Central Nervous System Malignancies Research Articles

Treatment of Central Nervous System Tumors on Combination MR-Linear Accelerators: Review of Current Practice and Future Directions.

Magnetic resonance imaging (MRI) provides excellent visualization of central nervous system (CNS) tumors due to its superior soft tissue contrast. Magnetic resonance-guided radiotherapy (MRgRT) has historically been limited to use in the initial treatment planning stage due to cost and feasibility. MRI-guided linear accelerators (MRLs) allow clinicians to visualize tumors and organs at risk (OARs) directly before and during treatment, a process known as online MRgRT. This novel system permits adaptive treatment planning based on anatomical changes to ensure accurate dose delivery to the tumor while minimizing unnecessary toxicity to healthy tissue. These advancements are critical to treatment adaptation in the brain and spinal cord, where both preliminary MRI and daily CT guidance have typically had limited benefit. In this narrative review, we investigate the application of online MRgRT in the treatment of various CNS malignancies and any relevant ongoing clinical trials. Imaging of glioblastoma patients has shown significant changes in the gross tumor volume over a standard course of chemoradiotherapy. The use of adaptive online MRgRT in these patients demonstrated reduced target volumes with cavity shrinkage and a resulting reduction in radiation dose to uninvolved tissue. Dosimetric feasibility studies have shown MRL-guided stereotactic radiotherapy (SRT) for intracranial and spine tumors to have potential dosimetric advantages and reduced morbidity compared with conventional linear accelerators. Similarly, dosimetric feasibility studies have shown promise in hippocampal avoidance whole brain radiotherapy (HA-WBRT). Next, we explore the potential of MRL-based multiparametric MRI (mpMRI) and genomically informed radiotherapy to treat CNS disease with cutting-edge precision. Lastly, we explore the challenges of treating CNS malignancies and special limitations MRL systems face.

Invasive fungal infections in pediatric patients with central nervous system tumors: novel insights for prophylactic treatments?

Invasive fungal disease (IFD) poses significant morbidity and mortality risks, especially in pediatric patients with neoplastic diseases. However, there is a notable lack of data concerning patients with central nervous system (CNS) tumors. Considering vulnerability factors to infections such as neutropenia, corticosteroids, chemotherapy, surgical interventions, and others, this study aims to evaluate the incidence of IFD in pediatric patients with CNS tumors and determine appropriate indications for prophylactic measures. This is a single-center, retrospective study conducted between 2011 and 2022 at the Pediatric Institute of Oncology (IOP-GRAACC-UNIFESP). A total of 38 cases of IFD were diagnosed in 818 children with CNS malignancies (4,6%). The mean age was 3.5 years (0.4-28y), with 22 (57.9%) male patients. Embryonal tumors (18/38, 47.3%) were the most prevalent CNS tumors, followed by low-grade gliomas (13/38, 34.2%). All episodes met the EORTC IFD criteria, and 36/38 (94.7%) were proven. Invasive yeast infections (33/36, 91.6%), predominantly Candida (30/33, 90.9%), were the most common diagnosis. In total, 25 patients (25/38, 65.8%) were receiving chemotherapy, with 13 of them having embryonal tumors. A total of 11 infants were in the Head Start scheme, resulting in a high prevalence of IFD in these group of patients (11/58, 18.9%). In total, 13 (13/38, 34.2%) patients underwent neurosurgery, mostly ventricular-peritoneal shunts revisions (10/13, 76.9%). Nine (9/38, 23.7%) were with prolonged use of corticosteroids, eight of them associated with neurosurgery. Routine systemic antifungal prophylaxis based solely on diagnosis is not recommended for low-risk cases. Evaluating patient- and treatment-specific risk factors is crucial in infants undergoing high-dose chemotherapy with expected neutropenia and in patients requiring prolonged corticosteroid therapy alongside neurosurgical procedures.

