Biology and management of ependymomas

Oncohistone-sculpted epigenetic mechanisms in pediatric brain cancer

Chromatin dynamics, involving reversible changes in chromatin structure, shape key cellular processes and genomic integrity during development and proliferation, with disruptions leading to cancer. Histones, core components of chromatin and substrates for chromatin-modifying enzymes, play crucial roles in oncogenesis when misregulated or mutated. This is particularly pronounced in pediatric hind brain cancers, some of which are driven primarily by the oncohistone H3K27M and the recently identified oncohistone-mimic protein CXorf67/EZHIP. Notably, H3K27M and EZHIP-driven cancers exhibit low mutation burdens, highlighting the enigmatic role of non-mutational epigenetic reprogramming in oncogenesis beyond traditional paradigms of oncogene activation and tumor suppressor loss. Here, we review the impact of H3K27M and EZHIP-driven cancer mechanisms on chromatin and transcriptional dysregulation leading to aberrant cell fate determination, and their potential influence beyond gene activity, affecting broader cellular pathways. Illuminating these mechanisms is crucial for advancing treatment options for pediatric brain cancers, where therapeutic regimens are poorly defined.

Cross-Talk Between Cancer and Its Cellular Environment-A Role in Cancer Progression

The tumor microenvironment is a dynamic and complex three-dimensional network comprising the extracellular matrix and diverse non-cancerous cells, including fibroblasts, adipocytes, endothelial cells and various immune cells (lymphocytes T and B, NK cells, dendritic cells, monocytes/macrophages, myeloid-derived suppressor cells, and innate lymphoid cells). A constantly and rapidly growing number of studies highlight the critical role of these cells in shaping cancer survival, metastatic potential and therapy resistance. This review provides a synthesis of current knowledge on the modulating role of the cellular microenvironment in cancer progression and response to treatment.

Evaluating the safety and efficacy of proton radiotherapy for intracranial pediatric ependymomas: A single-arm meta-analysis

BACKGROUND

Ependymomas account for 6% to 10% of childhood central nervous system tumors. This study aimed to evaluate the safety and efficacy of proton radiotherapy in intracranial ependymoma patients.

METHODS

We performed a systematic review and single-arm meta-analysis. We searched Medline, Embase, Cochrane, and Web of Science for eligible trials. Random-effects model was used to calculate the risk ratios (RRs), with 95% confidence intervals (CIs). Statistical analyses were performed using RStudio version 4.2.3.

RESULTS

Ten cohorts comprising 908 patients with ependymoma were included. The patient population had an average age of 3.5 years, and 53.4 % were male. In terms of proportion, nine outcomes were analyzed: 3-year Progression-Free Survival (PFS; Proportion = 0.63; 95 % CI [0.40-0.87]; I2 = 95 %), 5-year Local Control (LC; Proportion = 0.79; 95 % CI [0.69-0.90]; I2 = 85 %), 5-year Event-Free Survival (EFS; Proportion = 0.65; 95 % CI [0.52-0.78]; I2 = 95 %), 5-year Overall Survival (OS; Proportion = 0.83; 95 % CI [0.77-0.90]; I2 = 82 %), 2-year OS (Proportion = 0.91; 95 % CI [0.88-0.94]; I2 = 0 %), 3-year OS (Proportion = 0.92; 95 % CI [0.89;0.95]; I2 = 43 %). Additionally, neurological (Proportion = 0.17; 95 % CI [0.07-0.27]; I2 = 97 %), dermatological (Proportion = 0.20; 95 % CI [0.00-0.44]; I2 = 82 %), and brainstem complications (Proportion = 0.03; 95 % CI [0.01-0.04]; I2 = 31 %) were investigated.

CONCLUSION

While proton radiotherapy appears safe and effective based on current data, these results should be approached cautiously, as broad confidence intervals in some adverse event rates suggest variability in outcomes.

Intradural extramedullary double primary ependymoma and meningioma rare condition: Case report and literature review

RATIONALE

Ependymomas are commonly prevalent intramedullary neoplasms in adults, with hardly any cases of exophytic extramedullary ependymoma being reported. Meningiomas, on the contrary, are one of the most common intradural extramedullary (IDEM) tumors. However, the occurrence of both IDEM tumors simultaneously is extremely rare.

PATIENT CONCERNS

A 63-year-old female who presented with pain and numbness in both lower limbs, and symptoms rapidly progressed over the past 5 months.

DIAGNOSIS

Based on the patient's clinical symptoms and imaging features, we conducted pathological examination and genetic testing, ultimately confirming that the patient had IDEM double primary ependymoma and meningioma.

INTERVENTIONS

Surgery was performed to remove double spinal tumors, decompress spinal nerve roots, and perform laminectomy, and she was treated with electrocardiogram monitoring, antibiotics, hemostasis, and antiedema therapy.

OUTCOMES

Histopathology confirmed World Health Organization grade II ependymoma at L2 and World Health Organization grade I meningioma at T12-L1. MYCN amplification and other genetic alterations were absent. Postoperative recovery was favorable, with no recurrence at 6-month follow-up.

LESSONS

This is the first reported case of IDEM double primary ependymoma and meningioma, highlighting the rarity of such cases and the importance of thorough diagnostic workup and surgical excision for IDEM tumors. Genetic analysis adds to the understanding of these rare tumors and guides management strategies.

Clinicopathological profile of ependymomas with special reference to survival data - Experiences of a tertiary care center'

BACKGROUND AND AIMS

Ependymomas exhibit heterogeneity across age, location, histology, molecular nature and survival suggestive of an epigenetic component in its pathogenesis. The CNS WHO classification (2021) classifies ependymomas based on DNA methylation profiles. Studies suggest that molecular sub-types remain stable throughout the course of disease. Immunohistochemical expression of L1CAM, has been identified as a surrogate marker for ZFTA/c11orf95-RELA fusion in supratentorial ependymomas. This study aims at realising its utility specially in resource-poor setups.

MATERIALS AND METHODS

Forty-three histopathologically-proven cases of ependymoma under treatment over the period of three years were selected. Histopathological examination followed by routine IHC staining for GFAP, S-100, EMA and Ki-67 in all cases and L1CAM in the supratentorial ependymomas was done. We have followed-up almost all cases during our study period and was correlated with the IHC expression patterns and clinico-pathological parameters, including survival.

RESULTS

In our study the commonest location for ependymomas was spine in adults and posterior fossa in pediatric age group. Majority cases belonged to CNS WHO Grade 2 both in adults and in the paediatric age group. Supratentorial location of ependymomas with positive immuno-reactivity for L1CAM and a higher Ki-67 labelling index were associated with poor survival.

CONCLUSION

Our study revealed that L1CAM is an effective surrogate marker for supratentorial ependymomas possibly carrying the ZFTA Fusion gene product. The L1CAM immuno-reactivity also corresponded with the survival data. However, larger population-based studies are required to validate these results further.

Liquid Biopsy for Spinal Tumors: On the Frontiers of Clinical Application

STUDY DESIGN

Narrative review.

OBJECTIVES

This article aims to provide a narrative review of the current state of research for liquid biopsy in spinal tumors and to discuss the potential application of liquid biopsy in the clinical management of patients with spinal tumors.

METHODS

A comprehensive review of the literature was performed using PubMed, Google Scholar, Medline, Embase and Cochrane databases, and the review was limited to articles of English language. All the relevant articles which were identified to be related to liquid biomarker study in spinal tumors, were studied in full text.

RESULTS

Liquid biopsy has revolutionized the field of precision medicine by guiding personalized clinical management of cancer patients based on the liquid biomarker status. In recent years, more research has been done to investigate its potential utilization in patients with tumors from the spine. Herein, we review the liquid biomarkers that have been proposed in different spine malignancies including chordoma, chondrosarcoma, Ewing sarcoma, osteosarcoma, astrocytoma and ependymoma. We also discuss the wide window of opportunity to utilize these liquid biomarkers in diagnosis, treatment response, monitoring, and detection of minimal residual disease in patients with spinal tumors.

