Chemotherapy For Brain Tumors Research Articles

CNSC-04. UNDERSTANDING PEDIATRIC BRAIN TUMOR CHEMOTHERAPY INDUCED LONG-TERM DEFICITS IN HIGH-ORDER NEUROCOGNITIVE AND SENSORIMOTOR FUNCTION

Abstract Because of major advancements in cancer treatment especially chemotherapy, 85% of children with cancer are predicted to survive for 5 years or more. However, chemotherapy can cause long-term health problems when childhood cancer survivors enter adulthood (known as late effects). The neurocognitive features of these late effects (chemobrain) include trouble in concentrating, memorizing, and decreased processing speed, and results in lower IQ and academic achievement, poor hand-eye coordination, and slower development over time. Despite such a negative impact on the quality of life of cancer-surviving children, the mechanism is poorly understood and there is no FDA-approved drug to prevent or cure these side effects. To gain a better understanding of the mechanism underlying chemotherapy-induced cognitive impairments, we developed a pre-clinical model using carboplatin in juvenile mice to study long-term neurological defects. Carboplatin is commonly used chemotherapy drug in pediatric brain tumor patients. We have tested the capacity of different doses of carboplatin and its long-term effect on cognitive and sensorimotor function and performed single nuclear RNA sequencing (snRNAseq) of the hippocampus. Our preliminary data demonstrated dose-dependent deficits in executive and sensorimotor function 7-9 weeks after carboplatin administration in the mice of both sexes. snRNAseq of the hippocampus showed changes in the glial cell number as well as genes associated with oxidative phosphorylation and neurodegeneration at early and late time points. Bioenergetics using Seahorse in the brain synaptosomes revealed mitochondrial dysfunction in the form of decreased maximum respiratory capacity long after carboplatin treatment. This study established a preclinical model that can be leveraged to mechanistically understand the long-term neurocognitive side effects of brain tumor chemotherapy during childhood. Future studies will aim to identify potential targets to prevent and/or treat the neurotoxic effects of cancer treatment in pediatric patients.

ETMR-08. DECODING TUMOR-NEURONAL COMMUNICATION IN PEDIATRIC BRAIN TUMORS: INSIGHTS FROM ETMR 3D MODEL REVEALING MECHANO-SIGNALING DYNAMICS AND THERAPEUTIC OPPORTUNITIES

Abstract INTRODUCTION Exploring tumor-neuronal interactions is essential for comprehending brain tumor proliferation, chemotherapy resistance, and patient survival. While glioma research has made significant strides, our understanding of tumor-neuronal interactions in pediatric brain tumors, notably Embryonal Tumors with Multilayered Rosettes (ETMRs), remains limited. METHODS To elucidate tumor-neuronal interactions in ETMRs, we developed a 3D model by co-aggregating the human ETMR cell line BT-183 with human induced pluripotent stem cells (iPSCs) and allowing them to mature into forebrain organoids for 30 days, forming ETMR-forebrain organoids (ETMR-FBO). We further employed single-cell RNA sequencing to compare the gene expression profile of healthy forebrain organoids (FBO) with the ETMR-FBOs. Additionally, we conducted immunohistochemistry of 3D model sections for comparative evaluation and spatial transcriptomics of murine and human primary ETMR samples. RESULTS Our integrated dataset of 48,764 cells of healthy FBOs (n = 4) and ETMR-FBOs (n = 6) revealed that ETMR tumor cells impeded the neuronal differentiation of the FBO cells. The ETMR-FBOs exhibited a significant enrichment of neuro-stem cells (67% vs 49%), accompanied by a reduction of more differentiated neuronal cells. Comparative trajectory analysis confirmed a blockage of neuronal maturation/differentiation in ETMR-FBOs compared to controls without ETMR cells. Immunohistochemistry further confirmed an enrichment of SOX2-positive/synaptophysin-negative neuronal progenitors in the organoid areas closest to the tumor border. Additionally, we identified upregulated extracellular matrix-related pathways, particularly integrin and YAP/TEAD signaling, in the neuro-stem cell compartment of ETMR-FBOs. This implies a tumor-specific mechano-signaling mechanism influencing the neuronal differentiation state of the tumor microenvironment. CONCLUSION Our findings suggest that mechano-signaling-related tumor-neuronal interactions in ETMR contribute to the formation of an immature neuronal niche. Targeting mechano-signaling may hold promise for innovative therapies by disrupting tumor architecture and enhancing susceptibility to chemotherapy.

