observed for the IAA biosynthetic genes iaaM and iaaH. The effects of an exogenous tryptophan supply on S. scabiei virulence were assessed on radish seedlings. Addition of tryptophan reduced symptoms on inoculated radish roots compared with seedlings grown in the absence of the bacterium, by way of inhibition of thaxtomin A production and increase of IAA biosynthesis.
Subject(s)
Indoleacetic Acids/metabolism , Indoles/metabolism , Piperazines/metabolism , Plant Diseases/microbiology , Raphanus/microbiology , Streptomyces/drug effects , Tryptophan/pharmacology , Gene Expression , Gene Expression Regulation, Bacterial , Genes, Plant/genetics , Germ-Free Life , Host-Pathogen Interactions , Plant Growth Regulators/metabolism , Raphanus/genetics , Raphanus/physiology , Seedlings/genetics , Seedlings/metabolism , Streptomyces/genetics , Streptomyces/metabolism , Streptomyces/pathogenicity , Time Factors , VirulenceABSTRACT
Primary CNS tumors are the leading cause of cancer-related death in pediatrics. It is essential to understand treatment trends to interpret national survival data. In Canada, children with CNS tumors are treated at one of 16 tertiary care centers. We surveyed pediatric neuro-oncologists to create a national standard of practice to be used in the absence of a clinical trial for seven of the most prevalent brain tumors in children. This allowed description of practice across the country, along with a consensus. This had a multitude of benefits, including understanding practice patterns, allowing for a basis to compare in future research and informing Health Canada of the current management of patients. This also allows all children in Canada to receive equivalent care, regardless of location.
ABSTRACT
Girls with pathogenic variants in FMR1, the gene responsible for Fragile X syndrome, have received relatively little attention in the literature. The reports of girls with trinucleotide expansions or deletions affecting FMR1 describe variable phenotypes; having normal intelligence and no severe neurologic sequelae is not uncommon. We reviewed epilepsy genetics research databases for girls with FMR1 pathogenic variants and seizures to characterize the spectrum of epilepsy phenotypes. We identified 4 patients, 3 of whom had drug-resistant focal epilepsy. Two had severe developmental and epileptic encephalopathy with late-onset epileptic spasms. Our findings demonstrate that FMR1 loss-of-function variants can result in severe neurologic phenotypes in girls. Similar cases may be missed because clinicians may not always perform Fragile X testing in girls, particularly those with severe neurodevelopmental impairment or late-onset spasms.
Subject(s)
Drug Resistant Epilepsy/genetics , Fragile X Mental Retardation Protein/genetics , Fragile X Syndrome/genetics , Intellectual Disability/genetics , Loss of Function Mutation , Adolescent , Adult , Brain Diseases/genetics , Child , Child, Preschool , Female , Humans , Retrospective StudiesABSTRACT
BACKGROUND: Activation of the mammalian target of rapamycin (mTOR) signaling pathway is thought to be a key driver of tumor growth in Merlin (NF2)-deficient tumors. Everolimus is an oral inhibitor of mTOR complex 1 (mTORC1) with antitumor activity in a variety of cancers. METHODS: We conducted a single-institution, prospective, 2-stage, open-label phase II study to estimate the response rate to everolimus in neurofibromatosis type 2 (NF2) patients with progressive vestibular schwannoma (VS). Ten eligible patients were enrolled, including 2 pediatric patients. Everolimus was administered at a daily dose of 10 mg (adults) or 5 mg/m(2)/day (children <18 y) orally in continuous 28-day courses, for up to 12 courses. Response was assessed every 3 months with MRI, using 3-dimensional volumetric tumor analysis, and audiograms. Nine patients were evaluable for the primary response, defined as ≥15% decrease in VS volume. Hearing response was evaluable as a secondary endpoint in 8 patients. RESULTS: None of the 9 patients with evaluable disease experienced a clinical or MRI response. No objective imaging or hearing responses were observed in stage 1 of the trial, and the study was closed according to predefined stopping rules. CONCLUSION: Everolimus is ineffective for the treatment of progressive VS in NF2 patients. We are currently conducting a pharmacokinetic/pharmacodynamic ("phase 0") study of everolimus in presurgical VS patients to elucidate the biological basis for apparent treatment resistance to mTORC1 inhibition in these tumors.