Intraocular Lymphoma and Metastatic Tumors of the Retina

Intraocular lymphomas (IOLs) are a rare, heterogeneous group of malignancies often misdiagnosed and underrecognized. These tumors are often non-Hodgkin's and B-cell type when they occur. Primary IOLs are classified into two groups: primary uveal lymphomas (PULs) and primary vitreoretinal lymphomas (PVRLs). PULs are small cells, low-to-moderately aggressive, relatively benign, and rarely associated with central nervous system (CNS) involvement. PVRLs often diffuse large B-cells, are highly aggressive, and are related to malignant primary CNS lymphoma. Secondary IOLs that metastasize to intraocular structures other than the CNS constitute the last group of IOLs. Secondary IOLs typically metastasize to the choroid and have a poor prognosis due to associated systemic disease. All IOLs are challenging to diagnose, leading to treatment delays. Metastatic tumors are the most common intraocular malignancies. However, metastases mainly occur in the choroid. Retinal metastases are much rarer. Primary tumor sites are the most common skin, gastrointestinal tract, lung, and breast cancers. A biopsy is helpful to confirm the diagnosis and may help locate the primary tumor. Radiotherapy is the most common treatment modality. A multidisciplinary approach is essential in treatment management. Despite successful treatment of retinal metastases, patients have a poor prognosis for survival of primary tumors. This review aims to increase awareness and share diagnostic clues and treatment strategies in these critical and insidious malignancies in light of current literature. IOLs and metastatic tumors of the retina will be evaluated separately under the headings.

Intraoperative Integrated Diagnostic System for Malignant Central Nervous System Tumors.

The 2021 World Health Organization (WHO) classification of central nervous system (CNS) tumors uses an integrated approach involving histopathology and molecular profiling. Because majority of adult malignant brain tumors are gliomas and primary CNS lymphomas (PCNSL), rapid differentiation of these diseases is required for therapeutic decisions. In addition, diffuse gliomas require molecular information on single-nucleotide variants (SNV), such as IDH1/2. Here, we report an intraoperative integrated diagnostic (i-ID) system to classify CNS malignant tumors, which updates legacy frozen-section (FS) diagnosis through incorporation of a qPCR-based genotyping assay. FS evaluation, including GFAP and CD20 rapid IHC, was performed on adult malignant CNS tumors. PCNSL was diagnosed through positive CD20 and negative GFAP immunostaining. For suspected glioma, genotyping for IDH1/2, TERT SNV, and CDKN2A copy-number alteration was routinely performed, whereas H3F3A and BRAF SNV were assessed for selected cases. i-ID was determined on the basis of the 2021 WHO classification and compared with the permanent integrated diagnosis (p-ID) to assess its reliability. After retrospectively analyzing 153 cases, 101 cases were prospectively examined using the i-ID system. Assessment of IDH1/2, TERT, H3F3AK27M, BRAFV600E, and CDKN2A alterations with i-ID and permanent genomic analysis was concordant in 100%, 100%, 100%, 100%, and 96.4%, respectively. Combination with FS and intraoperative genotyping assay improved diagnostic accuracy in gliomas. Overall, i-ID matched with p-ID in 80/82 (97.6%) patients with glioma and 18/19 (94.7%) with PCNSL. The i-ID system provides reliable integrated diagnosis of adult malignant CNS tumors.

Trends in pediatric CNS tumors in Armenia: a multicenter retrospective study.

Central nervous system (CNS) tumors are the most common solid malignancies in children worldwide, including in Armenia. The current study aims to analyze epidemiological data, treatment, and outcomes of children and young adults (≤25 years) with CNS tumors in Armenia during the last 26 years. We collected data from pediatric and young adult patients treated in selected sites in Armenia from 1st January 1995 to 31st December 2020. Incidence by sex, age at diagnosis, time from first complaints to diagnosis, histopathology results, treatment strategies, complications, and overall survival (OS) rates were calculated. The multicenter data analysis revealed 149 patients with diagnosed primary CNS tumors over 26 years. Among them, 84 (56.4%) were male. The median age at diagnosis was 7 years (range, 3 months to 25 years), and the median time from the first complaints to diagnosis was 2 months (range, 1 week to 70 months). Medulloblastomas and other embryonal tumors (47), low-grade gliomas (32), and high-grade gliomas (22) were the most commonly diagnosed malignancies. Ependymomas, craniopharyngiomas, germ cell tumors, and other malignancies were observed in 22 patients. For 26 patients, no histopathological or radiological diagnosis was available. Follow-up information was available for 98 (65.8%) patients. The 5-year OS rate for the whole study group was 67.7%. Consistent with international data, embryonal tumors, and gliomas were the most commonly diagnosed CNS malignancies in Armenia. Multimodal treatment was often not available in Armenia during the study period, especially for early cases.