CNSC-01. UNDERSTANDING PEDIATRIC BRAIN TUMOR CHEMOTHERAPY INDUCED LONG-TERM DEFICITS IN HIGH-ORDER NEUROCOGNITIVE AND SENSORIMOTOR FUNCTION

Abstract BACKGROUND Because of major advancements in cancer treatment especially chemotherapy, 85% of children with cancer are predicted to survive for 5 years or more. However, chemotherapy can cause long-term health problems when childhood cancer survivors enter adulthood (known as late effects). The neurocognitive features of these late effects (chemobrain) include trouble in concentrating, memorizing, and decreased processing speed, and results in lower IQ and academic achievement, poor hand-eye coordination, and slower development over time. Despite such a negative impact on the quality of life of cancer-surviving children, the mechanism is poorly understood and there is no FDA-approved drug to prevent or cure these side effects. METHODS To gain a better understanding of the mechanism underlying chemotherapy-induced cognitive impairments, we developed a pre-clinical model using carboplatin in juvenile mice to study long-term neurological defects. We have tested the capacity of different doses of carboplatin and its long-term effect on cognitive and sensorimotor function and performed single nuclear RNA sequencing (snRNAseq) of the hippocampus. RESULTS Our preliminary data demonstrated dose-dependent deficits in executive and sensorimotor function 7-9 weeks after carboplatin administration in the mice of both sexes. snRNAseq of the hippocampus showed changes in the glial cell number as well as genes associated with oxidative phosphorylation and neurodegeneration at early and late time points. CONCLUSIONS This study established a preclinical model that can be leveraged to mechanistically understand the long-term neurocognitive side effects of brain tumor chemotherapy during childhood. Future studies will aim to identify potential targets to prevent and/or treat the neurotoxic effects of cancer treatment in pediatric patients.

Prognostic Factors and Impact of Therapeutic Intervention in Patients With Brain Metastases at the Initial Presentation.

Background Studies investigating the normative characteristics and prognosis of patients diagnosed with brain metastases (BMs) at the onset of cancer are scarce. Therefore, we analyzed real-world treatment options. Methodology This retrospective study enrolled 112 patients newly diagnosed with BM between May 2006 and October 2021. The variables examined included patients' age, sex, recurrence split analysis, Glasgow prognostic score (GPS), number of lesions, tumor size, peripheral brain tumor edema, targeted therapy, supportive care, chemotherapy, and date of onset. Prognostic factors were assessed using recursive partitioning analysis (RPA), graded prognostic assessment (GPA) scores, and GPS scoring, with magnetic resonance imaging (MRI) andcomputed tomography (CT) studies. Primary treatment comprised whole-brain radiotherapy (WBRT), with regular follow-up. Results Data from 112 survivors were analyzed, revealing a median overall survival time (MST) of 7.7 months, with some patients surviving beyond 24 months post-WBRT. Univariate analysis revealed associations between MST and RPA class, GPS, and treatment modalities (including targeted therapy and chemotherapy). RPA class 2, GPSof 0, and targeted therapy were identified as predictors of better prognosis in the multivariate analysis. In the subgroup not receiving chemotherapy, no significant difference in prognosis was seen between groups with or without WBRT. Conclusions Alongside RPA, scores indicating chronic inflammatory changes, including GPS, were confirmed as crucial prognostic factors. Moreover, treatment with molecularly targeted drugs correlated with favorable prognoses. The treatment-naïve group exhibited poorer prognoses, and WBRT was not deemed a significant prognostic factor in the chemotherapy group.