CONCLUSIONS

Liquid biomarkers, especially blood-derived circulating tumor DNA, has a promising clinical utility as they are disease-specific, minimally invasive, and the procedure is repeatable. Prospective studies with larger populations are needed to fully establish its use in the setting of spinal tumors.

Intracranial ependymoma: A retrospective analysis of clinical features, treatment modalities, and long-term outcome

Objective

Ependymomas, rare neuroglial tumors originating from ependymal cells, can occur in the CNS and typically affect the brain's ventricles or spinal cord. Prognosis is influenced by tumor grade, location, resection extent, and preoperative Karnofsky Performance Status Scale (KPSS) scores. This study evaluates clinical features, treatment outcomes, and factors affecting prognosis in patients with intracranial ependymomas.

Methods

A retrospective review of 23 patients with intracranial ependymomas, treated from 2018 to 2023, was conducted. Data included demographics, clinical presentations, KPSS scores, imaging findings, and treatment details. Outcomes assessed were postoperative complications, recurrence rates, and functional status. Statistical analysis used SPSS version 26, with significance set at p < 0.05.

Results

The cohort was predominantly male (87.0%), with a mean age of 27 years. Tumors were mostly in the fourth ventricle (82.6%), with an average diameter of 68.9 mm. Complete resection was achieved in 87.0% of cases. Postoperative radiotherapy was given to 91.0% of grade 2 and all grade 3 tumors. Recurrence occurred in 17.4% of grade 2 ependymomas, but none of grade 3. The seven-month mortality rate was 4.3%. Higher preoperative KPSS scores correlated with better outcomes.

Conclusion

Complete tumor resection and postoperative radiotherapy are crucial for improved outcomes in ependymomas. Higher preoperative KPSS scores and tumor location significantly impact prognosis. Tumors in the lateral ventricles are associated with higher recurrence risks. These findings highlight the need for aggressive surgical management and personalized adjuvant therapy to enhance patient outcomes.

The intersection of race, ethnicity, and urbanicity on treatment paradigms and clinical outcomes for non-malignant primary tumors of the spine

BACKGROUND

Non-malignant primary tumors of the spine (NMPTS) patients in rural areas face unique barriers that may limit their capacity to receive optimal care. With a lower geographical distribution of neurosurgical specialists and limited healthcare infrastructure, rural NMPTS patients may receive certain treatments at a lower frequency than metropolitan patients. NMPTS We sought to examine the association between residential urbanicity, race-ethnicity, treatment patterns, and survival outcomes for cases diagnosed with NMPTS.

METHODS

Cases of NMPTS diagnosed between 2004 and 2019 were identified from the Central Brain Tumor Registry of the United States (CBTRUS), a combined dataset of CDC's National Program of Cancer Registries (NPCR) and NCI's Surveillance, Epidemiology and End Results (SEER) data. Using multivariable logistic regression, we evaluated the association between urbanicity and treatment (including surgery and radiation), adjusted for age at diagnosis, sex, and race-ethnicity. Patient-level all-cause survival data were obtained from the NPCR Survival Analytical Database (2004-2018).

RESULTS

A total of 38,414 cases were identified, 33,097 of whom lived in metropolitan and 5317 of whom lived in non-metropolitan regions. Nerve sheath tumors and meningiomas were the most common tumor histopathologies across both regions, with no clinically significant difference in other histopathologies (p<0.001). There were statistically significant differences between the frequency and type of surgery received by urbanicity (p<0.001). Overall all-cause survival was significantly lower for NH Blacks residing in non-metropolitan areas when compared to NH Blacks residing in metropolitan areas (p<0.0001).

CONCLUSION

Our data demonstrates significant differences in the incidence of NMPTS across both race-ethnicity and urbanicity. However, a wider analysis of all-cause mortality reveals disparities in health outcomes across both race-ethnicity and urbanicity for Black and Hispanic populations. To address the disparity in health outcomes, policymakers and health providers need to work with local communities in rural areas to improve access to equitable and quality healthcare.

Clustering-independent estimation of cell abundances in bulk tissues using single-cell RNA-seq data

Single-cell RNA sequencing has transformed the study of biological tissues by enabling transcriptomic characterizations of their constituent cell states. Computational methods for gene expression deconvolution use this information to infer the cell composition of related tissues profiled at the bulk level. However, current deconvolution methods are restricted to discrete cell types and have limited power to make inferences about continuous cellular processes such as cell differentiation or immune cell activation. We present ConDecon, a clustering-independent method for inferring the likelihood for each cell in a single-cell dataset to be present in a bulk tissue. ConDecon represents an improvement in phenotypic resolution and functionality with respect to regression-based methods. Using ConDecon, we discover the implication of neurodegenerative microglia inflammatory pathways in the mesenchymal transformation of pediatric ependymoma and characterize their spatial trajectories of activation. The generality of this approach enables the deconvolution of other data modalities, such as bulk ATAC-seq data.

Clinical, magnetic resonance imaging, histopathological features, treatment options and outcome of spinal ependymoma in dogs: 8 cases (2011-2022)

OBJECTIVES

This study aims to report on the clinical magnetic resonance imaging, histological features, treatment options and outcomes of spinal ependymomas in dogs.

MATERIALS AND METHODS

Retrospective evaluation of medical records from dogs histologically confirmed spinal ependymomas with clinical presentations, magnetic resonance imaging findings, histological aspects, treatment options and outcomes.

RESULTS

Eight dogs presented with acute to subacute onset of para- or tetraparesis. Magnetic resonance imaging findings included intramedullary oval-shaped space-occupying lesions that appeared hyperintense on T2-weighted images isointense on T1-weighted images and exhibited marked homogeneous or ring contrast enhancement. A peculiar feature, previously described only in human ependymomas, was observed in three patients - a T2-weighted hypointense rim, termed hemosiderin cap sign. Haematomyelia with necrotic foci was observed in one dog. Surgery, when performed, enabling a definitive intra-vitam diagnosis. Histological examination revealed that rosettes and pseudo-rosettes as disposition of neoplastic cells were the most common features reported. Furthermore, cerebrospinal fluid metastases were identified in one case.

CLINICAL SIGNIFICANCE

Clinical and histopathological findings in our case series were consistent with those previously reported in the literature. Magnetic resonance imaging features were fairly typical and highly suggestive of spinal ependymomas. The hemosiderin cap sign may aid in the presumptive intra-vitam diagnosis of these rare spinal tumours. Additionally, we described cerebrospinal fluid spread of neoplastic cells and subsequent multifocal or metastasis presentations. Surgery offered a dual benefit by facilitating intra-vitam diagnosis and, in some cases, extending survival time.

Clustering-independent estimation of cell abundances in bulk tissues using single-cell RNA-seq data

Single-cell RNA-sequencing has transformed the study of biological tissues by enabling transcriptomic characterizations of their constituent cell states. Computational methods for gene expression deconvolution use this information to infer the cell composition of related tissues profiled at the bulk level. However, current deconvolution methods are restricted to discrete cell types and have limited power to make inferences about continuous cellular processes like cell differentiation or immune cell activation. We present ConDecon, a clustering-independent method for inferring the likelihood for each cell in a single-cell dataset to be present in a bulk tissue. ConDecon represents an improvement in phenotypic resolution and functionality with respect to regression-based methods. Using ConDecon, we discover the implication of neurodegenerative microglia inflammatory pathways in the mesenchymal transformation of pediatric ependymoma and characterize their spatial trajectories of activation. The generality of this approach enables the deconvolution of other data modalities such as bulk ATAC-seq data.