Spectrum of Diseases Affecting the Nervous System Associated with JC - Virus: A Review

The JC polyomavirus (JCPyV) belongs to the family Polyomaviridae, genus Betapolyomavirus. These are small, non-enveloped, double-stranded DNA viruses. Approximately 60-80% of the population is carriers of JC polyomavirus. Various ways of spread are being studied. These viruses are associated with a large spectrum of neurological diseases, including progressive multifocal leukoencephalopathy, JC-associated meningitis and encephalitis, JCV granule cell neuronopathy and numerous central nervous system malignancies. In the majority of individuals, the virus remains latent in the kidney tissue. However, in certain subgroups, it leads to the development of severe and frequently disabling or fatal diseases. These subgroups are usually immunosuppressed, which causes the virus to undergo lytic rearrangement. Understanding these diseases and the mechanisms by which they occur is paramount for making accurate diagnoses. Studying these diseases is necessary to develop effective treatments and limit their harmful effects.

Positioning SUMO as an immunological facilitator of oncolytic viruses for high-grade glioma.

Oncolytic viral (OV) therapies are promising novel treatment modalities for cancers refractory to conventional treatment, such as glioblastoma, within the central nervous system (CNS). Although OVs have received regulatory approval for use in the CNS, efficacy is hampered by obstacles related to delivery, under-/over-active immune responses, and the "immune-cold" nature of most CNS malignancies. SUMO, the Small Ubiquitin-like Modifier, is a family of proteins that serve as a high-level regulator of a large variety of key physiologic processes including the host immune response. The SUMO pathway has also been implicated in the pathogenesis of both wild-type viruses and CNS malignancies. As such, the intersection of OV biology with the SUMO pathway makes SUMOtherapeutics particularly interesting as adjuvant therapies for the enhancement of OV efficacy alone and in concert with other immunotherapeutic agents. Accordingly, the authors herein provide: 1) an overview of the SUMO pathway and its role in CNS malignancies; 2) describe the current state of CNS-targeted OVs; and 3) describe the interplay between the SUMO pathway and the viral lifecycle and host immune response.

Unraveling the impact of upfront chemotherapy and proton beam therapy on treatment outcome and follow-up in central nervous system germ cell tumors: a single center experience.

Germ cell tumors (GCT) account for a minority of central nervous system (CNS) malignancies, highly prevalent in adolescents and young adults. Despite their aggressive biological behavior, prognosis is excellent in most cases with risk stratified treatment, consisting in a combination of chemotherapy and radiotherapy. Whole ventricular irradiation (WVI) and craniospinal irradiation, the treatment of choice for localized and metastatic disease, pose significant risk of collateral effects, therefore proton beam radiation (PBT) has been recently proposed for its steep dose fallout. We report our experience in a consecutive series of 17 patients treated for CNS GCT at our Institution from 2015 to 2021. Most frequent lesion location were sellar/suprasellar (35%) and bifocal germinoma (35%), followed by pineal (18%) and thalamic (12%). Two patients (12%), had evidence of disseminated disease at the time of diagnosis. At the latest follow-up all but one patient showed complete response to treatment. The only relapse was successfully rescued by additional chemotherapy and PBT. PBT was well tolerated in all cases. No visual, neurological or endocrinological worsening was documented during and after treatment. Neuropsychological evaluation demonstrated preservation of cognitive performance after PBT treatment. Our data, albeit preliminary, strongly support the favourable therapeutic profile of PBT for the treatment of CNS germ cell tumors.

529P Post-marketing surveillance data from patients ≥70 years of age with central nervous system malignancies treated with Tumor Treating Fields (TTFields) therapy between 2011–2022

529P Post-marketing surveillance data from patients ≥70 years of age with central nervous system malignancies treated with Tumor Treating Fields (TTFields) therapy between 2011–2022

Prognostic value of indoleamine 2, 3-dioxygenase-1 expression in glial tumors.