56 Genetic Models for Long-Term Neurocognitive Outcomes in Pediatric Medulloblastoma and Traumatic Brain Injury

Objective:Children who suffer from brain insults (i.e., traumatic brain injury (TBI), chemotherapy and radiation treatment for brain tumors) are susceptible to late-emerging cognitive sequelae. Even with similar neurological risk variables, variability in long-term cognitive outcomes remains an area of investigation for researchers of acquired brain injury. Given the potential for genetic factors to influence response to chemoradiation, researchers have examined associations between germline, inherited, single nucleotide polymorphisms (SNPs), and neurocognitive outcomes for cancer survivors. Children who sustain an uncomplicated mild TBI generally recover without long-term neuropsychological consequences. However, TBI survivors have overlapping mechanism categories with cancer survivors through secondary injury variables that can be influenced by genomic variation (e.g., oxidative stress and neuroinflammation). Furthermore, the study of genomic vulnerability is limited in heterogenous groups of pediatric TBI survivors. This study aims to identify associations between genotype and long-term neurocognitive outcomes for acquired brain injury survivors by utilizing machine learning to uncover pathophysiological similarities and differences between groups.Participants and Methods:Fourteen brain tumor survivors, 139 traumatic brain injury survivors, and 63 healthy, age-matched controls completed the Letter N-back task to obtain performances on core neurocognitive skills (attention, working memory, and processing speed). Ten targeted genotypes were examined across five pathophysiological pathways (neurotransmission, oxidative stress, neuroinflammation, plasticity, growth and repair, and folate metabolism). Data were trained and tested utilizing three regression machine learning models. Mean estimated error and R2 were generated for each neurocognitive outcome. A feature importance score for models with positive variance was generated to determine how predictive a given SNP is for neurocognitive outcomes.Results:Genotype only accounted for a small amount of variance in cognitive outcomes when all clinical groups were combined. The mean absolute error for the best-fitting models from analyses where all groups were combined decreased when groups were examined separately; however, the differences in model R2 values were not significant. The relationship between brain tumor survivors and processing speed performance depended on genotype. Two SNPs had positive feature importance at the interaction level (rs58225473 and rs1801394). These SNPs are located on the CACNB2 and MTR genes and have functional consequences for neurotransmission and folate metabolism. Models of traumatic brain injury survivors did not explain positive variance and could not be examined for feature importance. Additionally, even when removing the only mechanism of action that should not be relevant for TBI survivors (folate metabolism polymorphisms), the TBI models still did not explain positive variance.Conclusions:Findings of the importance of two key SNPs on MTR and CACNB2 genes align with recent systematic reviews, which found associations between these polymorphisms and neuropsychological outcomes in more than one group or cohort of pediatric cancer survivors. Models for TBI survivors were limited by the heterogeneity of the group and ceiling effects on performance. An understanding of genetic vulnerabilities influenced by treatment and injury-related factors in acquired brain injury will inform our understanding of the developing and recovering childhood brain. The current study is an initial contribution to this goal and highlights the utility of machine learning methodology for future studies that examine the influence of genetic heterogeneity in pediatric acquired brain injury.

Quantitative profiling of genes associated with cancer pathways in brain tumors.

Brain tumors are a heterogeneous group of malignancies characterized by inter- and intratumoral heterogeneity. Among them, the most aggressive and, despite advances in medicine, still incurable remains glioblastoma. One of the reasons is the high recurrence rate of the disease and resistance to temozolomide, a golden standard in chemotherapy of brain tumors. Therefore, mapping the pathways responsible for tumorigenesis at the transcriptional level may help to determine the causes and aggressive behavior among different glial tumors. Biopsies from patients with astrocytoma (N = 6), glioblastoma (N = 22), and meningioma (N = 14) were included in the sample set. A control group consisted of RNA isolated from healthy human brain (N = 3). The reverse-transcribed cDNAs were analyzed using the Human Cancer PathwayFinder™ real-time PCR Array in a 96-well format. The expression of 84 genes belonging to 9 signaling pathways (angiogenesis, apoptosis, cell cycle and senescence, DNA damage and repair, epithelial-to-mesenchymal transition, hypoxia, overall metabolism, and telomere dynamics) was determined for each sample. By determining the relative expression of selected genes, we characterized the transcriptomic profile of individual brain malignancies in the context of signaling pathways involved in tumorigenesis. We observed deregulation in 50, 52.4 and 53.6% % of the genes in glioblastomas, meningiomas and astrocytomas, respectively. The most pronounced changes with statistical significance compared to control were observed in the genes associated with epithelial-to-mesenchymal transition (CDH2, FOXC2, GSC, SNAI2, and SOX10), cellular senescence (BMI1, ETS2, MAP2K1, and SOD1), DNA repair (DDB2, ERCC3, GADD45G, and LIG4), and dynamic of telomeres (TEP1, TERF2IP, TNKS, and TNKS2). Based on the obtained data, we can conclude that individual diagnoses differ in transcriptomic profile. An individual molecular approach is therefore necessary in order to provide comprehensive and targeted therapy on multiple metabolic pathways in the diagnosis of brain tumors.