Conditional survival estimates for ependymomas reveal the dynamic nature of prognostication

BACKGROUND

Traditional survival analysis is frequently used to assess the prognosis of ependymomas (EPNs); however, it may not provide additional survival insights for patients who have survived for several years. Thus, the conditional survival (CS) pattern of this disease is yet to be further investigated. This study aimed to evaluate the improvement of survival over time using CS analysis and develop a CS-based nomogram model for real-time dynamic survival estimation for EPN patients.

METHODS

Data on patients with EPN were collected from the Surveillance, Epidemiology, and End Results (SEER) database. In order to construct and validate the model effectively, the selected patients were randomly divided at 7:3 ratio. CS is defined as the probability of surviving for a specified time period (y years) after initial diagnosis, given that the patient has survived x years. The CS pattern of EPN patients were explored. Then, the least absolute shrinkage and selection operator (LASSO) regression method with tenfold cross-validation was employed to identify prognostic predictors. Multivariate Cox regression was employed to develop a CS-based nomogram model, and we used this model to quantify EPN patient risk. Finally, the performance of the prediction model was also evaluated and verified.

RESULTS

In total, 1829 patients diagnosed with EPN were included in the study, with 1280 and 549 patients in the training and validation cohorts, respectively. The CS analysis demonstrated that patients' OS saw gradual improvements over time. With each additional year of survival post-diagnosis, the 10-year survival rate of EPN patients saw an increase, updating from 74% initially to 79%, 82%, 85%, 87%, 89%, 91%, 93%, 96%, and 98% (after surviving for 1-9 years, respectively). The LASSO regression model, which implements tenfold cross-validation, identified 7 significant predictors (age, tumor grade, tumor site, tumor extension, tumor size, surgery and radiotherapy) to develop a CS-based nomogram model. And further risk stratification was conducted based on nomogram model for these patients. Furthermore, this survival prediction model was successfully validated.

CONCLUSION

This study described the CS pattern of EPN patients and highlighted the gradual improvement of survival observed over time for long-term survivors. We also developed the first novel CS-nomogram model that enabled individualized and real-time prognosis prediction. But patients must be counselled that individual circumstances may not always accurately reflect the findings of the nomogram.

Machine learning-based nomogram for distinguishing between supratentorial extraventricular ependymoma and supratentorial glioblastoma

Objective

To develop a machine learning-based nomogram for distinguishing between supratentorial extraventricular ependymoma (STEE) and supratentorial glioblastoma (GBM).

Methods

We conducted a retrospective analysis on MRI datasets obtained from 140 patients who were diagnosed with STEE (n=48) and GBM (n=92) from two institutions. Initially, we compared seven different machine learning algorithms to determine the most suitable signature (rad-score). Subsequently, univariate and multivariate logistic regression analyses were performed to identify significant clinical predictors that can differentiate between STEE and GBM. Finally, we developed a nomogram by visualizing the rad-score and clinical features for clinical evaluation.

Results

The TreeBagger (TB) outperformed the other six algorithms, yielding the best diagnostic efficacy in differentiating STEE from GBM, with area under the curve (AUC) values of 0.735 (95% CI: 0.625-0.845) and 0.796 (95% CI: 0.644-0.949) in the training set and test set. Furthermore, the nomogram incorporating both the rad-score and clinical variables demonstrated a robust predictive performance with an accuracy of 0.787 in the training set and 0.832 in the test set.

Conclusion

The nomogram could serve as a valuable tool for non-invasively discriminating between STEE and GBM.

Stereotactic Radiosurgery for Ependymoma in Pediatric and Adult Patients: A Single-Institution Experience

BACKGROUND AND OBJECTIVES

Ependymoma is commonly classified as World Health Organization grade 2 with the anaplastic variant categorized as grade 3. Incomplete resection or anaplastic features can result in unfavorable outcomes. Stereotactic radiosurgery (SRS) provides a minimally invasive approach for recurrent ependymomas. Our study investigates the efficacy and safety of SRS for grade 2 and 3 ependymomas in pediatric and adult populations.

METHODS

We conducted a retrospective analysis on 34 patients with 75 ependymomas after CyberKnife SRS between 1998 and 2023. Fourteen were pediatric (3-18 years), and 20 were adult (19-75 years) patients. The median age was 21 years, and the median tumor volume was 0.64 cc. The median single-fraction equivalent dose was 16.6 Gy, with SRS administered at 77% of the median isodose line.

RESULTS

After a median follow-up of 42.7 months (range: 3.8-438.3), 22.7% of ependymomas progressed. The 5-year local tumor control rate was 78.1%, varying between 59.6% and 90.2% for children and adults, with grade 2 at 85.9% compared with 58.5% for grade 3 tumors. The 5-year overall survival rate was 73.6%, notably higher in adults (94.7%) than in children (41%), and 100% for grade 2 but decreased to 35.9% for grade 3 patients. The 5-year progression-free survival rate was 68.5%, with 78.3% and 49.2% for adults and children, respectively, and a favorable 88.8% for grade 2, contrasting with 32.6% for grade 3 patients. Symptom improvement was observed in 85.3% of patients. Adverse radiation effects occurred in 21.4% of pediatric patients.

CONCLUSION

Our study supports SRS as a viable modality for pediatric and adult patients with grade 2 and 3 ependymomas. Despite lower local tumor control in pediatric and grade 3 cases, integrating SRS holds promise for improved outcomes. Emphasizing careful patient selection, personalized treatment planning, and long-term follow-up is crucial for optimal neurosurgical outcomes.

Differentiating Low-Grade from High-Grade Intracranial Ependymomas: Comparison of Dynamic Contrast-Enhanced MRI and Diffusion-Weighted Imaging

BACKGROUND AND PURPOSE

The aim of this study was to determine the diagnostic value of fractional plasma volume derived from dynamic contrast-enhanced perfusion MR imaging versus ADC, obtained from DWI in differentiating between grade 2 (low-grade) and grade 3 (high-grade) intracranial ependymomas.

MATERIALS AND METHODS

A hospital database was created for the period from January 2013 through June 2022, including patients with histologically-proved ependymoma diagnosis with available dynamic contrast-enhanced MR imaging. Both dynamic contrast-enhanced perfusion and DWI were performed on each patient using 1.5T and 3T scanners. Fractional plasma volume maps and ADC maps were calculated. ROIs were defined by a senior neuroradiologist manually by including the enhancing tumor on every section and conforming a VOI to obtain the maximum value of fractional plasma volume (Vpmax) and the minimum value of ADC (ADCmin). A Mann-Whitney U test at a significance level of corrected P = .01 was used to evaluate the differences. Additionally, receiver operating characteristic curve analysis was applied to assess the sensitivity and specificity of Vpmax and ADCmin values.

RESULTS

A total of 20 patients with ependymomas (10 grade 2 tumors and 10 grade 3 tumors) were included. Vpmax values for grade 3 ependymomas were significantly higher (P < .002) than those for grade 2. ADCmin values were overall lower in high-grade lesions. However, no statistically significant differences were found (P = .12114).

CONCLUSIONS

As a dynamic contrast-enhanced perfusion MR imaging metric, fractional plasma volume can be used as an indicator to differentiate grade 2 and grade 3 ependymomas. Dynamic contrast-enhanced perfusion MR imaging plays an important role with high diagnostic value in differentiating low- and high-grade ependymoma.

Implications of DNA Methylation Classification in Diagnosing Ependymoma

BACKGROUND

Ependymoma is a central nervous system (CNS) tumor that arises from the ependymal cells of the brain's ventricles and spinal cord. The histopathology of ependymomas is indistinguishable regardless of the site of origin, and the prognosis varies. Recent studies have revealed that the development site and prognosis reflect the genetic background. In this study, we used genome-wide DNA methylation array analysis to investigate the epigenetic background of ependymomas from different locations treated at our hospital.

METHODS

Four cases of posterior fossa ependymomas and 11 cases of spinal ependymomas were analyzed.