<p>Gliomas are the most common primary malignant central nervous system tumors in adults, exhibiting a poor prognosis. Indoleamine 2, 3-dioxygenase-1 (IDO-1) has important functions in cancer immunotherapy due to its role in escaping cancer cells from the immune system. In this study we purposed to evaluate the correlation between IDO-1 expression and clinicopathological parameters in gliomas, and whether IDO-1 can be a prognostic marker.</p>. <p>n=75 patients in total, n=25 patients with low grade glial tumors (LGG, grade 1-2), n=25 patients with high grade glial tumors (HGG, grade 3-4), and n=25 persons with normal brain tissue as control group were included in this study. IDO-1 expression was categorized by using immunohistochemical staining in biopsy specimens as high (H) and low (L) groups among the patients with gliomas. We used a 95% percent confidence interval and p &lt;0.05 to analyze the association between the degree of IDO-1 expression, clinicopathological characteristics, and survival rates in glioma patients.&nbsp;</p>. <p>In HGG, IDO-1 levels were higher than in control brain tissue and LGG (p&lt; 0.001). The mean overall survival (OS) was longer in the L-IDO-1 group (64.53 &plusmn; 3.34) in months (95% CI: 57.969-71.098) compared to the H-IDO-1 group (43.74 &plusmn; 4.36) in months, (95% CI: 35.218-52.330) (p&lt; 0.05).</p>. <p>IDO-1 expression is an in&shy;de&shy;pendent prognostic biomarker to predict&nbsp;<br>OS and progression in HGG. IDO-1 can be&nbsp;evaluated as an alternative instrument for precision medicine in the treatment of gliomas.</p>.

Risk of Subsequent Neoplasms in Childhood Cancer Survivors After Radiation Therapy: A PENTEC Comprehensive Review

A Pediatric Normal Tissue Effects in the Clinic (PENTEC) analysis of published investigations of central nervous system (CNS) subsequent neoplasms (SNs), subsequent sarcomas, and subsequent lung cancers in childhood cancer survivors who received radiation therapy (RT) was performed to estimate the effect of RT dose on the risk of SNs and the modification of this risk by host and treatment factors. A systematic literature review was performed to identify data published from 1975 to 2022 on SNs after prior RT in childhood cancer survivors. After abstract review, usable quantitative and qualitative data were extracted from 83 studies for CNS SNs, 118 for subsequent sarcomas, and 10 for lung SNs with 4 additional studies (3 for CNS SNs and 1 for lung SNs) later added. The incidences of SNs, RT dose, age, sex, primary cancer diagnosis, chemotherapy exposure, and latent time from primary diagnosis to SNs were extracted to assess the factors influencing risk for SNs. The excess relative ratio (ERR) for developing SNs as a function of dose was analyzed using inverse-variance weighted linear regression, and the ERR/Gy was estimated. Excess absolute risks were also calculated. The ERR/Gy for subsequent meningiomas was estimated at 0.44 (95% CI, 0.19-0.68); for malignant CNS neoplasms, 0.15 (95% CI, 0.11-0.18); for sarcomas, 0.045 (95% CI, 0.023-0.067); and for lung cancer, 0.068 (95% CI, 0.03-0.11). Younger age at time of primary diagnosis was associated with higher risk of subsequent meningioma and sarcoma, whereas no significant effect was observed for age at exposure for risk of malignant CNS neoplasm, and insufficient data were available regarding age for lung cancer. Females had a higher risk of subsequent meningioma (odds ratio, 1.46; 95% CI, 1.22-1.76; P < .0001) relative to males, whereas no statistically significant sex difference was seen in risk of malignant CNS neoplasms, sarcoma SNs, or lung SNs. There was an association between chemotherapy receipt (specifically alkylating agents and anthracyclines) and subsequent sarcoma risk, whereas there was no clear association between specific chemotherapeutic agents and risk of CNS SNs and lung SNs. This PENTEC systematic review shows a significant radiation dose-response relationship for CNS SNs, sarcomas, and lung SNs. Given the linear dose response, improved conformality around the target volume that limits the high dose volume might be a promising strategy for reducing the risk of SNs after RT. Other host- and treatment-related factors such as age and chemotherapy play a significant contributory role in the development of SNs and should be considered when estimating the risk of SNs after RT among childhood cancer survivors.