Survival and functional recovery of primary cortical neurons exposed to actinomycin D

Actinomycin D (ActD) is an antineoplastic antibiotic that has been commonly used for the treatment of various tumors, including Wilms’ tumor, rhabdomyosarcoma, and gestational trophoblastic neoplasia. Recent studies have proposed actinomycin D (ActD) as a novel therapeutic candidate for glioblastoma. ActD significantly reduces tumor growth in recurrent glioblastoma patient-derived mouse models and increases survival by downregulating SOX2 expression. However, ActD treatment of brain tumors can lead to unnecessary exposure of surrounding neurons and normal glial cells to ActD. Cellular and molecular studies are required to estimate and minimize the neurological side effects of ActD. This study investigated the short- and long-term toxicological responses of the primary cortical neurons to ActD. We examined concentration-dependent survival of primary cortical neurons and differential susceptibilities of excitatory, inhibitory neurons, and glial cells to ActD. Distinct alterations in intracellular signaling pathways in cortical neurons were also studied when exposed to ActD. Importantly, we found that primary cortical neurons after ActD discontinuation showed active intracellular signaling pathways responding to extracellular neurotropic factors, but they had extremely poor transcription activity reversibility that was inhibited even by 30-min low-dose ActD exposure. These findings indicate the direct toxicity and extremely poor reversibility of ActD in neurons during chemotherapy for brain tumors.

Neurosurgically-Applied Chemotherapy for Childhood Brain Tumours Arising in the Posterior Fossa Using a Biodegradable Paste

Abstract AIMS This project aims to develop a local drug delivery system for treatment of childhood medulloblastoma (MB) and atypical teratoid/rhabdoid tumours (AT/RT), malignant brain neoplasms occurring in the posterior fossa for which prognoses remains poor. Our goal is to repurpose drug compounds reported as effective against MB and AT/RT, but which either cannot cross the blood-brain-barrier (BBB) or have not been assessed for localised delivery. We have developed a novel intra-cavity drug delivery system, consisting of polymer microparticles made from poly(DL-lactic-co-glycolic acid) and poly(ethylene glycol) (PLGA/PEG) which will be employed to release drugs over several weeks. METHOD Cell toxicity assays were undertaken using drugs of interest against an in vitro panel of relevant MB and AT/RT cell lines. PLGA/PEG paste incorporating the drugs were prepared and release kinetics assessed. RESULTS IC50 values of the drugs were assessed across all cell lines and a range of potencies were observed, with optimum conditions identified as dual treatments of PG545 (heparanse inhibitor) with CHIR99021 (glycogen synthase kinase-3 inhibitor) for MB and ribavirin (anti-viral) with CHIR99021 for AT/RT. Importantly, it was noted that the drugs retained their cytotoxicity following release from PLGA/PEG. Furthermore, release kinetics were finely tuned through careful control of the composition through addition of excipients and encapsulation of drugs in nanoparticles, and a library of formulations were prepared. CONCLUSION A local drug delivery system for MB and AT/RT has been developed and an optimum formulation, based upon in vitro cell assays and release kinetics, has been identified for in vivo efficacy studies in orthotopic models.

