Adult cerebellar glioblastoma: understanding survival and prognostic factors using a population-based database from 1973 to 2009

Cerebellar glioblastoma in adults: a comparative single-center matched pair analysis and systematic review of the literature

PURPOSE

The rarity of cerebellar glioblastoma presents a significant challenge in clinical practice due to the lack of extensive prognostic data on long-term survival rates, rendering it an underrepresented entity compared to its supratentorial counterpart. This study aims to analyze potential differences in survival outcome between patients with cerebellar and supratentorial glioblastomas.

METHODS

From 2009 to 2020, 8 patients underwent surgical treatment for cerebellar glioblastoma at the authors' institution. These patients were individually matched with a cohort of 205 consecutive patients from our institutional database with supratentorial glioblastoma, taking into account key prognostic parameters. Progression-free survival (PFS) and overall survival (OS) rates were compared. Additionally, we performed a systematic literature review to compile further survival data on cerebellar glioblastoma patients.

RESULTS

The median OS for cerebellar glioblastoma patients was 18 months (95% CI 11-25). The balanced matched-pair analysis showed no significant difference in survival when compared to patients with supratentorial glioblastoma, exhibiting a median OS of 23 months (95% CI 0-62) (p = 0.63). Respective values for PFS were 8 months (95% CI 4-12) for cerebellar and 7 months (95% CI 0-16) for supratentorial glioblastoma (p = 0.2). The systematic review revealed that median OS for cerebellar glioblastoma in current literature ranges from 7 to 21 months.

CONCLUSIONS

The present findings indicate that patients with supra- and infratentorial glioblastoma do not significantly differ in regard to survival outcome parameters. This similarity in prognosis might encourage clinicians to consider surgical interventions for both supra- and infratentorial glioblastoma in a similar manner.

Racial and social-economic inequalities in systemic chemotherapy use among adult glioblastoma patients following surgery and radiotherapy

Not all patients with glioblastoma multiforme (GBM) eligible for systemic chemotherapy after upfront surgery and radiotherapy finally receive it. The information on patients with GBM was retrieved from the surveillance, epidemiology, and end results database. Patients who underwent upfront surgery or biopsy and external beam radiotherapy between 2010 and 2019 were eligible for systemic chemotherapy. The available patient and tumor characteristics were assessed using multivariable logistic regression and chi-squared test. Out of the 16,682 patients eligible, 92.1% underwent systemic chemotherapy. The characteristics linked to the lowest systemic chemotherapy utilization included tumors of the brain stem/cerebellum (P = 0.01), former years of diagnosis (P = 0.001), ≥ 80 years of age (P < 0.001), Hispanic, Non-Hispanic Asian, Pacific Islander, or Black race (P < 0.001), non-partnered status (P < 0.001), and low median household income (P = 0.006). Primary tumor site, year of diagnosis, age, race, partnered status, and median household income correlated with the omission of systemic chemotherapy in GBM in adult patients.

Clinical features and treatment of apoplectic intratumoral hemorrhage of glioma

OBJECTIVE

The primary objective of this study was to explore the clinical characteristics of apoplectic intratumoral hemorrhage in gliomas and offer insights for improving the diagnosis and treatment of this disease.

METHODS

We analyzed the clinical data of 35 patients with glioma and hemorrhage. There were eight cases of multiple cerebral lobe involvement, and 22 cases involved a single lobe. Twenty-one patients had a preoperative Glasgow Coma Scale (GCS) score of ≥ 9 and had a craniotomy with tumor resection and hematoma evacuation after undergoing preoperative preparation. A total of 14 patients with GCS < 9, including one with thalamic hemorrhage breaking into the ventricles and acute obstructive hydrocephalus, underwent craniotomy for tumor resection after external ventricular drainage (EVD). One patient had combined thrombocytopenia, which was surgically treated after platelet levels were normalized through transfusion. The remaining 12 patients received immediate intervention in the form of craniotomy hematoma evacuation and tumor resection.

RESULTS

We performed subtotal resection on three tumors of thalamic origin and two tumors of corpus callosum origin, but we were able to successfully resect all the tumors in other locations that were gross total resection Pathology results showed that 71.43% of cases accounted for WHO-grade 4 tumors. Among the 21 patients with a GCS score of ≥ 9, two died perioperatively. Fourteen patients had a GCS score < 9, of which eight patients died perioperatively.

CONCLUSIONS

Patients with a preoperative GCS score ≥ 9 who underwent subemergency surgery and received aggressive treatment showed a reasonable prognosis. We found their long-term outcomes to be correlated with the pathology findings. On the other hand, patients with a preoperative GCS score < 9 required emergency treatment and had a high perioperative mortality rate.