RESULTS

DNA methylation profiling using the DKFZ methylation classifier showed that the methylation diagnoses of the 2 cases differed from the histopathological diagnoses, and 2 cases could not be classified. Tumor that spread from the brain to the spinal cord was molecularly distinguishable from other primary spinal tumors.

CONCLUSIONS

Although adding DNA methylation classification to conventional diagnostic methods may be helpful, the diagnosis in some cases remains undetermined. This may affect decision-making regarding treatment strategies and follow-up. Further investigations are required to improve the diagnostic accuracy of these tumors.

New CNS tumor classification: The importance in pediatric neurosurgical practice

Background

The management of the central nervous system (CNS) tumors in the pediatric population is crucial in neurosurgical practice. The World Health Organization (WHO) has evolved its classification of CNS tumors from the 19th century to the 5th edition, published in 2021, incorporating molecular advancements. This transition from morphology to molecular characterization is ongoing.

Methods

This manuscript analyzes the modifications introduced in the 5th edition of WHO's CNS tumor classification, particularly focusing on pediatric tumor families. The paper integrates clinical, morphological, and molecular information, aiming to guide pediatric neurosurgeons in their daily practice and interdisciplinary discussions.

Results

The 5th edition of the WHO classification introduces a hybrid taxonomy that incorporates both molecular and histological components. The terminology shifts from "entity" to "type" and "subtype," aiming to standardize terminology. Tumor grading experiences changes, integrating molecular biomarkers for prognosis. The concept of integrated layered diagnosis is emphasized, where molecular and histological information is combined systematically.

Conclusion

The 5th edition of the WHO CNS classification signifies a paradigm shift toward molecular characterization. The incorporation of molecular advances, the layered diagnostic approach, and the inclusion of clinical, morphological, and molecular information aim to provide comprehensive insights into pediatric CNS tumors. This classification offers valuable guidance for pediatric neurosurgeons, aiding in precise diagnosis and treatment planning for these complex neoplasms.

Adolescents and Young Adults With Cancer: CNS Tumors

Tumors of CNS are common in adolescents and young adults (AYAs). As the second leading cause of cancer-related death, CNS tumors in AYAs require improved clinical management. In this review, we discussed the current diagnostic approaches and recommended management strategies for malignant tumors in adult-type (IDH-mutant gliomas) and pediatric-type gliomas (pediatric high-grade gliomas), ependymoma and medulloblastoma, which commonly occur in AYAs. The impact of advanced molecular diagnostic approaches on the understanding of tumor biology of AYA CNS tumors is emphasized. To enhance participation in clinical trials, which poses a unique challenge in AYAs with CNS tumors, we propose encouraging referrals to neuro-oncology specialty care and improving collaboration between oncologists who care for both pediatric and adult patients. This will ensure better representation of AYA patients in research studies. Finally, we discussed the importance of considering neurocognitive and psychological function in AYAs with CNS tumor.

A Fully Automated Deep-Learning Model for Predicting the Molecular Subtypes of Posterior Fossa Ependymomas Using T2-Weighted Images

PURPOSE

We aimed to develop and validate a deep learning (DL) model to automatically segment posterior fossa ependymoma (PF-EPN) and predict its molecular subtypes [Group A (PFA) and Group B (PFB)] from preoperative MR images.

EXPERIMENTAL DESIGN

We retrospectively identified 227 PF-EPNs (development and internal test sets) with available preoperative T2-weighted (T2w) MR images and molecular status to develop and test a 3D nnU-Net (referred to as T2-nnU-Net) for tumor segmentation and molecular subtype prediction. The network was externally tested using an external independent set [n = 40; subset-1 (n = 31) and subset-2 (n =9)] and prospectively enrolled cases [prospective validation set (n = 27)]. The Dice similarity coefficient was used to evaluate the segmentation performance. Receiver operating characteristic analysis for molecular subtype prediction was performed.

RESULTS

For tumor segmentation, the T2-nnU-Net achieved a Dice score of 0.94 ± 0.02 in the internal test set. For molecular subtype prediction, the T2-nnU-Net achieved an AUC of 0.93 and accuracy of 0.89 in the internal test set, an AUC of 0.99 and accuracy of 0.93 in the external test set. In the prospective validation set, the model achieved an AUC of 0.93 and an accuracy of 0.89. The predictive performance of T2-nnU-Net was superior or comparable to that of demographic and multiple radiologic features (AUCs ranging from 0.87 to 0.95).

CONCLUSIONS

A fully automated DL model was developed and validated to accurately segment PF-EPNs and predict molecular subtypes using only T2w MR images, which could help in clinical decision-making.

Recurrent intracranial anaplastic ependymoma with late-onset giant scalp metastasis

Key Clinical Message

Ependymomas are primary brain tumors that predominantly affect individuals between 0 and 4 years of age. Although ependymomas have a propensity for recurrence and the potential to spread within the central nervous system through cerebrospinal fluid (resulting in drop metastases), reports of extra-neural metastatic localizations are exceedingly rare in the existing literature. This case report presents a unique and rare instance of recurrent intracranial anaplastic ependymoma with a late-onset giant scalp metastasis.

Abstract

A 55-year-old male patient with a medical history of partial resection of an atypical supratentorial left temporal ependymoma presented with a recurrent anaplastic ependymoma, which had been managed with surgery and radiotherapy. After a 4-year follow-up, the patient developed a subcutaneous mass in the left parietal region of the scalp. A multidisciplinary team of neurosurgeons and plastic surgeons performed a surgical procedure, which included en bloc removal of the scalp lesion, resection of 1 cm of unaffected skin, and craniotomy to address an osteolytic area in the parietal skull bone. Skin autografts were used for reconstruction. Histological examination confirmed metastasis of anaplastic ependymoma in the scalp. After a delay in starting chemotherapy due to concerns related to the COVID-19 pandemic, the patient eventually initiated chemotherapy, leading to disease stability at a short-term follow-up. Scalp metastases from ependymoma are rarely reported in the literature. Management of such cases necessitates aggressive surgical resection, followed by adjuvant chemotherapy and radiotherapy. A multidisciplinary approach is recommended to ensure effective and targeted therapy, with a focus on preserving aesthetics, particularly in pediatric cases.

"Soap bubble" sign as an imaging marker for posterior fossa ependymoma Group B

PURPOSE

To investigate the predictive value of the "soap bubble" sign on molecular subtypes (Group A [PFA] and Group B [PFB]) of posterior fossa ependymomas (PF-EPNs).

METHODS

MRI scans of 227 PF-EPNs (internal retrospective discovery set) were evaluated by two independent neuroradiologists to assess the "soap bubble" sign, which was defined as clusters of cysts of various sizes that look like "soap bubbles" on T2-weighted images. Two independent cohorts (external validation set [n = 31] and prospective validation set [n = 27]) were collected to validate the "soap bubble" sign.

RESULTS

Across three datasets, the "soap bubble" sign was observed in 21 PFB cases (7.4% [21/285] of PF-EPNs and 12.9% [21/163] of PFB); none in PFA. Analysis of the internal retrospective discovery set demonstrated substantial interrater agreement (1st Rating: κ = 0.71 [0.53-0.90], 2nd Rating: κ = 0.83 [0.68-0.98]) and intrarater agreement (Rater 1: κ = 0.73 [0.55-0.91], Rater 2: κ = 0.74 [0.55-0.92]) for the "soap bubble" sign; all 13 cases positive for the "soap bubble" sign were PFB (p = 0.002; positive predictive value [PPV] = 100%, negative predictive value [NPV] = 44%, sensitivity = 10%, specificity = 100%). The findings from the external validation set and the prospective validation set were similar, all cases positive for the "soap bubble" sign were PFB (p < 0.001; PPV = 100%).

CONCLUSION

The "soap bubble" sign represents a highly specific imaging marker for the PFB molecular subtype of PF-EPNs.