RONC-05. Peri-transplant Radiation Therapy for Young Children Treated with High-Dose Chemotherapy for Primary Brain Tumors

PURPOSE: The role of peri-transplant radiation therapy (RT) in young children with primary brain tumors is unclear. We characterized our institutional practice patterns and patient outcomes. MATERIALS AND METHODS: The cohort included all patients treated with high-dose chemotherapy for primary brain tumors at our institution from 2011-2017. Rates of local control (LC), progression-free survival (PFS), overall survival (OS), and radiation-associated injury were assessed. RESULTS: Of 37 eligible patients, 29 (78%) received peri-transplant RT at a median age of 4 years. Patients treated with RT were more likely to have metastatic (p=0.0121) and incompletely resected (p=0.056) disease, and to have high-risk histologies including atypical teratoid rhabdoid tumor, nongerminomatous germ cell tumor, pineoblastoma, primitive neuro-ectodermal tumor, glioneuronal tumor and group 3 medulloblastoma. Of those treated with RT, 13 (45%) received craniospinal irradiation (CSI) and 16 (55%) received focal RT. The median CSI dose was 23.4 Gy (IQR: 18-36; boost median 54 Gy [IQR: 53.7-55.8]) and focal RT dose was 50.4 Gy (IQR: 50.4-54.5). Compared to the focal RT group, patients treated with CSI were older (p=0.0499) and more likely to have metastatic disease (p=0.0004). For the complete cohort, at a median follow-up of 3.8 years, the 2-year rate of LC was 82% (95% CI: 70-96%), PFS was 63% (95% CI: 49-81%), and OS was 65% (95% CI: 51-82%). These rates did not differ significantly between patients treated with and without peri-transplant RT. Two cases of fatal myelopathy were observed after spinal cord doses within the highest tertile (41.4 CGE and 36 Gy); both cases occurred in patients who received RT before high-dose chemotherapy. CONCLUSION: Peri-transplant RT was used for high-risk disease. Oncologic outcomes after RT were encouraging. However, 2 cases of grade 5 myelopathy were observed. If used cautiously, RT may contribute to durable remission in patients at high risk of relapse.

Supramolecular Hydrogel Based Post-Surgical Implant System for Hydrophobic Drug Delivery Against Glioma Recurrence.

PurposeThe brain, protected by the cranium externally and the blood–brain barrier (BBB) internally, poses challenges in chemotherapy of aggressive brain tumors. Maximal tumor resection followed by radiation and chemotherapy is the standard treatment protocol; however, a substantial number of patients suffer from recurrence. Systemic circulation of drugs causes myelodysplasia and other side effects. To address these caveats, we report facile synthesis of a polyester-based supramolecular hydrogel as a brain biocompatible implant for in situ delivery of hydrophobic drugs.MethodsPolycaprolactone-diol (PCL) was linked to polyethyleneglycol-diacid (PEG) via an ester bond. In silico modeling indicated micelle-based aggregation of PCL-PEG co-polymer to form a supramolecular hydrogel. Brain biocompatibility was checked in Sprague Dawley rat brain cortex with MRI, motor function test, and histology. Model hydrophobic drugs carmustine and curcumin entrapment propelled glioma cells into apoptosis-based death evaluated by in vitro cytotoxicity assays and Western blot. In vivo post-surgical xenograft glioma model was developed in NOD-SCID mice and evaluated for efficacy to restrict aggressive regrowth of tumors.Results20% (w/v) PCL-PEG forms a soft hydrogel that can cover the uneven and large surface area of a tumor resection cavity and maintain brain density. The PCL-PEG hydrogel was biocompatible, and well-tolerated upon implantation in rat brain cortex, for a study period of 12 weeks. We report for the first time the combination of carmustine and curcumin entrapped as model hydrophobic drugs, increasing their bioavailability and yielding synergistic apoptotic effect on glioma cells. Further in vivo study indicated PCL-PEG hydrogel with a dual cargo of carmustine and curcumin restricted aggressive regrowth post-resection significantly compared with control and animals with intravenous drug treatment.ConclusionPCL-PEG soft gel-based implant is malleable compared with rigid wafers used as implants, thus providing larger surface area contact. This stable, biocompatible, supramolecular gel without external crosslinking can find wide applications by interchanging formulation of various hydrophobic drugs to ensure and increase site-specific delivery, avoiding systemic circulation.

Promising Chemotherapy for Malignant Pediatric Brain Tumor in Recent Biological Insights.