Investigating distinct clinical features and constructing a nomogram model for survival probability in adults with cerebellar high-grade gliomas

BACKGROUND

The clinical features of cerebellar high-grade gliomas (cHGGs) in adults have not been thoroughly explored. This large-scale, population-based study aimed to comprehensively outline these traits and construct a predictive model.

METHODS

Patient records diagnosed with gliomas were collected from various cohorts and analyzed to compare the features of cHGGs and supratentorial HGGs (sHGGs). Cox regression analyses were employed to identify prognostic factors for overall survival and to develop a nomogram for predicting survival probabilities in patients with cHGGs. Multiple machine learning methods were applied to evaluate the efficacy of the predictive model.

RESULTS

There were significant differences in prognosis, with SEER-cHGGs showing a median survival of 7.5 months and sHGGs 14.9 months (p < 0.001). Multivariate Cox regression analyses revealed that race, WHO grade, surgical procedures, radiotherapy, and chemotherapy were independent prognostic factors for cHGGs. Based on these factors, a nomogram was developed to predict 1-, 3-, and 5-year survival probabilities, with AUC of 0.860, 0.837, and 0.810, respectively. The model's accuracy was validated by machine learning approaches, demonstrating consistent predictive effectiveness.

CONCLUSIONS

Adult cHGGs are distinguished by distinctive clinical features different from those of sHGGs and are associated with an inferior prognosis. Based on these risk factors affecting cHGGs prognosis, the nomogram prediction model serves as a crucial tool for clinical decision-making in patient care.

A Synopsis of Biomarkers in Glioblastoma: Past and Present

Accounting for 48% of malignant brain tumors in adults, glioblastoma has been of great interest in the last decades, especially in the biomolecular and neurosurgical fields, due to its incurable nature and notable neurological morbidity. The major advancements in neurosurgical technologies have positively influenced the extent of safe tumoral resection, while the latest progress in the biomolecular field of GBM has uncovered new potential therapeutical targets. Although GBM currently has no curative therapy, recent progress has been made in the management of this disease, both from surgical and molecular perspectives. The main current therapeutic approach is multimodal and consists of neurosurgical intervention, radiotherapy, and chemotherapy, mostly with temozolomide. Although most patients will develop treatment resistance and tumor recurrence after surgical removal, biomolecular advancements regarding GBM have contributed to a better understanding of this pathology and its therapeutic management. Over the past few decades, specific biomarkers have been discovered that have helped predict prognosis and treatment responses and contributed to improvements in survival rates.

Isocitrate Dehydrogenase (IDH)-Mutant High-Grade Glioma in the Cerebellum: A Case Report

High-grade glial cancers typically arise in the cerebral hemisphere and rarely in the cerebellum. Our objective was to highlight the diagnostic features of isocitrate dehydrogenase (IDH)-mutant high-grade gliomas in the cerebellum. We present a case of an elderly patient admitted with giddiness who was diagnosed with IDH-mutant high-grade glioma in the cerebellum, presenting as multiple lesions. We evaluated an open biopsy specimen to arrive at a diagnosis and used molecular studies to confirm the diagnosis and further categorize the specimens. Histopathology and immunohistochemistry confirmed the diagnosis of IDH-mutant high-grade glioma in the cerebellum.

A common tumour in a rare location: a single centre case series of cerebellar glioblastoma

Although glioblastoma is the commonest primary brain tumour in adults, its location in the cerebellum is extremely rare. We present thirteen cases (3 female, 10 male; median age at presentation 56 [age range 21-77]) of surgically managed, histologically confirmed, primary cerebellar glioblastoma (cGB) over a 17 year period (2005-2022). Pre-operative radiological diagnosis was challenging given cGB rarity, although MRI demonstrated ring enhancement in all cases. Surgical management included posterior fossa craniectomy and debulking in 11 cases and burr hole biopsy in two. CSF diversion was necessary in four cases. No evidence of IDH or ATRX gene mutations was found when tested. Survival ranged from 1 to 22 months after diagnosis (mean 10.9 months). We also seek to understand why glioblastoma is rare in this location and discuss potential reasons for this. We hypothesise that increasing anatomical distance from germinal regions and decreased local endogenous neural stem cell activity (which has been associated with glioblastoma) may explain why glioblastoma is rare in the cerebellum. We hereby seek to add to the limited literature on cGB as this is the largest UK cGB series to date.