Study of lncRNAs in Pediatric Neurological Diseases: Methods, Analysis of the State-of-Art and Possible Therapeutic Implications

Long non-coding RNAs (lncRNAs) have emerged as crucial regulators in various cellular processes, and their roles in pediatric neurological diseases are increasingly being explored. This review provides an overview of lncRNA implications in the central nervous system, both in its physiological state and when a pathological condition is present. We describe the role of lncRNAs in neural development, highlighting their significance in processes such as neural stem cell proliferation, differentiation, and synaptogenesis. Dysregulation of specific lncRNAs is associated with multiple pediatric neurological diseases, such as neurodevelopmental or neurodegenerative disorders and brain tumors. The collected evidence indicates that there is a need for further research to uncover the full spectrum of lncRNA involvement in pediatric neurological diseases and brain tumors. While challenges exist, ongoing advancements in technology and our understanding of lncRNA biology offer hope for future breakthroughs in the field of pediatric neurology, leveraging lncRNAs as potential therapeutic targets and biomarkers.

Capturing evolving definitions of 12 select rare CNS tumors: a timely report from CBTRUS and NCI-CONNECT

PURPOSE

Incidence, prevalence, and survival are population-based statistics describing cancer burden. The National Cancer Institute's (NCI) Comprehensive Oncology Network Evaluating Rare CNS Tumors (NCI-CONNECT) specializes in tumor biology and outcomes for 12 rare CNS tumor types selected for their importance in adults, research interest, or potential for targeted treatment. The aim of this study was to update incidence, prevalence, and survival statistics for these tumors.

METHODS

The Central Brain Tumor Registry of the United States (CBTRUS) database, a combined dataset of Centers for Disease Control and Prevention's (CDC) National Program of Cancer Registries (NPCR) and NCI's Surveillance, Epidemiology and End Results (SEER) data, was used to calculate average annual age-adjusted incidence rates (AAAIR) per 100,000 population overall and by sex, race-ethnicity, and age for diagnosis years 2008-2019. Incidence time trends were calculated for diagnosis years 2004-2019. NPCR data were used to calculate relative survival rates. Point prevalence on December 31, 2019 was estimated using annual age-specific incidence and survival.

RESULTS

AAAIR was 1.47 per 100,000 for these tumors combined, with highest incidence in ependymomas (AAAIR = 0.41/100,000). Most tumor types were more common in males, adults (ages 40 + years) or children (ages < 15 years), and non-Hispanic White individuals. Ependymomas were the most prevalent tumor type (19,320 cases) followed by oligodendrogliomas (14,900 cases). Ependymomas had the highest five-year survival (90.6%) and primary CNS sarcomas the lowest (7.7%).

CONCLUSIONS

These data provide means to measure the impact of clinical care and evaluate new therapies and the evolving histopathology definitions in rare CNS tumor types.

Intracranial ependymoma in an adult patient with multiple primary malignancies

The incidence of multiple primary malignancies (MPM) is increasing, and therefore, it has become highly important for clinicians to consider the concept of MPM when treating oncology patients. In this case report, we follow the clinical course of a patient diagnosed with a new intracranial lesion, an ependymoma, on a background of MPM. We explore the barriers implicating the delay in her diagnosis, dissect the challenges in managing her disease and emphasise the importance of social determinants in optimising her care.

Potential Molecular Targets in the Treatment of Patients with CNS Tumors

The challenges in identifying effective therapies for CNS tumors continue to be daunting [...].

Magnetic Resonance Imaging Features of Zinc Finger Translocation Associated-RELA Fusion Ependymoma Compared to Its Wild-Type Counterpart

OBJECTIVE

To explore the predictive value of quantitative features extracted from conventional magnetic resonance imaging (MRI) in distinguishing Zinc Finger Translocation Associated (ZFTA)-RELA fusion-positive and wild-type ependymomas.

METHODS

Twenty-seven patients with pathologically confirmed ependymomas (17 patients with ZFTA-RELA fusions and 10 ZFTA-RELA fusion-negative patients) who underwent conventional MRI were enrolled in this retrospective study. Two experienced neuroradiologists who were blinded to the histopathological subtypes independently extracted imaging features using Visually Accessible Rembrandt Images annotations. The consistency between the readers was evaluated with the Kappa test. The imaging features with significant differences between the 2 groups were obtained using the least absolute shrinkage and selection operator regression model. Logistic regression analysis and receiver operating characteristic analysis were performed to analyze the diagnostic performance of the imaging features in predicting the ZFTA-RELA fusion status in ependymoma.

RESULTS

There was a good interevaluator agreement on the imaging features (kappa value range 0.601-1.000). Enhancement quality, thickness of the enhancing margin, and edema crossing the midline have high predictive performance in identifying ZFTA-RELA fusion-positive and ZFTA-RELA fusion-negative ependymomas (C-index = 0.862 and area under the curve= 0.8618).

CONCLUSIONS

Quantitative features extracted from preoperative conventional MRI by Visually Accessible Rembrandt Images provide high discriminatory accuracy in predicting the ZFTA-RELA fusion status of ependymoma.

[Pediatric posterior fossa tumors]

CLINICAL ISSUE

Tumors of the posterior fossa account for about 50-55% of brain tumors in childhood.

DIAGNOSTIC WORKUP

The most frequent tumor entities are medulloblastomas, pilocytic astrocytomas, ependymomas, diffuse midline gliomas and atypical teratoid-rhabdoid tumors. Neuroradiological differential diagnosis with magnetic resonance imaging (MRI) is of considerable importance for preoperative planning as well as planning of follow-up therapy.

PERFORMANCE

Most important findings for differential diagnosis of pediatric posterior fossa tumors are tumor location, patient age and the intratumoral apparent diffusion assessed by diffusion-weighted imaging.

ACHIEVEMENTS

Advanced MR techniques like MRI perfusion and MR spectroscopy can be helpful both in the initial differential diagnosis and in tumor surveillance, but exceptional characteristics of certain tumor entities should be kept in mind.

PRACTICAL RECOMMENDATIONS

Standard clinical MRI sequences including diffusion-weighted imaging are the main diagnostic tool in evaluating posterior fossa tumors in children. Advanced imaging methods can be helpful, but should never be interpreted separately from conventional MRI sequences.

Surgical Treatment of a Supratentorial Extraventricular Ependymoma: A Case Report

Supratentorial extraventricular ependymomas (STEE) are very rare primary tumors of the central nervous system (CNS). A 19-year-old man complained of headache, hemiparesis and seizures and was admitted to our hospital. Magnetic resonance imaging (MRI) revealed a right frontal intra-axial lesion. The patient underwent surgical treatment, and the tumor was resected successfully. A diagnosis of World Health Organization (WHO) grade 3 STEE was based on microscopic examination and immunohistochemical analysis. The patient was discharged without a neurological deficit.

Clinical Characteristics, Management, and Outcomes of Intramedullary Spinal Cord Ependymomas in Adults: A Systematic Review

BACKGROUND

Intramedullary spinal cord ependymomas (IMSCEs) are rare tumors that mostly occur in adults. Management strategies and related outcomes are heterogeneously reported across the literature, demanding a comprehensive analysis to standardize guidelines. We performed a systematic review of the literature on IMSCEs.

METHODS

A literature search was conducted using 6 databases from inception up to July 28, 2022. Studies with data on clinical characteristics, management strategies, and related outcomes in adult patients with histopathologically confirmed IMSCEs were pooled and analyzed.

RESULTS

The analysis included 69 studies comprising 457 patients (52.7% males). Mean age was 42.4 ± 7.4 years. Sensory deficit (58.0%) was the most prevalent symptom, followed by radicular pain (50.5%). Tumors mostly involved the cervical (64.4%) or thoracic (18.8%) spinal cord and were mostly World Health Organization grade II (80.5%) and classic subtype (72.4%). Gross total resection was performed in most cases (83.4%), with adjuvant radiotherapy delivered in 10.5% of cases. Progression-free survival ≥2 years was reported in 61.1% of cases, and tumor recurrence or progression was reported in only 7.0% of the patients. At last follow-up, 97.4% of patients were alive.