Influence of focused ultrasound on locoregional drug delivery to the brain: Potential implications for brain tumor therapy

IntroductionEfficient delivery of therapeutics across the blood-brain barrier (BBB) for the treatment of central nervous system (CNS) tumors is a major challenge to the development of safe and efficacious therapies. Locoregional drug delivery platforms offer an improved therapeutic index by achieving high drug concentrations in the target tissue with negligible systemic exposure. Intrathecal (intraventricular) [IT] and convection-enhanced delivery [CED] are two clinically relevant methods being employed for various CNS malignancies. Both of these standalone platforms suffer from passive post-administration distribution forces, sometimes limiting the desired distribution for tumor therapy. Focused ultrasound and microbubble-mediated blood-brain barrier opening (FUS-BBBO) is a recent modality used for enhanced drug delivery. It is postulated that coupling of FUS with these alternative delivery routes may provide benefits. Multimodality FUS may provide the desired ability to increase the depth of parenchymal delivery following IT administration and provide a means for contour directionality with CED. Further, the transient enhanced permeability achieved with FUS-BBBO is well established, but drug residence and transit times, important to clinical dose scheduling, have not yet been defined. The present investigation comprises two discrete studies: 1. Conduct a comprehensive quantitative evaluation to elucidate the effect of FUS-BBBO as it relates to varying routes of administration (IT and IV) in its capacity to facilitate drug penetration within the striatal-thalamic region. 2. Investigate the impact of combining FUS-BBBO with CED on drug distribution, with a specific focus on the temporal dynamics of drug retention within the target region. MethodsFirstly, we quantitatively assessed how FUS-BBBO coupled with IT and IV altered fluorescent dye (Dextran 2000 kDa and 70 kDa) distribution and concentration in a predetermined striatal-thalamic region in naïve mice. Secondly, we analyzed the pharmacokinetic effects of using FUS mediated BBB disruption coupled with CED by measuring the volume of distribution and time-dependent concentration of the dye. ResultsOur results indicate that IV administration coupled with FUS-BBBO successfully enhances delivery of dye into the pre-defined sonication targets. Conversely, measurable dye in the sonication target was consistently less after IT administration. FUS enhances the distribution volume of dye after CED. Furthermore, a shorter time of residence was observed when CED was coupled with FUS-BBBO application when compared to CED alone. Conclusion1. Based on our findings, IV delivery coupled with FUS-BBBO is a more efficient means for delivery to deep targets (i.e. striatal-thalamic region) within a predefined spatial conformation compared to IT administration. 2. FUS-BBBO increases the volume of distribution (Vd) of dye after CED administration, but results in a shorter time of residence. Whether this finding is reproducible with other classes of agents (e.g., cytotoxic agents, antibodies, viral particles, cellular therapies) needs to be studied.

Mitigating Radiotoxicity in the Central Nervous System: Role of Proton Therapy.

Central nervous system (CNS) radiotoxicity remains a challenge in neuro-oncology. Dose distribution advantages of protons over photons have prompted increased use of brain-directed proton therapy. While well-recognized among pediatric populations, the benefit of proton therapy among adults with CNS malignancies remains controversial. We herein discuss the role of protons in mitigating late CNS radiotoxicities in adult patients. Despite limited clinical trials, evidence suggests toxicity profile advantages of protons over conventional radiotherapy, including retention of neurocognitive function and brain volume. Modelling studies predict superior dose conformality of protons versus state-of-the-art photon techniques reduces late radiogenic vasculopathies, endocrinopathies, and malignancies. Conversely, potentially higher brain tissue necrosis rates following proton therapy highlight a need to resolve uncertainties surrounding the impact of variable biological effectiveness of protons on dose distribution. Clinical trials comparing best photon and particle-based therapy are underway to establish whether protons substantially improve long-term treatment-related outcomes in adults with CNS malignancies.

From Homeostasis to Pathology: Decoding the Multifaceted Impact of Aquaporins in the Central Nervous System.

Aquaporins (AQPs), integral membrane proteins facilitating selective water and solute transport across cell membranes, have been the focus of extensive research over the past few decades. Particularly noteworthy is their role in maintaining cellular homeostasis and fluid balance in neural compartments, as dysregulated AQP expression is implicated in various degenerative and acute brain pathologies. This article provides an exhaustive review on the evolutionary history, molecular classification, and physiological relevance of aquaporins, emphasizing their significance in the central nervous system (CNS). The paper journeys through the early studies of water transport to the groundbreaking discovery of Aquaporin 1, charting the molecular intricacies that make AQPs unique. It delves into AQP distribution in mammalian systems, detailing their selective permeability through permeability assays. The article provides an in-depth exploration of AQP4 and AQP1 in the brain, examining their contribution to fluid homeostasis. Furthermore, it elucidates the interplay between AQPs and the glymphatic system, a critical framework for waste clearance and fluid balance in the brain. The dysregulation of AQP-mediated processes in this system hints at a strong association with neurodegenerative disorders such as Parkinson's Disease, idiopathic normal pressure hydrocephalus, and Alzheimer's Disease. This relationship is further explored in the context of acute cerebral events such as stroke and autoimmune conditions such as neuromyelitis optica (NMO). Moreover, the article scrutinizes AQPs at the intersection of oncology and neurology, exploring their role in tumorigenesis, cell migration, invasiveness, and angiogenesis. Lastly, the article outlines emerging aquaporin-targeted therapies, offering a glimpse into future directions in combatting CNS malignancies and neurodegenerative diseases.