Factors associated with longer survival among older medicare patients after diagnosis of supratentorial primary brain malignancies: a retrospective cohort study

OBJECTIVES

Despite recent advances, the prognosis for primary malignant brain tumors (PMBTs) remains poor. Some commonly prescribed medications may exhibit anti-tumor properties in various cancers, and neurodegenerative diseases may activate pathways that counteract gliomagenesis. Our study is focused on determining if there is a correlation between the use of metformin, beta-blockers, angiotensin converting enzyme inhibitors (ACEIs), and angiotensin receptor blockers (ARBs), or the presence of Parkinson's disease (PD), and the survival rates following a diagnosis of a PMBT.

METHODS

This analysis of the 100% Texas Medicare Database identified patients aged 66+ years diagnosed with a supratentorial PMBT from 2014-2017. Cox proportional hazards regression was employed to analyze survival following diagnosis and associations of survival with surgical intervention, radiation, PD diagnosis, and prescription of metformin, beta-blockers, ACEIs, or ARBs.

RESULTS

There were 1,943 patients who met study criteria, and the median age was 74 years. When medication utilization was stratified by none, pre-diagnosis only, post-diagnosis only, or both pre- and post-diagnosis (continuous), continuous utilization of metformin, beta-blockers, ACEIs, or ARBs was associated with prolonged survival compared to no utilization (hazard ratio [HR]:0.45, 95% CI:0.33-0.62; HR:0.71. 95% CI:0.59-0.86; HR:0.59, 95% CI:0.48-0.72; and HR:0.45, 95% CI:0.35-0.58 respectively). PD was also associated with longer survival (HR:0.59-0.63 across the four models).

DISCUSSION

Our study suggests that metformin, beta-blockers, ACEIs, ARBs, and comorbid PD are associated with a survival benefit among geriatric Medicare patients with supratentorial PMBTs.

Radiotherapy-induced glioblastoma: distinct differences in overall survival, tumor location, pMGMT methylation and primary tumor epidemiology in Hong Kong chinese patients

INTRODUCTION

Radiotherapy-induced glioblastomas (RIGB) are a well-known late and rare complication of brain irradiation. Yet the clinical, radiological and molecular characteristics of these tumors are not well characterized.

METHODS

This was a retrospective multicentre study that analysed adult patients with newly diagnosed glioblastoma over a 10-year period. Patients with RIGB were identified according to Cahan's criteria for radiation-induced tumors. A case-control analysis was performed to compare known prognostic factors for overall survival (OS) with an independent cohort of IDH-1 wildtype de novo glioblastomas treated with standard temozolomide chemoradiotherapy. Survival analysis was performed by Cox proportional hazards regression.

RESULTS

A total of 590 adult patients were diagnosed with glioblastoma. 19 patients (3%) had RIGB. The mean age of patients upon diagnosis was 48 years ± 15. The mean latency duration from radiotherapy to RIGB was 14 years ± 8. The mean total dose was 58Gy ± 10. One-third of patients (37%, 7/19) had nasopharyngeal cancer and a fifth (21%, 4/19) had primary intracranial germinoma. Compared to a cohort of 146 de novo glioblastoma patients, RIGB patients had a shorter median OS of 4.8 months versus 19.2 months (p-value: <.001). Over a third of RIGBs involved the cerebellum (37%, 7/19) and was higher than the control group (4%, 6/146; p-value: <.001). A fifth of RIGBs (21%, 3/19) were pMGMT methylated which was significantly fewer than the control group (49%, 71/146; p-value: .01). For RIGB patients (32%, 6/19) treated with re-irradiation, the one-year survival rate was 67% and only 8% for those without such treatment (p-value: .007).

CONCLUSION

The propensity for RIGBs to develop in the cerebellum and to be pMGMT unmethylated may contribute to their poorer prognosis. When possible re-irradiation may offer a survival benefit. Nasopharyngeal cancer and germinomas accounted for the majority of original malignancies reflecting their prevalence among Southern Chinese.

Advancing precision prognostication in neuro-oncology: Machine learning models for data-driven personalized survival predictions in IDH-wildtype glioblastoma

Background

Glioblastoma (GBM) remains associated with a dismal prognoses despite standard therapies. While population-level survival statistics are established, generating individualized prognosis remains challenging. We aim to develop machine learning (ML) models that generate personalized survival predictions for GBM patients to enhance prognostication.

Methods

Adult patients with histologically confirmed IDH-wildtype GBM from the National Cancer Database (NCDB) were analyzed. ML models were developed with TabPFN, TabNet, XGBoost, LightGBM, and Random Forest algorithms to predict mortality at 6, 12, 18, and 24 months postdiagnosis. SHapley Additive exPlanations (SHAP) were employed to enhance the interpretability of the models. Models were primarily evaluated using the area under the receiver operating characteristic (AUROC) values, and the top-performing models indicated by the highest AUROCs for each outcome were deployed in a web application that was created for individualized predictions.