Brain tumors are the most widespread malignancies in children around the world. Chemotherapy plays a critical role in the treatment of these tumors. Although the current chemotherapy process has a remarkable outcome for a certain subtype of brain tumor, improving patient survival is still a major challenge. Further intensive treatment with conventional non-specific chemotherapy could cause additional adverse reactions without significant advancement in survival. Recently, patient derived brain tumor, xenograft, and whole genome analysis using deep sequencing technology has made a significant contribution to our understanding of cancer treatment. This realization has changed the focus to new agents, targeting the molecular pathways that are critical to tumor survival or proliferation. Thus, many novel drugs targeting epigenetic regulators or tyrosine kinase have been developed. These selective drugs may have less toxicity in normal cells and are expected to be more effective than non-specific chemotherapeutics. This review will summarize the latest novel targets and corresponding candidate drugs, which are promising chemotherapy for brain tumors according to the biological insights.

Searching for a cure on Facebook: Patterns of social media use amongst caregivers of children with brain tumors.

ObjectiveSocial media (SM) is ubiquitous in modern society. How SM provides information, advice, and community to families coping with childhood brain tumors is poorly understood. We sought to understand how caregivers of children with brain tumors use and are affected by SM.MethodsA survey was administered to caregivers of children who were receiving or within the last 5 years received chemotherapy for pediatric brain tumors. Differences in variables across groups were evaluated using nonparametric tests and chi‐square tests.ResultsThirty‐five of 36 caregivers acknowledged use of SM. Facebook was the most used platform (86%). Fifty‐eight percent and 47% used SM to read and share information about their child's cancer, respectively. Thirty‐four percent were comforted while 40% were bothered by cancer‐related information on SM. Eleven participants (31%) sought a second opinion based on information from SM. Caregivers of children with a poor prognosis were more likely to use a treatment from SM that was not initially recommended by their oncologist (p = 0.043).ConclusionSM is commonly used by caregivers to obtain and share care‐related information. Many noted positive and negative effects of SM on emotional wellness. SM influenced treatment decisions, and this effect was stronger with poorer prognosis. Our results demonstrate the dichotomous impact of SM in medicine—it is a source of both solace and anxiety, a place to confirm treatment decisions and to create doubt in the treatment decisions of the oncologist. This illustrates the importance of discussing SM with caregivers of children with brain tumors.

Radiation Therapy for Young Children Treated With High-Dose Chemotherapy and Autologous Stem Cell Transplant for Primary Brain Tumors

Purpose: The role of peri-transplant radiation therapy (RT) in children with primary brain tumors is unclear. We characterized our institutional practice patterns and patient outcomes. Methods and MaterialsThe cohort included all patients treated with high-dose chemotherapy and autologous stem cell transplant for primary brain tumors at our institution from 2011 to 2017. Rates of local control, progression-free survival, overall survival, and radiation-associated injury were assessed. ResultsOf the 37 eligible patients, 29 (78%) received peri-transplant RT. Patients treated with RT were more likely to have metastatic (P = .0121) and incompletely resected (P = .056) disease. Of those treated with RT, 13 (45%) received craniospinal irradiation (CSI) and 16 (55%) received focal RT. The median CSI dose was 23.4 Gy (interquartile range [IQR], 18-36 Gy; boost: median, 54 Gy [IQR, 53.7-55.8 Gy]) and focal RT dose was 50.4 Gy [IQR, 50.4-54.5 Gy]). Compared with the focal RT group, patients treated with CSI were older (P = .0499) and more likely to have metastatic disease (P = .0004). For the complete cohort, 2-year local control was 82% (95% confidence interval [CI], 70%-96%), progression-free survival 63% (95% CI, 49%-81%), and overall survival 65% (95% CI, 51%-82%). These rates did not differ significantly between patients treated with and without peri-transplant RT. Two cases of fatal myelopathy were observed after spinal cord doses within the highest tertile (41.4 cobalt Gy equivalent and 36 Gy). ConclusionsPeri-transplant RT was used for high-risk disease. Oncologic outcomes after RT were encouraging. However, 2 cases of grade 5 myelopathy were observed. If used cautiously, RT may contribute to durable remission in patients at high risk of relapse.