LONG-TERM POST-MARKETING SURVEILLANCE DATA FROM ELDERLY PATIENTS WITH CENTRAL NERVOUS SYSTEM MALIGNANCIES TREATED WITH TUMOR TREATING FIELDS (TTFIELDS) THERAPY

Abstract AIMS Glioblastoma (GBM) has a poor prognosis, which is compounded by an increase in treatment-related toxicity with age. TTFields are electric fields that exert physical forces to disrupt cellular processes critical for cancer cell viability. Subgroup analysis of the phase 3 EF-14 study demonstrated TTFields therapy to be well-tolerated in patients ≥65 years with newly diagnosed (nd) GBM. We report safety data in elderly patients from a global post- marketing surveillance (PMS) analysis of patients with central nervous system (CNS) malignancies receiving TTFields. METHOD PMS data was collected from patients receiving TTFields (October 2011–March 2022) in North America, Europe, Middle East, Africa, and Japan. Adverse events (AEs) were categorized using MedDRA version 25.1. RESULTS Overall, 25,898 patients were included (diagnoses: ndGBM [68%], recurrent GBM [26%], anaplastic astrocytoma/oligodendroglioma [4%], other [2%]). Of these, 7808 patients (30%) were elderly (&amp;gt;65 years). 75% of elderly patients experienced ≥1 AE, with 57% related to TTFields; comparable frequencies to the overall population (73% and 56%, respectively). The most common treatment-related AE in elderly patients was skin reaction (45%; overall population: 43%). Incidence of treatment-related fall and fracture in elderly patients was 1% and &amp;lt;1%, respectively. Incidence of treatment-related ‘quality-of-life decreased’ was 2% (elderly and overall). No systemic toxicities were reported, regardless of age group. CONCLUSIONS These real-world data demonstrate TTFields has a tolerable safety profile in elderly patients with CNS malignancies, consistent with elderly subgroup data from EF-14, and with no new safety signals. Most AEs were localised, manageable, mild–moderate skin reactions.

The course of health-related quality of life after the diagnosis of childhood cancer: a national cohort study

BackgroundComprehensive insight in the longitudinal development of health-related quality of life (HRQOL) after childhood cancer diagnosis could improve quality of care. Thus, we aimed to study the course and biopsychosocial determinants of HRQOL in a unique national cohort of children with cancer.MethodsHRQOL of 2154 children with cancer was longitudinally reported (median: 3 reports) between diagnosis and 5 years after, using the pediatric quality of life inventory generic core scales (PedsQL). HRQOL was modelled over time since diagnosis using mixed model analysis for children 2–7 years (caregiver-reports) and ≥ 8 years (self-reports). Differences in the course between hematological, solid and central nervous system malignancies were studied. Additional associations of demographics, disease characteristics (age at diagnosis, relapse, diagnosis after the national centralization of childhood cancer care and treatment components) and caregiver distress (Distress thermometer) were studied.ResultsOverall, HRQOL improved with time since diagnosis, mostly in the first years. The course of HRQOL differed between diagnostic groups. In children aged 2–7 years, children with a solid tumor had most favorable HRQOL. In children aged ≥ 8 years, those with a hematological malignancy had lower HRQOL around diagnosis, but stronger improvement over time than the other diagnostic groups. In both age-groups, the course of HRQOL of children with a CNS tumor showed little or no improvement. Small to moderate associations (β: 0.18 to 0.67, p < 0.05) with disease characteristics were found. Centralized care related to better HRQOL (β: 0.25 to 0.44, p < 0.05). Caregiver distress was most consistently associated with worse HRQOL (β: − 0.13 to − 0.48, p < 0.01).ConclusionsThe HRQOL course presented can aid in identifying children who have not fully recovered their HRQOL following cancer diagnosis, enabling early recognition of the issue. Future research should focus on ways to support children, especially those with a CNS tumor, for example by decreasing distress in their caregivers.