Results

A total of 7537 patients were retrieved from the NCDB. Performance evaluation revealed the top-performing models for each outcome were built using the TabPFN algorithm. The TabPFN models yielded mean AUROCs of 0.836, 0.78, 0.732, and 0.724 in predicting 6, 12, 18, and 24 month mortality, respectively.

Conclusions

This study establishes ML models tailored to individual patients to enhance GBM prognostication. Future work should focus on external validation and dynamic updating as new data emerge.

Survival outcomes and prognostic factors of infratentorial glioblastoma in the elderly

INTRODUCTION

Infratentorial glioblastoma(itGBM) is a rare and rapidly progressive form of GBM with poor prognosis. However, no studies have adequately examined itGBM outcomes in elderly patients (>65 years). Here, we used a national database to fill this knowledge gap.

METHODS

SEER 18 registries were utilized to identify adult itGBM patients diagnosed between 2000-2016. itGBM cases were further divided into cerebellar and brainstem GBM as cGBM and bGBM, respectively. Kaplan-Meier analysis and Cox hazards proportional regression models were performed to assess factors associated with overall survival (OS).

RESULTS

Among 137 (33%) elderly patients from the study cohort (N = 420), median age was 74 years, 38% were female, and 85% were white. Median OS in elderly itGBM patients was shorter than younger adults (10 vs. 5-months, p < 0.001). Multivariate analysis by tumor location revealed that older age was associated with poor survival for cGBM, but not for bGBM. Gross-total resection (GTR) was associated with better outcomes for both cGBM and bGBM. Radiotherapy had survival benefits for cGBM; meanwhile, chemotherapy prolonged OS in bGBM. In the elderly, advanced age (80 + years) was associated with poor outcomes, while GTR, CT and RT were all associated with improved survival.

CONCLUSIONS

In our study, while elderly patients had worse survival compared to younger adults for both cGBM and bGBM, GTR improved OS in elderly itGBM, with CT and RT exhibiting a location-dependent survival benefit. Thus, elderly itGBM patients should undergo a combination of maximal resection and adjuvant treatment guided by infratentorial tumor location for maximal survival benefit.

Molecular Characterization of Adult Tumors Diagnosed as Cerebellar Glioblastomas Identifies Subgroups Associated With Prognosis

Adult tumors diagnosed as cerebellar glioblastoma (cGBM) are rare and their optimal classification remains to be determined. The aim of this study was to identify subgroups of cGBM based on targeted molecular analysis. cGBM diagnosed between 2003 and 2017 were identified from the French Brain Tumor Database and reviewed according to the WHO 2021 classification. The following molecular alterations were studied: IDH1/2 , H3F3A , FGFR1 , BRAF , TERT promoter mutations, EGFR amplification, MGMT promoter methylation, and alternative lengthening of telomere status. DNA methylation profile was assessed in a subset of cases. Eighty-three cGBM were included and could be classified into 6 mutually exclusive subgroups associated with median age at diagnosis (MA) and prognosis: TERT -mutant and/or EGFR -amplified tumors (n=22, 26.5%, MA=62 y, median overall survival [OS]=4 mo), H3K27M-mutant tumors (n=15, 18.1%, MA=48 y, median OS=8 mo), mitogen-activated protein kinases (MAPK) pathway-activated tumors ( FGFR1 , BRAF mutation, or occurring in neurofibromatosis type I patients, n=15, 18.1%, MA=48 y, median OS=57 mo), radiation-associated tumors (n=5, 6%, MA=47 y, median OS=5 mo), IDH-mutant tumors (n=1), and unclassified tumors (n=25, 30.1%, MA=63 y, median OS=17 mo). Most MAPK pathway-activated tumors corresponded to high-grade astrocytomas with piloid features based on DNA methylation profiling. In multivariate analysis, MAPK pathway-activating alterations, ATRX loss of expression, and alternative lengthening of telomere positivity were independently associated with a better outcome and TERT / EGFR alterations with a worse outcome. cGBM display an important intertumoral heterogeneity. Targeted molecular analysis enables to classify the majority of tumors diagnosed as cGBM into mutually exclusive and clinically relevant subgroups. The presence of MAPK pathway alterations is associated with a much better prognosis.