Subject(s)
Antineoplastic Agents/therapeutic use , Neurofibromatosis 2/drug therapy , Neuroma, Acoustic/drug therapy , Sirolimus/analogs & derivatives , Adolescent , Adult , Antineoplastic Agents/pharmacokinetics , Child , Disease Progression , Everolimus , Female , Follow-Up Studies , Humans , Magnetic Resonance Imaging , Male , Neoplasm Staging , Neurofibromatosis 2/complications , Neurofibromatosis 2/mortality , Neuroma, Acoustic/complications , Neuroma, Acoustic/mortality , Prognosis , Prospective Studies , Sirolimus/pharmacokinetics , Sirolimus/therapeutic use , Survival Rate , Young AdultABSTRACT
BACKGROUND: Activation of the RAS-RAF-MEK-ERK signaling pathway is thought to be the key driver of pediatric low-grade astrocytoma (PLGA) growth. Sorafenib is a multikinase inhibitor targeting BRAF, VEGFR, PDGFR, and c-kit. This multicenter phase II study was conducted to determine the response rate to sorafenib in patients with recurrent or progressive PLGA. METHODS: Key eligibility criteria included age ≥ 2 years, progressive PLGA evaluable on MRI, and at least one prior chemotherapy treatment. Sorafenib was administered twice daily at 200 mg/m(2)/dose (maximum of 400 mg/dose) in continuous 28-day cycles. MRI, including 3-dimensional volumetric tumor analysis, was performed every 12 weeks. BRAF molecular testing was performed on tumor tissue when available. RESULTS: Eleven patients, including 3 with neurofibromatosis type 1 (NF1), were evaluable for response; 5 tested positive for BRAF duplication. Nine patients (82%) came off trial due to radiological tumor progression after 2 or 3 cycles, including 3 patients with confirmed BRAF duplication. Median time to progression was 2.8 months (95% CI, 2.1-31.0 months). Enrollment was terminated early due to this rapid and unexpectedly high progression rate. Tumor tissue obtained from 4 patients after termination of the study showed viable pilocytic or pilomyxoid astrocytoma. CONCLUSIONS: Sorafenib produced unexpected and unprecedented acceleration of tumor growth in children with PLGA, irrespective of NF1 or tumor BRAF status. In vitro studies with sorafenib indicate that this effect is likely related to paradoxical ERK activation. Close monitoring for early tumor progression should be included in trials of novel agents that modulate signal transduction.
Subject(s)
Antineoplastic Agents/therapeutic use , Astrocytoma/drug therapy , Brain Neoplasms/drug therapy , Niacinamide/analogs & derivatives , Phenylurea Compounds/therapeutic use , Adolescent , Animals , Astrocytoma/mortality , Astrocytoma/pathology , Brain Neoplasms/mortality , Brain Neoplasms/pathology , Child, Preschool , Female , Humans , Kaplan-Meier Estimate , MAP Kinase Signaling System/drug effects , Magnetic Resonance Imaging , Male , Mice , NIH 3T3 Cells , Niacinamide/administration & dosage , Niacinamide/therapeutic use , Phenylurea Compounds/administration & dosage , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/therapeutic use , Sorafenib , Treatment OutcomeABSTRACT
Recent studies highlight the importance of BRAF alterations resulting in mitogen activated protein kinase (MAK/ERK) pathway activation in low-grade CNS tumors. We studied 106 low-grade CNS neoplasms in a cohort of primarily pediatric patients to identify the prevalence and clinicopathologic significance of these alterations. Polymerase chain reaction testing identified KIAA1549:BRAF fusions in 51 (48%) tumors overall, including 42 (60%) pilocytic astrocytomas, 4 (17%) unclassifiable low-grade gliomas, 4 (36%) low-grade glioneuronal/neuroepithelial tumors, 0 (of 5) pleomorphic xanthoastrocytomas, 0 (of 4) diffuse astrocytomas (World Health Organization grade II), and 1 (of 3, 33%) pilomyxoid astrocytoma. KIAA1549:BRAF gene fusions confirmed by sequencing included the previously reported ones involving exons 1-16/9-18 (49%), 1-15/9-18 (35%), and 1-16/11-18 (8%) and 2 fusions with novel breakpoints: 1-15/11-18 (6%) and 1-17/10-18 (1%). DNA sequencing identified BRAF mutations in 8% of tumors. BRAF mutations were absent. KIAA1549:BRAF fusions were significantly more frequent in infratentorial (57%) and optic pathway (59%) tumors versus supratentorial (19%) tumors (p = 0.001). We did not identify significantly improved progression-free survival in tumors with fusions. In summary, KIAA1549:BRAF fusions predominate in pilocytic astrocytomas but are also present in some low-grade unclassifiable gliomas and glioneuronal tumors. The prognostic and therapeutic significance of this alteration is unclear and merits further study.