Nitric oxide donor nitrosorbide potentiates the antitumor effect of doxorubicin against experimental glioblastoma

Doxorubicin is a well-known antitumor drug that is not employed for chemotherapy of brain tumors. Indeed, doxorubicin does not penetrate across the blood-brain barrier in therapeutic concentrations. To study the antitumor effect of doxorubicin combined with nitrosorbide on intracranial experimental glioblastoma 101/8 in rats. Male Wistar rats (n=86) with intracranial implanted glioblastoma 101/8 received doxorubicin (i.v. 1.5 mg/kg thrice) alone or in combination with nitrosorbide (i.v or orally, 0.5 mg/kg thrice) in 2, 5 and 8 days after implantation. Efficacy was assessed considering survival and brain tumor volume in 14 days after tumor implantation. Combination of doxorubicin and nitrosorbide significantly increased survival (57% and 155%, respectively) and slowed down tumor growth (16±12 and 8±6 mm3, respectively) compared to doxorubicin alone. Effectiveness of nitrosorbide alone was trivial. Nitric oxide donor nitrosorbide considerably potentiated the antitumor effect of doxorubicin against intracranial 101/8 glioblastoma in rats.

MET-11 Recent advances in targeted therapies and immunotherapy for metastatic brain tumors

This presentation outlines CQ2 of Chapter 2 from the forthcoming updated version of the Clinical Practice Guidelines for Brain Tumors, edited by the Society. These guidelines discuss chemotherapy and other drug therapies for metastatic brain tumors in adult patients. First, there is no noteworthy change in the principle of prioritizing local treatment of symptomatic metastatic brain tumors or those that require local treatment in the near future. However, with recent advances in molecular-targeted drugs and/or immune checkpoint inhibitors, many physicians now consider starting systemic treatment prior to local treatment of brain metastases, even in patients with solid tumors that were once considered insensitive to chemotherapy, given that their symptoms are well-controlled and do not require urgent treatment. In the treatment of non-small cell lung cancer (NSCLC), the molecular subtypes of metastatic brain tumors with EGFR mutations and ALK fusion genes have yielded favorable responses to molecular-targeted drugs. Because small molecule drugs are well delivered to the central nervous system, systemic drug therapy with such targeted drugs is commonly selected for patients with untreated metastatic brain tumors. A recent phase II trial has shown the effectiveness of anti-PD-1 antibody pembrolizumab monotherapy for metastatic brain tumors from NSCLC. Because untreated metastatic brain tumors from renal cell carcinoma are prone to bleeding, local treatment of brain metastases should be prioritized before systemic treatment, even if the patient is asymptomatic. Regardless of BRAF mutation status, immune checkpoint inhibitors alone or in combination (nivolumab and ipilimumab) are effective against malignant melanoma with brain metastases; moreover, a combined treatment with BRAF and MEK inhibitors is effective against BRAF mutation-positive malignant melanoma with brain metastases. A novel HER2 inhibitor, tucatinib (unapproved), is expected to be effective against metastatic brain tumors from HER2-positive breast cancer.

Lyapunov based nonlinear controllers for the chemotherapy of brain tumor

Among various methods for the treatment of brain tumor include surgery, chemotherapy, radiation therapy etc. For less severe tumors, i.e. benign, applying surgery is suitable because they are small in size and have definite edges. While in case of severe tumors, i.e. malignant chemotherapy is preferable: suggesting surgery is not always a good option as these tumors do not have definite boundaries and are attached very closely with sensitive tissues of brain. In this research work three nonlinear controllers: (1) Lyapunov redesign, (2) sliding mode, (3) terminal sliding mode based controllers have been designed for the therapeutic agent in an updated model of brain tumor in order to minimize the number of brain tumor cells, to maintain a safe amount of healthy cells, to keep immune cells above a certain value and ensure the use of suitable amount of drug for the therapy. Lyapunov stability theory has been used to analyze the system's asymptotic stability and convergence of the tumor cells to their desired reference. Simulations have been performed in ODE45-Solver using Matlab/Simulink and the results show that chemotherapy is effective enough to get the desired objectives.

Backstepping and Synergetic Controllers for the Chemotherapy of Brain Tumor

The treatment of brain tumors by chemotherapy through the controlled rate of drug has been a challenging task since long. Two nonlinear control algorithms: 1) synergetic 2) backstepping based controllers have been designed for the therapeutic agent in an updated mathematical model of brain tumor to reduce the tumor cells, to maintain a safe amount of healthy cells, to keep the immune cells above a certain value and ensure suitable amount of drug during the therapy. Lyapunov stability theory has been used to analyze the system’s asymptotic stability and convergence of the tumor cells to their desired reference. Simulations have been performed in ODE45-Solver of Matlab/Simulink which show that chemotherapy using proposed controllers is effective enough to get the desired objectives.