CONCLUSIONS

IMSCEs are uncommon tumors that frequently manifest with debilitating symptoms that require surgical treatment. When feasible, gross total resection may be pursued to improve the patient's functional status and prevent tumor progression, with adjuvant radiotherapy required only in some more aggressive grade III lesions. Future studies should investigate different growth patterns and prognoses based on different IMSCE subtypes.

Primary spinal anaplastic ependymoma: A single-institute retrospective cohort and systematic review

Objective

Primary spinal anaplastic ependymoma (PSAE) is an extremely rare disease. We aim to report the largest PSAE cohort, evaluate the treatments, and investigate the prognostic factors for progression-free survival (PFS).

Methods

Clinical data collected from the authors' institute and literature articles were pooled and described. Survival analysis and multivariable Cox regression analysis were performed to evaluate therapies and investigate prognostic factors for PFS.

Results

Our cohort included 22 females and 16 males, with a median age of 33 years. PSAE developed mostly on cervical and cervicothoracic levels. The median length measured 3 segments. Half of PSAE were intramedullary. Pain was the most common symptom. The median duration of symptoms was 6 months. Neurological statuses were improved in 76% following treatments, whereas clinical tumor progression occurred in 41.7%. The estimated median progression-free survival was 132 months, and the estimated median survival was 192 months. The median Ki-67 index was 15%. Patients aged less than or equal to 25 experienced worse neurological statuses and more repeated progression. Age less than or equal to 25 (HR 10.312, 95%CI 1.535-69.260, p=0.016), gross total resection (HR 0.116, 95%CI 0.020-0.688, p=0.018), and radiotherapy (HR 0.084, 95%CI 0.009-0.804, p=0.032) are three prognostic factors for tumor progression.

Conclusion

Tumor progression remains a big concern in the clinical course of PSAE. Being aged above 25, undergoing GTR, and accepting adjuvant radiotherapy put patients at lower risk for tumor progression. Younger patients might have worse neurological statuses compared with those aged over 25.

Novel nomograms predicting overall and cancer-specific survival of malignant ependymoma patients: a population-based study

BACKGROUND

Malignant ependymomas are rare cancerous tumors that are associated with increased morbidity and mortality in the affected patients. Lately, there has been a lot of controversy about the correct way to manage and predict the survival outcome of these patients. We aim in this retrospective cohort study to develop novel nomograms that can better predict the overall survival (OS) and cancer-specific survival (CSS) of these patients.

METHODS

This is a retrospective cohort study that was conducted through the Surveillance, Epidemiology, and End Results databases (SEER) between 1998 and 2016. Patients were excluded if they had an unknown diagnosis, unknown cause of death or those with survival duration less than a month. We used penalized regression models with the highest time-dependent area under the ROC curve (AUC) and most stable calibrations to construct the nomograms. By searching the SEER database and applying the eligibility criteria, we identified 3391 patients for the final analysis.

RESULTS

Nine penalized regression models were developed of which two models including adaptive elastic-net was selected for both OS and CSS. The model incorporated age, sex, year of diagnosis, site, race, radiation, chemotherapy, surgery, and type for the construction of nomograms. We aimed in this population-based cohort study to develop novel prediction tools that can help physicians estimate the survival of malignant ependymoma patients and provide better care.

CONCLUSIONS

Our nomograms appear to have high accuracy and applicability, which we hope that can predict the survival and improve the treatment and prognosis of these patients.

PARP inhibition utilized in combination therapy with Olaparib-Temozolomide to achieve disease stabilization in a rare case of BRCA1-mutant, metastatic myxopapillary ependymoma

Myxopapillary ependymoma (MPE) is a primary tumor of the central nervous system (CNS), characteristically an indolent malignancy involving the spinal conus medullaris, Filum terminale or cauda equina. We present a rare case of MPE, recurrent in the pelvic soft tissue with eventual pleural and intra-pulmonary metastasis. Refractory to repeated gross resection, adjuvant radiotherapy, platinum-based chemotherapy and temozolomide exploitation of mutant somatic BRCA1 status with the addition of a poly (ADP-ribose); polymerase inhibitor (PARPi) in a novel combination regimen with olaparib-temozolomide (OT) has achieved stable radiological disease after 10 cycles.

Ependymomas in Children and Adults

Ependymomas account for approximately 5% of all CNS tumors in adults and around 10% in the pediatric population. Contrary to traditional theories supporting that ependymomas arise from ependymal cells, recent studies propose radial glial cells as the cells of origin. In adults, half of the ependymomas arise in the spinal cord, whereas in the pediatric population, almost 90% of ependymomas are located intracranially. Most of the ependymomas are usually low-grade tumors except anaplastic variants and some cases of RELA-fusion-positive ependymomas, a molecular variant consisting the most recent addition to the 2016 World Health Organization (WHO) classification. Of note, the recently described molecular classification of ependymomas into nine distinct subgroups appears to be of greater clinical utility and prognostic value compared to the traditional histopathological classification, and parts of it are expected to be adopted by the WHO in the near future. Clinical manifestations depend on the location of the tumor with infratentorial ependymomas presenting with acute hydrocephalus. Gross total resection should be the goal of treatment. The prognostic factors of patients with ependymomas include age, grade, and location of the tumor, with children with intracranial, anaplastic ependymomas having the worst prognosis. In general, the 5-year overall survival of patients with ependymomas is around 60-70%.

Automated Classification of Intramedullary Spinal Cord Tumors and Inflammatory Demyelinating Lesions Using Deep Learning

Accurate differentiation of intramedullary spinal cord tumors and inflammatory demyelinating lesions and their subtypes are warranted because of their overlapping characteristics at MRI but with different treatments and prognosis. The authors aimed to develop a pipeline for spinal cord lesion segmentation and classification using two-dimensional MultiResUNet and DenseNet121 networks based on T2-weighted images. A retrospective cohort of 490 patients (118 patients with astrocytoma, 130 with ependymoma, 101 with multiple sclerosis [MS], and 141 with neuromyelitis optica spectrum disorders [NMOSD]) was used for model development, and a prospective cohort of 157 patients (34 patients with astrocytoma, 45 with ependymoma, 33 with MS, and 45 with NMOSD) was used for model testing. In the test cohort, the model achieved Dice scores of 0.77, 0.80, 0.50, and 0.58 for segmentation of astrocytoma, ependymoma, MS, and NMOSD, respectively, against manual labeling. Accuracies of 96% (area under the receiver operating characteristic curve [AUC], 0.99), 82% (AUC, 0.90), and 79% (AUC, 0.85) were achieved for the classifications of tumor versus demyelinating lesion, astrocytoma versus ependymoma, and MS versus NMOSD, respectively. In a subset of radiologically difficult cases, the classifier showed an accuracy of 79%-95% (AUC, 0.78-0.97). The established deep learning pipeline for segmentation and classification of spinal cord lesions can support an accurate radiologic diagnosis. Supplemental material is available for this article. © RSNA, 2022 Keywords: Spinal Cord MRI, Astrocytoma, Ependymoma, Multiple Sclerosis, Neuromyelitis Optica Spectrum Disorder, Deep Learning.