OLIG2 expression level could be used as an independent prognostic factor for patients with cerebellar Glioblastoma (cGBM)

OBJECTIVES

The incidence of cerebellar Glioblastoma Multiforme (cGBM) is rare. Database like TCGA have not distinguish cGBM from GBM, our knowledge on cGBM gene expression characteristics is limited. The expression status of Oligodendrocyte Lineage Transcription factor 2 (OLIG2) and its clinical significance in cGBM is still unclear.

METHODS

The clinical data and tissue specimens of 73 cGBM patients were retrospectively studied. The association between OLIG2 expression level and the demographic characteristics of cGBM patients was identified by the Chi-Square test. The survival curves were drawn by Kaplan-Meier analysis. The independent prognostic factors was calculated according to Cox regression analysis.

RESULTS

The OLIG2 high expression was observed in about 57.5% (42/73) of the cGBM patients. Patients with high OLIG2 expression levels had a higher alive ratio at the end of follow-up (alive ratio: 70.6% vs. 29.4%, p = 0.04). The median survival time was 21 months and 13 months for high and low expression of OLIG2 (p < 0 .05). Univariate analysis and Multivariate analysis indicated that EOR (HR = 3.89, 95% CI 1.23‒12.26, p = 0.02), low OLIG2 expression (HR = 5.26, 95% CI 1.13‒24.59, p = 0.04), and without adjuvant therapy (HR = 4.95, 95% CI 1.22‒20.00, p = 0.03) were independent risk factors for the OS of cGBM patients.

CONCLUSION

High expression level of OLIG2 could be used as an independent favorable prognosis indicator in cGBM patients and be recognized as a characteristic biomarker of cGBM.

Cerebellar High-Grade Glioma: A Translationally Oriented Review of the Literature

World Health Organization (WHO) grade 4 gliomas of the cerebellum are rare entities whose understanding trails that of their supratentorial counterparts. Like supratentorial high-grade gliomas (sHGG), cerebellar high-grade gliomas (cHGG) preferentially affect males and prognosis is bleak; however, they are more common in a younger population. While current therapy for cerebellar and supratentorial HGG is the same, recent molecular analyses have identified features and subclasses of cerebellar tumors that may merit individualized targeting. One recent series of cHGG included the subclasses of (1) high-grade astrocytoma with piloid features (HGAP, ~31% of tumors); (2) H3K27M diffuse midline glioma (~8%); and (3) isocitrate dehydrogenase (IDH) wildtype glioblastoma (~43%). The latter had an unusually low-frequency of epidermal growth factor receptor (EGFR) and high-frequency of platelet-derived growth factor receptor alpha (PDGFRA) amplification, reflecting a different composition of methylation classes compared to supratentorial IDH-wildtype tumors. These new classifications have begun to reveal insights into the pathogenesis of HGG in the cerebellum and lead toward individualized treatment targeted toward the appropriate subclass of cHGG. Emerging therapeutic strategies include targeting the mitogen-activated protein kinases (MAPK) pathway and PDGFRA, oncolytic virotherapy, and immunotherapy. HGGs of the cerebellum exhibit biological differences compared to sHGG, and improved understanding of their molecular subclasses has the potential to advance treatment.

Unexpected Prolonged Survival in a Case of Cerebellar GBM: An Interesting Case with Literature Review

Glioblastoma multiforme (GBM) of cerebellar hemisphere is a rare entity and constitutes less than 1% of all the GBMs. The rarity of occurrence leads to significant challenge in differentiating morphologically from other subtypes of glioma in the posterior fossa. Previous studies have suggested that cerebellar GBM occurs in the younger age group as compared with the supratentorial counterpart.

Here, we report a case of cerebellar GBM in a young adult and discuss the pathogenesis including radiological and pathological aspects involved in the treatment of cerebellar GBM.

Rapid Brainstem Infiltration of a Cerebellar Glioblastoma

A 79-year-old female complained of a one-month history of imbalance and headache. Brain MRI showed an irregular rim enhancing solid and cystic mass centered in the superomedial left cerebellar hemisphere. Resection of the lesion was recommended; however, the patient opted to undergo the procedure the following month because of the nearby Christmas holidays. When the patient returned 30 days later, a new brain MRI showed an enlargement of the cerebellar mass, extending to the brainstem and infiltrating the left brachium pontis, left posterior aspect of the tegmentum of the pons, and posterolateral medulla oblongata. Subtotal resection was performed without complications, and pathology was compatible with a primary cerebellar glioblastoma negative for IDH1/2 gene mutation. Because of the poor prognosis, the patient and her family members opted for hospice treatment, with the patient dying three weeks later. This case illustrates that cerebellar glioblastoma can rapidly infiltrate the brainstem.