P20.13.A AUTOGRAFTED HUMAN CORTICAL SLICE MODEL REVEALS MESENCHYMAL-LIKE TRANSITION IN BRAF-MUTATED GLIOBLASTOMA UNDER TARGETED THERAPY

Abstract BACKGROUND The emergence of personalized therapy, which targets oncogenic drivers, has provided a novel adjunct to the standard-of-care therapy for glioblastoma, the most common central nervous system malignancy. Among the less frequently observed oncogenic drivers in glioblastoma are mutations in the proto-oncogene B-Raf. Although treatment options for BRAF-mutated malignancies have been extensively investigated, the implications of BRAF and MEK inhibition in gliomas remain ambiguous. In this study, we present a model system designed to predict cellular temporal trajectories, employing human neocortical slice models and patient-derived tumor cells, coupled with spatially resolved and single-cell transcriptomic analyses for comprehensive computational modeling. MATERIAL AND METHODS Non-neoplastic cortical tissue was procured from a BRAF(V600E) mutant glioblastoma patient during surgical intervention. The tissue was sectioned and inoculated with autologous glioblastoma cells to establish an ex-vivo personalized brain slice model. To facilitate adequate tumor growth, slices were cultured for seven days with clinically approved BRAF/MEK inhibitors and respective controls. For high-dimensional analysis, the tumor specimen and slices in all treatment conditions were profiled using live cell imaging, spatially resolved transcriptomics (Visium 10X) and single nucleus RNA-sequencing (10X). Advanced computational modeling techniques, encompassing graph neural networks and single-cell deconvolution, were employed to scrutinize the spatio-temporal evolution of the tumor and its microenvironment. RESULTS Live cell imaging showed varied treatment responses in tumor growth during culture. Immunofluorescence and immunohistochemistry analyses (using NeuN, GFAP, and Iba-1 cell markers) indicated no toxic effects from drug combinations on the tumor microenvironment. Single nucleus profiling revealed a tumoral trajectory towards induction of mesenchymal-like transcriptional programs under BRAF/MEK inhibition along with up-regulation of alternative receptor tyrosine kinases such as HER2/3 and EGFR. Spatial projection of single cell trajectories using cytospace confirmed the escape mechanism of BRAF/MEK inhibition due to acquisition of anti-inflammatory myeloid cells in close proximity to the tumor niches and enhancement of mesenchymal transcriptional programs. In line with the experimental set-up, we observed a rapid progression of the tumor und BRAF/MEK inhibition in the patient. CONCLUSION Our reported model system, employing high-dimensional readouts and advanced computational modeling, showcases a promising avenue to address uncertainties in personalized medicine, emphasizing that conventional oncological drivers may necessitate alternative treatment strategies in central nervous system malignancies.

PL02.1.A DELINEATING AND TARGETING A NOVEL METABOLISM-BASED POST-TRANSLATIONAL MECHANISM REGULATING THE ABUNDANCE OF THE ‘UNDRUGGABLE’ ONCOPROTEIN C-MYC IN MEDULLOBLASTOMA