Characterization and Treatment of Spinal Tumors

The prevalence of spinal tumors is rare in comparison to brain tumors which encompass most central nervous system tumors. Tumors of the spine can be divided into primary and metastatic tumors with the latter being the most common presentation. Primary tumors are subdivided based on their location on the spinal column and in the spinal cord into intramedullary, intradural extramedullary, and primary bone tumors. Back pain is a common presentation in spine cancer patients; however, other radicular pain may be present. Magnetic resonance imaging (MRI) is the imaging modality of choice for intradural extramedullary and intramedullary tumors. Plain radiographs are used in the initial diagnosis of primary bone tumors while Computed tomography (CT) and MRI may often be necessary for further characterization. Complete surgical resection is the treatment of choice for spinal tumors and may be curative for well circumscribed lesions. However, intralesional resection along with adjuvant radiation and chemotherapy can be indicated for patients that would experience increased morbidity from damage to nearby neurological structures caused by resection with wide margins. Even with the current treatment options, the prognosis for aggressive spinal cancer remains poor. Advances in novel treatments including molecular targeting, immunotherapy and stem cell therapy provide the potential for greater control of malignant and metastatic tumors of the spine.

Resection and radiotherapy for intracranial ependymoma: a multiinstitutional 50-year experience

OBJECTIVE

Maximal safe resection is the standard-of-care treatment for adults with intracranial ependymoma. The value of adjuvant radiotherapy remains unclear as these tumors are rare and current data are limited to a few retrospective cohort studies. In this study, the authors assembled a cohort of patients across multiple international institutions to assess the utility of adjuvant radiotherapy in this patient population.

METHODS

Adults with intracranial ependymoma managed surgically at the University Health Network in Toronto, Canada, the University of Oklahoma Health Sciences Center in Oklahoma City, Oklahoma, and The Ottawa Hospital in Ottawa, Canada, were included in this study. The primary end points were progression-free survival (PFS) and overall survival (OS). Clinicopathological variables were assessed in univariate and multivariate Cox proportional hazard models for prognostic significance of PFS and OS.

RESULTS

A total of 122 patients diagnosed between 1968 and 2019 were identified for inclusion. The majority of patients had grade II ependymomas on histopathology (78%) that were infratentorially located (71%), underwent gross-total (GTR) or near-total resection (NTR; 55%), and were treated with adjuvant radiotherapy (67%). A volumetric analysis of the extent of resection in 49 patients with available tumor volume data supported the accuracy of the categorical GTR, NTR, and subtotal resection (STR) groups utilized. Independent statistically significant predictors of poorer PFS in the multivariate analysis included STR or biopsy (vs GTR/NTR; HR 5.4, 95% confidence interval [CI] 2.4-11.0, p < 0.0001) and not receiving adjuvant radiotherapy; cranial (HR 0.5, 95% CI 0.2-1.1) and craniospinal (HR 0.2, 95% CI 0.04-0.5) adjuvant radiotherapy regimens improved PFS (p = 0.0147). Predictors of poorer OS in the multivariate analysis were grade III histopathology (vs grade II: HR 5.7, 95% CI 1.6-20.2, p = 0.0064) and undergoing a biopsy/STR (vs GTR/NTR: HR 9.8, 95% CI 3.2-30.1, p = 0.0001).

CONCLUSIONS

The results of this 50-year experience in treating adult intracranial ependymomas confirm an important role for maximal safe resection (ideally GTR or NTR) and demonstrate that adjuvant radiotherapy improves PFS. This work will guide future studies as testing for molecular ependymoma alterations become incorporated into routine clinical practice.

Perioperative outcomes and survival after surgery for intramedullary spinal cord tumors: a single-institution series of 302 patients

OBJECTIVE

Intramedullary spinal cord tumors (IMSCTs) are rare neoplasms whose treatment is often technically challenging. Given the low volume seen at most centers, perioperative outcomes have been reported infrequently. Here, the authors present the largest single-institution series of IMSCTs, focusing on the clinical presentation, histological makeup, perioperative outcomes, and long-term survival of surgically treated patients.

METHODS

A cohort of patients operated on for primary IMSCTs at a comprehensive cancer center between June 2002 and May 2020 was retrospectively identified. Data on patient demographics, tumor histology, neuraxial location, baseline neurological status, functional deficits, and operative characteristics were collected. Perioperative outcomes of interest included length of stay, postoperative complications, readmission, reoperation, and discharge disposition. Data were compared across tumor histologies using the Kruskal-Wallis H test, chi-square test, and Fisher exact test. Pairwise comparisons were conducted using Tukey's honest significant difference test, chi-square test, and Fisher exact test. Long-term survival was assessed across tumor categories and histological subtype using the log-rank test.

RESULTS

Three hundred two patients were included in the study (mean age 34.9 ± 19 years, 77% white, 57% male). The most common tumors were ependymomas (47%), astrocytomas (31%), and hemangioblastomas (11%). Ependymomas and hemangioblastomas disproportionately localized to the cervical cord (54% and 59%, respectively), whereas astrocytomas were distributed almost equally between the cervical cord (36%) and thoracic cord (38%). Clinical presentation, extent of functional dependence, and postoperative 30-day outcomes were largely independent of underlying tumor pathology, although tumors of the thoracic cord had worse American Spinal Injury Association (ASIA) grades than cervical tumors. Rates of gross-total resection were lower for astrocytomas than for ependymomas (54% vs 84%, p < 0.01) and hemangioblastomas (54% vs 100%, p < 0.01). Additionally, 30-day readmission rates were significantly higher for astrocytomas than ependymomas (14% vs 6%, p = 0.02). Overall survival was significantly affected by the underlying pathology, with astrocytomas having poorer associated prognoses (40% at 15 years) than ependymomas (81%) and hemangioblastomas (66%; p < 0.01) and patients with high-grade ependymomas and astrocytomas having poorer long-term survival than those with low-grade lesions (p < 0.01).

CONCLUSIONS

The neuraxial location of IMSCTs, extent of resection, and postoperative survival differed significantly across tumor pathologies. However, perioperative outcomes did not vary significantly across tumor cohorts, suggesting that operative details, rather than pathology, may have a stronger influence on the short-term clinical course, whereas pathology appears to have a stronger impact on long-term survival.

Gliomas: Genetic alterations, mechanisms of metastasis, recurrence, drug resistance, and recent trends in molecular therapeutic options

Glioma is the most common intracranial tumor with poor treatment outcomes and has high morbidity and mortality. Various studies on genomic analyses of glioma found a variety of deregulated genes with somatic mutations including TERT, TP53, IDH1, ATRX, TTN, etc. The genetic alterations in the key genes have been demonstrated to play a crucial role in gliomagenesis by modulating important signaling pathways that alter the fundamental intracellular functions such as DNA damage and repair, cell proliferation, metabolism, growth, wound healing, motility, etc. The SPRK1, MMP2, MMP9, AKT, mTOR, etc., genes, and noncoding RNAs (miRNAs, lncRNAs, circRNAs, etc) were shown mostly to be implicated in the metastases of glioma. Despite advances in the current treatment strategies, a low-grade glioma is a uniformly fatal disease with overall median survival of ∼5-7 years while the patients bearing high-grade tumors display poorer median survival of ∼9-10 months mainly due to aggressive metastasis and therapeutic resistance. This review discusses the spectrum of deregulated genes, molecular and cellular mechanisms of metastasis, recurrence, and its management, the plausible causes for the development of therapy resistance, current treatment options, and the recent trends in malignant gliomas. Understanding the pathogenic mechanisms and advances in molecular genetics would aid in the novel diagnosis, prognosis, and translation of pathogenesis-based treatment opportunities which could pave the way for precision medicine in glioma.

Single cell transcriptomics reveals unique metabolic profiles of ependymoma subgroups

OBJECTIVE

Ependymomas are biologically diverse tumors with five major genomic subgroups. However, intratumor heterogeneity continues to be poorly understood. The present study characterized the metabolic landscapes of ependymoma subgroups at the single-cell level.

METHODS

Expression profiles from 11,200 ependymoma single cells derived from the five major subgroups and 7,200 ependymoma-derived non-neoplastic cells were computationally analyzed using a robust workflow to elucidate relative differences in metabolic pathway activities.