Systematic Review of Racial, Socioeconomic, and Insurance Status Disparities in Neurosurgical Care for Intracranial Tumors

BACKGROUND

The impact of race, socioeconomic status (SES), insurance status, and other social metrics on the outcomes of patients with intracranial tumors has been reported in several studies. However, these findings have not been comprehensively summarized.

METHODS

We conducted a PRISMA systematic review of all published articles between 1990 and 2020 that analyzed intracranial tumor disparities, including race, SES, insurance status, and safety-net hospital status. Outcomes measured include access, standards of care, receipt of surgery, extent of resection, mortality, complications, length of stay (LOS), discharge disposition, readmission rate, and hospital charges.

RESULTS

Fifty-five studies were included. Disparities in mortality were reported in 27 studies (47%), showing minority status and lower SES associated with poorer survival outcomes in 14 studies (52%). Twenty-seven studies showed that African American patients had worse outcomes across all included metrics including mortality, rates of surgical intervention, extent of resection, LOS, discharge disposition, and complication rates. Thirty studies showed that privately insured patients and patients with higher SES had better outcomes, including lower mortality, complication, and readmission rates. Six studies showed that worse outcomes were associated with treatment at safety-net and/or low-volume hospitals. The influence of Medicare or Medicaid status, or inequities affecting other minorities, was less clearly delineated. Ten studies (18%) were negative for evidence of disparities.

CONCLUSIONS

Significant disparities exist among patients with intracranial tumors, particularly affecting patients of African American race and lower SES. Efforts at the hospital, state, and national level must be undertaken to identify root causes of these issues.

Nomograms for predicting the overall survival of patients with cerebellar glioma: an analysis of the surveillance epidemiology and end results (SEER) database

At present, our understanding of cerebellar glioma is still insufficient. This study collected information on patients in the SEER database to identify the predictive factors for patients with cerebellar glioma. Data from patients with cerebellar glioma diagnosed from 1975 to 2018 were retrieved from the Surveillance Epidemiology and End Results Database. We randomly divided the patients into a training group and a validation group, established a nomogram based on the training group, and used the validation group data to verify the clinical value of the model. A total of 508 patients were included in this study. Multivariate analysis was performed based on the data before randomization, and the results showed that the patient's age, WHO grade, histological type, and extent were significantly correlated with the survival rate. The C-index of the OS nomograms of the training cohort was 0.909 (95% CI, (0.880–0.938)) and 0.932 (95% CI, (0.889–0.975)) in the validation group. The calibration curve of OS for 3 and 5 years showed that there was good consistency between the actual survival probability and the predicted survival probability. For patients with cerebellar glioma, the age at diagnosis, WHO grade of the glioma, histological type, and extension are the four factors that most strongly affect the overall survival outcomes. Furthermore, our model may be a useful tool for predicting OS in these patients.

Characteristics and management of hydrocephalus in adult patients with cerebellar glioblastoma: lessons from a French nationwide series of 118 cases

The characteristics of hydrocephalus associated with cerebellar glioblastoma (cGB) remain poorly known. The objectives were to describe the occurence of hydrocephalus in a French nationwide series of adult patients with cGB, to identify the characteristics associated with hydrocephalus and to analyze the outcomes associated with the different surgical strategies, in order to propose practical guidelines. Consecutive cases of adult cGB patients prospectively recorded into the French Brain Tumor Database between 2003 and 2017 were screened. Diagnosis was confirmed by a centralized neuropathological review. Among 118 patients with cGB (mean age 55.9 years), 49 patients (41.5%) presented with pre-operative hydrocephalus. Thirteen patients (11.0%) developed acute (n=7) or delayed (n=6) hydrocephalus postoperatively. Compared to patients without hydrocephalus at admission, patients with hydrocephalus were younger (52.0 years vs 58.6 years, p=0.03) and underwent more frequently tumor resection (93.9% vs 73.9%, p=0.006). A total of 40 cerebrospinal-fluid diversion procedures were performed, including 18 endoscopic third ventriculostomies, 12 ventriculoperitoneal shunts and 10 external ventricular drains. The different cerebrospinal-fluid diversion options had comparable functional results and complication rates. Among the 89 patients surgically managed for cGB without prior cerebrospinal-fluid diversion, 7 (7.9%) were long-term shunt-dependant. Hydrocephalus is frequent in patients with cGB and has to be carefully managed in order not to interfere with adjuvant oncological treatments. In case of symptomatic hydrocephalus, a cerebrospinal-fluid diversion is mandatory, especially if surgical resection is not feasible. In case of asymptomatic hydrocephalus, a cerebrospinal-fluid diversion has to be discussed only if surgical resection is not feasible.