Abstract BACKGROUND Brain tumors are the leading cause of cancer death in children, and medulloblastoma (MB) is one of the most common pediatric central nervous system malignancies. Amplification of the c-MYC oncogene is frequently observed in the most aggressive and lethal subgroup of this disease, group 3 (G3), but not in other subgroups. Patients that have G3 MB tumors with high c-MYC abundance are more likely to present as metastatic and are prone to develop fatal recurrent tumors. Unfortunately, the functional ubiquity and disordered structure of c-MYC makes it difficult to target for cancer treatment. Therefore, it is critical to identify novel, out-of-the-box strategies to suppress oncogenic c-MYC in highly aggressive G3 MB brain tumors. Recently, metabolism has emerged as a major regulator of overall cellular signaling processes through post-translational and epigenetic mechanisms. While c-MYC is known to regulate cellular metabolism, whether metabolism plays a role in reciprocally supporting enhanced c-MYC abundance in cancer is unknown. We hypothesize that an intrinsic feedback mechanism may exist where metabolic activity modulates c-MYC abundance that could be exploited as a therapeutic strategy to improve outcomes for G3 MB patients. MATERIAL AND METHODS Using various well-characterized G3 MB cells, patient-derived G3 MB cells, orthotopic intracerebellar xenograft models, patient tumor bioinformatics, detailed biochemical characterization, and point-mutation analyses, we have identified a novel metabolism-dependent post-translational modification that regulates c-MYC stability in G3 MB. RESULTS In-depth molecular analyses unveiled that c-MYC is susceptible to oxidation and proteasomal degradation under conditions of metabolic stress. Targeting mitochondrial respiration via inhibition of complex-I promotes the accumulation of reactive oxygen species (ROS) and leads to rapid cysteine oxidation and proteasomal degradation of c-MYC in G3 MB cells, but not normal human brain astrocytes or neural stem cells (NSCs). Point mutation analysis combined with biochemical oxidation assays identified the specific cysteine residues of c-MYC that are susceptible to oxidation and ultimately responsible for enhanced c-MYC degradation following complex-I inhibition. Importantly, oral administration of a blood-brain barrier permeable complex-I inhibitor impaired the growth of intracerebellar MB xenograft tumors in mice, significantly prolonging animal survival. CONCLUSION Altogether, these findings unveil a novel mechanism through which metabolism regulates the post-translational stability of c-MYC and provides insights for designing rationale therapeutic strategies for the treatment of MB patients. SUPPORT This work is supported by a project grant from the Canadian Institutes of Health Research (CIHR).

Brain Tumor Classification using Transfer Learning

Brain tumors are one of the more severe medical conditions that can affect both children and adults. Brain tumors make up between 85 and 90 percent of all primary Central Nervous System (CNS) malignancies. Each year, brain tumors are found in about 11,700 persons. The 5-year survival rate is around 34% for males and 36% for female patients with malignant brain or CNS tumors. Brain tumors can be classified as benign, malignant, pituitary, and other forms. Appropriate treatment, meticulous planning, and exact diagnostics must be used to prolong patient lives. The most reliable way for detecting brain cancer is Magnetic Resonance Imaging (MRI). The images are examined by the radiologist. As brain tumors are complex the MRI serve as guide to diagnose the seriousness of the disease. Since the placement and size of the brain tumor seems incredibly abnormal for persons affected by the disease it becomes difficult to properly comprehend the nature of the tumor. For MRI analysis, a qualified neurosurgeon is also necessary. Compiling the results of an MRI can be extremely difficult and time-consuming because there are typically not enough qualified medical professionals and individuals who are knowledgeable about malignancy in poor countries. Thus, this issue can be resolved by an automated cloud-based solution. In the proposed model, The Convolutional Neural Networks (CNN) is used for the classification of the brain tumor dataset with an accuracy of 99%.

Survival Benefit from Multimodal Treatment for Patients with Atypical Teratoid Rhabdoid Tumor in a Surveillance, Epidemiology, and End Results Database Analysis

Introduction: Atypical teratoid rhabdoid tumor (ATRT) is among the most aggressive central nervous system malignancies. Although rare, this tumor typically afflicts young children and results in mortality within months. Here, we aim to determine key clinical features and treatment options that impact the survival of patients with ATRT. Methods: From the year 2000 to 2019, 363 patients with ATRT were identified from the Surveillance, Epidemiology, and End Results database. Univariate analysis was used to identify variables that had a significant impact on the primary endpoint of overall survival (OS). Multivariable analysis was then used to identify independent predictors of survival. Results: The median OS of the entire cohort was 13 months. Univariate analysis identified ages between 1 and 3 years, ages between 4 and 17 years, years of diagnosis between 2010 and 2019, and the receipt of treatment to have a significant impact on survival. In multivariable analysis, ages between 1 and 3 years and receipt of treatment were the only significant independent predictors of survival. The median OS was significantly greater in patients who received surgical treatment, chemotherapy, or radiation when compared to those who did not receive any treatment. In general, the receipt of any combination of therapies improved the median OS significantly. The receipt of triple therapy had the greatest impact on survival. Discussion: This study highlights the survival benefit of a multimodal approach in the treatment of ATRT. The use of triple therapy, including surgery, radiation, and chemotherapy, was found to have the greatest survival benefit for patients. Overall, these findings may guide future care for patients with ATRT.