RESULTS

Dimensionality reduction using metabolic expression profiles exhibited clustering corresponding to each tumor subgroup, but non-neoplastic cells exhibited no discernable differences between subgroups. From the 80 metabolic pathways examined, over 75 pathways had significantly different activity scores between ependymoma subgroups. Further analysis of metabolic heterogeneity suggests that mitochondrial oxidative phosphorylation accounts for considerable metabolic variation within tumor subgroups and non-neoplastic cells of the same cell type. Drug metabolism pathways, specifically those involving cytochromes P450, were also found to be major contributors to heterogeneity.

CONCLUSIONS

Ependymoma subgroups display distinct metabolic differences as evaluated through gene expression profiles with certain pathways contributing greatly to intra-subgroup variation. These results may account for variation in tumor metabolism, treatment response, and potential targeting approaches that disrupt metabolic signalling.

Extra-Neural Metastases From Primary Intracranial Ependymomas: A Systematic Review

Background

Primary intracranial ependymomas (IE) are rare brain tumors rarely metastasizing outside the central nervous system. We systematically reviewed the literature on extra-neural metastases from primary IEs.

Methods

PubMed, Scopus, Web-of-Science, and Cochrane were searched following the PRISMA guidelines to include studies of extra-neural metastases from primary IEs. Clinical features, management strategies, and survival were analyzed.

Results

We collected 48 patients from 43 studies. Median age was 13 years (range, 2-65). Primary IEs were frequently located in the parietal (22.9%) and frontal (16.7%) lobes, and mostly treated with resection (95.8%) and/or radiotherapy (62.5%). Most IEs were of grade-III (79.1%), and few of grade-I (6.3%) or grade-II (14.6%). 45 patients experienced intracranial recurrences, mostly treated with resection (86.7%), radiotherapy (60%), and/or chemotherapy (24.4%). Median time-interval from primary IEs was 28 months (range, 0-140). Most extra-neural metastases were diagnosed at imaging (37.5%) or autopsy (35.4%). Extra-neural metastases were multifocal in 38 patients (79.1%), mostly involving cervical or hilar lymph-nodes (66.7%), lung/pleura (47.9%), and/or scalp (29.1%). Surgical resection (31.3%), chemotherapy (31.3%) and locoregional radiotherapy (18.8%) were the most common treatments for extra-neural metastases, but 28 (58.3%) patients were not treated. At last follow-up, 37 patients died with median overall-survivals from primary IEs of 36 months (range, 1-239), and from extra-neural metastases of 3 months (range, 0.1-36). Overall-survival was significantly longer in patients with grade-I and II IEs (P=0.040).

Conclusion

Extra-neural metastases from primary IEs are rare, but mostly occur at later disease stages. Multidisciplinary management strategies should be intended mostly for palliation.

Rare CNS tumors in adults: a population-based study of ependymomas, pilocytic astrocytomas, medulloblastomas and intracranial germ cell tumors

Background

Ependymomas, pilocytic astrocytomas, medulloblastomas, and intracranial germ cell tumors occur relative frequently in children, but are rare central nervous system (CNS) tumors in adults. In this population-based survey, we established incidence, treatment, and survival patterns for these tumors diagnosed in adult patients (≥18 years) over a 30-year period (1989–2018).

Methods

Data on 1384 ependymomas, 454 pilocytic astrocytomas, 205 medulloblastomas, and 112 intracranial germ cell tumors were obtained from the Netherlands Cancer Registry (NCR) on the basis of a histopathological diagnosis. For each tumor type, age-standardized incidence rates and estimated annual percentage change were calculated. Trends in incidence and main treatment modalities were reported per 5-year periods. Overall survival was calculated using the Kaplan–Meier method, and relative survival rates were estimated using the Pohar-Perme estimator.

Results

Incidence and survival rates remained generally stable for pilocytic astrocytomas, medulloblastomas, and germ cell tumors. Increasing incidence was observed for spinal ependymomas, mostly for myxopapillary ependymomas, and survival improved over time for grade II ependymomas (P < .01). Treatment patterns varied over time with shifting roles for surgery in ependymomas and for chemotherapy and radiation in medulloblastomas and germinomas.

Conclusions

The study provides baseline information for highly needed national and international standard treatment protocols, and thus for further improving patient outcomes in these rare CNS tumors.

Ependymoma: Evaluation and Management Updates

PURPOSE OF REVIEW

To review state of art and relevant advances in the molecular genetics and management of ependymomas of children and adults.

RECENT FINDINGS

Ependymomas may occur either in the brain or in the spinal cord. Compared with intracranial ependymomas, spinal ependymomas are less frequent and exhibit a better prognosis. The new WHO classification of CNS tumors of 2021 has subdivided ependymomas into different histomolecular subgroups with different outcome. The majority of studies have shown a major impact of extent of resection; thus, a complete resection must be performed, whenever possible, at first surgery or at reoperation. Conformal radiotherapy is recommended for grade 3 or incompletely resected grade II tumors. Proton therapy is increasingly employed especially in children to reduce the risk of neurocognitive and endocrine sequelae. Craniospinal irradiation is reserved for metastatic disease. Chemotherapy is not useful as primary treatment and is commonly employed as salvage treatment for patients failing surgery and radiotherapy. Standard treatments are still the mainstay of treatment: the discovery of new druggable pathways will hopefully increase the therapeutic armamentarium in the near future.

Descriptive epidemiology of ependymal tumors in Gironde, France: results from the Gironde Registry for the 2000-2018 period

BACKGROUND

The Gironde Central Nervous System (CNS) Tumor Registry, in collaboration with the French National Cancer Institute, is the largest population-based registry focused exclusively on primary CNS tumors in France and represents a population of 1.62 million. This report focuses on ependymal tumors to refine current knowledge and provide up-to-date data on the epidemiology of these rare tumors.

MATERIAL AND METHODS

All of the ependymal tumors were extracted from the Gironde CNS Tumor Registry for the years 2000 to 2018. Demographic and clinical characteristics, incidence rates and time trends as well as survival outcomes were analyzed.

RESULTS

One hundred and forty-four ependymal tumors were retrieved, which represented 2.3% of all the CNS tumors recorded in the same period. Histological subtype was significantly dependent on age and topography in the CNS. The median age at diagnosis was 46 years old. The annual incidence rates varied between 0.15/100,000 (2004) and 0.96/100,000 (2016), with a significant increase over the study period by 4.67% per year. Five-year and 10-year OS rates were 87% and 80%, respectively.

CONCLUSION

An increase in the incidence of ependymal tumors was observed over the past two decades. Further studies are needed to confirm this result and provide etiological clues.

Immunohistochemical Expression of p27Kip1, p57Kip2, Cyclin D1, Nestin, and Ki-67 in Ependymoma

p27 and p57 are tumor suppressors that are dysregulated in many cancers. We investigated the immunohistochemical expression of p27 and p57 in ependymoma, with a secondary emphasis on cyclin D1, nestin, and Ki-67. Sixty-five patients diagnosed with ependymoma were included. Clinical and tumoral data were retrieved, and the expression of p27, p57, cyclin D1, nestin, and Ki-67 was measured. Pearson’s χ2 test was used to measure associations and the Kaplan–Meier method was used for survival analysis. p27 underexpression was significantly associated with pseudopalisading necrosis in tumors with foci of necrosis (p = 0.004). Cyclin D1 overexpression was associated with intracranial (p = 0.044), recurrent (p = 0.022) and grade 3 tumors (p = 0.016); nestin overexpression was associated with supratentorial (p = 0.025), mitotically active (p < 0.001), and grade 3 tumors (p = 0.004); Ki-67 overexpression was associated with supratentorial (p = 0.044) and grade 3 tumors (p < 0.001) and the 3 main features of anaplasia. None of the markers were intercorrelated or predictive of overall survival. In conclusion, p27 underexpression in tumors with foci of necrosis signals a pseudopalisading pattern. Cyclin D1, nestin, and Ki-67 are useful markers in ependymoma, but evidence-based cutoff values are required to standardize this interpretation.