Outcomes of infratentorial cranial surgery for tumor resection in older patients: An analysis of the National Surgical Quality Improvement Program

Background:

Poorer outcomes for infratentorial tumor resection have been reported. There is a lack of large multicenter analyses describing infratentorial surgery outcomes in older patients. We characterized outcomes in patients aged ≥65 years undergoing infratentorial cranial surgery.

Methods:

The National Surgical Quality Improvement Project database was queried from 2012 to 2018 for patients ≥18 years undergoing elective infratentorial cranial surgery for tumor resection. Patients were grouped into 65–74 years, ≥75 years, and 18–64 years cohorts. Multivariable regressions compared outcome measures.

Results:

Of 2212 patients, 28.3% were ≥65 years, of whom 24.8% were ≥75 years. Both older subpopulations had worse American Society of Anesthesiologists classification compared to controls (P < 0.01) and more comorbidities. Patients 65–74 and ≥75 years had higher rates of major complication (adjusted odds ratio [aOR] = 1.77, 95% CI = 1.13–2.79 and aOR = 3.44, 95% CI = 1.96–6.02, respectively), prolonged length of stay (LOS) (aOR = 1.89, 95% CI = 1.15–3.12 and aOR = 3.00, 95% CI = 1.65–5.44, respectively), and were more likely to be discharged to a location other than home (aOR = 2.43, 95% CI =1.73–3.4 and aOR = 3.41, 95% CI = 2.18–5.33, respectively) relative to controls. Patients ≥75 had higher rates of readmission (aOR = 1.86, 95% CI = 1.13–3.08) and mortality (aOR = 3.28, 95% CI = 1.21–8.89) at 30 days.

Conclusion:

Patients ≥65 years experienced more complications, prolonged LOS, and were less often discharged home than adults <65 years. Patients ≥75 years had higher rates of 30-day readmission and mortality. There is a need for careful preoperative optimization in older patients undergoing infratentorial tumor cranial surgery.

Targeting Protein Kinase C in Glioblastoma Treatment

Glioblastoma (GBM) is the most frequent and aggressive primary brain tumor and is associated with a poor prognosis. Despite the use of combined treatment approaches, recurrence is almost inevitable and survival longer than 14 or 15 months after diagnosis is low. It is therefore necessary to identify new therapeutic targets to fight GBM progression and recurrence. Some publications have pointed out the role of glioma stem cells (GSCs) as the origin of GBM. These cells, with characteristics of neural stem cells (NSC) present in physiological neurogenic niches, have been proposed as being responsible for the high resistance of GBM to current treatments such as temozolomide (TMZ). The protein Kinase C (PKC) family members play an essential role in transducing signals related with cell cycle entrance, differentiation and apoptosis in NSC and participate in distinct signaling cascades that determine NSC and GSC dynamics. Thus, PKC could be a suitable druggable target to treat recurrent GBM. Clinical trials have tested the efficacy of PKCβ inhibitors, and preclinical studies have focused on other PKC isozymes. Here, we discuss the idea that other PKC isozymes may also be involved in GBM progression and that the development of a new generation of effective drugs should consider the balance between the activation of different PKC subtypes.

Real-world validity of randomized controlled phase III trials in newly diagnosed glioblastoma: to whom do the results of the trials apply?

Background

The survival rates in population-based series of glioblastoma (GBM) differ substantially from those reported in clinical trials. This discrepancy may be attributed to that patients recruited to trials tend to be younger with better performance status. However, the proportion and characteristics of the patients in a population considered either eligible or ineligible for trials is unknown. The generalizability of trial results is therefore also uncertain.

Methods

Using the Cancer Registry of Norway and the Brain Tumor Database at Oslo University Hospital, we tracked all patients within a well-defined geographical area with newly diagnosed GBM during the years 2012–2017. Based on data from these registries and the medical records, the patients were evaluated for trial eligibility according to criteria employed in recent phase III trials for GBM.

Results

We identified 512 patients. The median survival was 11.7 months. When we selected a potential trial population at the start of concurrent chemoradiotherapy (radiotherapy [RT]/ temozolomide [TMZ]) by the parameters age (18–70 y), passed surgery for a supratentorial GBM, Eastern Cooperative Oncology Group (ECOG) ≤2, normal hematologic, hepatic and renal function, and lack of severe comorbidity, 57% of the patients were excluded. Further filtering the patients who progressed during RT/TMZ and never completed RT/TMZ resulted in exclusion of 59% and 63% of the patients, respectively. The survival of patients potentially eligible for trials was significantly higher than of the patients not fulfilling trial eligibility criteria (P < .0001).