Subject(s)
Biomarkers, Tumor/genetics , Brain Neoplasms/genetics , Genetic Variation/genetics , Point Mutation/genetics , Proto-Oncogene Proteins B-raf/genetics , Recombinant Fusion Proteins/genetics , Adolescent , Adult , Brain Neoplasms/pathology , Child , Child, Preschool , Cohort Studies , Female , Follow-Up Studies , Glioma/genetics , Glioma/pathology , Humans , Infant , Male , Neuroglia/pathology , Neurons/pathology , Retrospective Studies , Young AdultABSTRACT
This single-institution phase II study was performed to estimate the response rate to lapatinib in neurofibromatosis type 2 (NF2) patients with progressive vestibular schwannoma (VS). Twenty-one eligible patients were enrolled. Brain and spine MRIs, including 3-dimensional volumetric tumor analysis, and audiograms were performed once at baseline and again every 12 weeks. The primary response end point was evaluable in 17 patients and defined as ≥15% decrease in VS volume. Hearing was evaluable as a secondary end point in 13 patients, with responses defined as an improvement in the pure tone average of at least 10 dB or a statistically significant increase in word recognition scores. Four of 17 evaluable patients experienced an objective volumetric response (23.5%; 95% confidence interval [CI], 10%-47%), with median time to response of 4.5 months (range, 3-12). In responders, reduction in VS volumes ranged from -15.7% to -23.9%. Four of 13 patients evaluable for hearing met hearing criteria for response (30.8%; 95% CI, 13%-58%). One sustained response exceeded 9 months in duration. Median time to overall progression (ie, volumetric progression or hearing loss) was 14 months. The estimated overall progression-free survival and volumetric progression-free survival at 12 months were 64.2% (95% CI, 36.9%-82.1%) and 70.6% (95% CI, 43.1%-86.6%), respectively. Toxicity was generally minor, and no permanent dose modifications were required. Lapatinib carries minor toxicity and has objective activity in NF2 patients with progressive VS, including volumetric and hearing responses. Future studies could explore combination therapy with other molecular targeted agents such as bevacizumab.
Subject(s)
Antineoplastic Agents/therapeutic use , Neurofibromatosis 2/drug therapy , Neuroma, Acoustic/drug therapy , Quinazolines/therapeutic use , Adolescent , Adult , Antineoplastic Agents/pharmacokinetics , Child , Child, Preschool , Female , Follow-Up Studies , Humans , Lapatinib , Magnetic Resonance Imaging , Male , Middle Aged , Neurofibromatosis 2/complications , Neurofibromatosis 2/mortality , Neuroma, Acoustic/complications , Neuroma, Acoustic/mortality , Prognosis , Prospective Studies , Quinazolines/pharmacokinetics , Survival Rate , Tissue Distribution , Young AdultABSTRACT
The impact of treatment given upon discharge on the "bounce back" rate was ascertained in children presenting at the emergency department for treatment of status migrainosus. All children ages 8 to 17 years old presenting to an emergency department in 2008 who were treated for status migrainosus and discharged home were included. Of the total of 187 patients, 21 patients (11.2%) bounced back. Treatment given was not associated with the bounce back rate. The only factors reaching significance were the presence of a migraine equivalent in 28.6% of patients who bounced back as compared with only 6.7% in patients without recurrence (P = .006); brain imaging study in the emergency department (52.4% vs. 16.9%, P = .001); and an arranged physician follow-up (66.6% vs. 36.3%, P = .01). The results appear to suggest that no current treatment given to children presenting to the emergency department with status migrainosus seems to alter the immediate recurrence rate.
Subject(s)
Migraine Disorders/therapy , Secondary Prevention , Adolescent , Child , Emergency Service, Hospital , Female , Follow-Up Studies , Humans , Male , Patient Discharge , Risk Factors , Treatment OutcomeABSTRACT
A population-based registry was used to ascertain whether neuroimaging findings of children with cerebral palsy could predict the occurrence of certain comorbidities. Neuroimaging findings and comorbidities data were extracted from the Quebec Cerebral Palsy Registry for children born in a 4-year birth interval (1999-2002) covering half of the province's population. Neuroimaging studies were classified into 10 mutually exclusive categories (periventricular white matter injury/leukomalacia, cerebral malformation, cerebral vascular accident, deep gray matter injury, superficial gray matter injury, diffuse gray matter injury, intracranial hemorrhage, infection, nonspecific findings, and normal). Comorbidities studied included cortical blindness, severe auditory impairment, inability to communicate verbally, assisted feeding, and the presence of afebrile seizures in the prior 12 months. Neuroimaging results were available for a total of 213 children. Only deep gray matter injury (defined as signal abnormality or volume loss in subcortical gray matter, n = 9) was significantly (P < 0.05) linked with the occurrence of both the inability to communicate verbally (n = 5, 55.6% vs n = 46, 22.5%, P = 0.04) and with a higher mean number of comorbidities (1.67 vs 0.70, P < 0.01), and therefore with increased burden of comorbidities. These findings may improve our ability to prognosticate the outcome of children with cerebral palsy, enabling targeted early direct interventions.