Variable Structure Based Control for the Chemotherapy of Brain Tumor

Brain Tumor is an unwanted mass when cells grow abnormally. It puts pressure on certain areas of the brain which dangerously affects its functioning. For severe tumors like malignant, surgery is not a good option because they do not have definite boundaries and are closely attached with the other healthy tissues of the brain. So chemotherapy is preferable in this case to avoid damaging the healthy cells. The primary intention of this research is to suggest a controller for drug injection so that the tumor cells may reach the desired reference value of zero. In this paper, variable structure based nonlinear control algorithms: sliding mode control, integral sliding mode control, double integral sliding mode control and super-twisting sliding mode controllers have been proposed to reduce the tumor cells, maintain a safe number of healthy cells, keep the immune cells above a certain value and ensure suitable amount of chemotherapy drug. Lyapunov based stability theory has been used to prove stability of SMC, ISMC, DISMC and ST-SMC. MATLAB/Simulink environment has been used to analyze the performance of the proposed controllers on the basis of chattering, rate of convergence, undershoot/overshoot etc. and on the basis of these results drug through most suitable controller is advised. Among the proposed controllers, due to its better convergence, reduced chattering and less amount of drug used, ST-SMC is suggested for the chemotherapy of brain tumor.

An eradication agent acting on a binary cell population model: mathematical analysis

In this paper we study a system of partial differential equations that couple nonfickian diffusion of one of two species with the fickian diffusion of a chemical or biological agent. This system can be used to describe the evolution a population (biological species, cells) that switch between two phenotypes: migratory and proliferative. This switching process is very common in certain types of cancer or even viral diseases. It is assumed that the population/cell migration occurs in a viscoelastic extracellular matrix (ECM). This has an important role in the transport inducing to a nonfickian motion. A chemical agent, which can represent, for instance, a treatment drug in a cancer disease scenario, acts on the population according to Michaelis-Menten or linear reactions, eliminating individuals from the population. Under suitable regularity conditions we establish upper bounds for an energy functional, with respect to the L2 norm, leading to the stability of the model. Agent administration protocols based on stronger assumptions on the agent/population kinetics are also proposed with the purpose of controlling the total amount of individuals of the population. These protocols are based on suitable estimates for the total mass of individuals in the system after a certain number of agent administration sessions. A numerical method based on finite differences and finite elements is introduced and its stability properties are analysed. The qualitative behaviour of the solutions of the system is explored and discussed. Several protocols are defined within the context of chemotherapy in brain tumours and their effectiveness is numerically studied considering Michaelis-Menten or linear chemical effects.

Abnormal weight gain with fatigue and stress in early survivorship after childhood brain tumor diagnosis.

Diagnosis and treatment for individuals with brain tumors during childhood involves sequelae, including abnormal weight gain. This symptom is commonly clustered with fatigue and increased risk for cardiovascular disease. Children's Oncology Group recommendations include annual surveillance of body mass index (BMI) and cardiometabolic comorbidities; however, there has been little emphasis on individualized screening early in survivorship. The primary purpose of this paper is to describe the findings of abnormal weight gain and its correlates in a sample of young childhood brain tumor survivors during early survivorship. This cross-sectional multi-site study included brain tumor survivors of ages 8-12 years who were less than 6 years posttreatment. Convenience sampling from two pediatric cancer centers in the southern United States was utilized. Data collected included BMI, parent report of sleep, and child report of fatigue and stress. The sample (N = 21) consisted of children who had received chemotherapy, radiation treatment, and surgery for childhood brain tumor. BMI in overweight and obese categories exceeded normative samples with 38% at or above the 85th percentile. There were clinically significant relationships with fatigue, stress about weight, tumor location, cranial radiation, chemotherapy, and recurrence PRACTICE IMPLICATIONS: Screening for abnormal weight gain and related factors, such as fatigue should begin early in survivorship after childhood brain tumor treatment completion with the aim of health promotion and disease prevention. Adiposity measurement techniques should be utilized in future clinical and research settings to improve assessment of cardiometabolic risk.