Conclusions

Patients considered eligible for phase III clinical trials represent a highly selected minority of patients in a real-world GBM population.

The many faces of glioblastoma: Pictorial review of atypical imaging features

Glioblastoma is an aggressive primary central nervous system tumour that usually has a poor prognosis. Generally, the typical imaging features are easily recognisable, but the behaviour of glioblastoma multiforme (GBM) can often be unusual. Several variations and heterogeneity in GBM appearance have been known to occur. In this pictorial essay, we present cases of pathologically confirmed GBM that illustrate unusual locations and atypical features on neuroimaging, and review the relevant literature. Even innocuous-looking foci, cystic lesions, meningeal-based pathology, intraventricular and infra-tentorial masses, multifocal/multicentric lesions and spinal cord abnormalities may represent GBM. We aim to highlight the atypical characteristics of glioblastoma, clarify their importance and list the potential mimickers. Although a definitive diagnosis in these rare cases of GBM warrants histopathological confirmation, an overview of the many imaging aspects may help make an early diagnosis.

Management, functional outcomes and survival in a French multicentric series of 118 adult patients with cerebellar glioblastoma

PURPOSE

To analyze the outcomes and predictors in a large series of cerebellar glioblastomas in order to guide patient management.

METHODS

The French brain tumor database and the Club de Neuro-Oncologie of the Société Française de Neurochirurgie retrospectively identified adult patients with cerebellar glioblastoma diagnosed between 2003 and 2017. Diagnosis was confirmed by a centralized neuropathological review.

RESULTS

Data from 118 cerebellar glioblastoma patients were analyzed (mean age 55.9 years, 55.1% males). The clinical presentation associated raised intracranial pressure (50.8%), static cerebellar syndrome (68.6%), kinetic cerebellar syndrome (49.2%) and/or cranial nerve disorders (17.8%). Glioblastomas were hemispheric (55.9%), vermian (14.4%) or both (29.7%). Hydrocephalus was present in 49 patients (41.5%). Histologically, tumors corresponded either to IDH-wild-type or to K27-mutant glioblastomas. Surgery consisted of total (12.7%), subtotal (35.6%), partial resection (33.9%) or biopsy (17.8%). The postoperative Karnofsky performance status was improved, stable and worsened in 22.4%, 43.9% and 33.7% of patients, respectively. Progression-free and overall survivals reached 5.1 months and 9.1 months, respectively. Compared to other surgical strategies, total or subtotal resection improved the Karnofsky performance status (33.3% vs 12.5%, p < 0.001), prolonged progression-free and overall survivals (6.5 vs 4.3 months, p = 0.015 and 16.7 vs 6.2 months, p < 0.001, respectively) and had a comparable complication rate (40.4% vs 31.1%, p = 0.29). After total or subtotal resection, the functional outcomes were correlated with age (p = 0.004) and cerebellar hemispheric tumor location (p < 0.001) but not brainstem infiltration (p = 0.16).

CONCLUSION

In selected patients, maximal resection of cerebellar glioblastoma is associated with improved onco-functional outcomes, compared with less invasive procedures.

Comparative Analysis of Survival Outcomes and Prognostic Factors of Supratentorial versus Cerebellar Glioblastoma in the Elderly: Does Location Really Matter?

BACKGROUND

Cerebellar glioblastomas (cGBMs) are rare tumors that are uncommon in the elderly. In this study, we compare survival outcomes and identify prognostic factors of cGBM compared with the supratentorial (stGBM) counterpart in the elderly.

METHODS

Data from the SEER 18 registries were used to identify patients with a glioblastoma (GBM) diagnosis between 2000 and 2016. The log-rank method and a multivariable Cox proportional hazards regression model were used for analysis.

RESULTS

Among 110 elderly patients with cGBM, the median age was 74 years (interquartile range [IQR], 69-79 years), 39% were female and 83% were white. Of these patients, 32% underwent gross total resection, 73% radiotherapy, and 39% chemotherapy. Multivariable analysis of the unmatched and matched cohort showed that tumor location was not associated with survival; in the unmatched cohort, insurance status (hazard ratio [HR], 0.11; IQR, 0.02-0.49; P = 0.004), gross total resection (HR, 0.53; IQR, 0.30-0.91; P = 0.022), and radiotherapy (HR, 0.33; IQR, 0.18-0.61; P < 0.0001) were associated with better survival. Patients with cGBM and stGBM undergoing radiotherapy (7 months vs. 2 months; P < 0.001) and chemotherapy (10 months vs. 3 months; P < 0.0001) had improved survival. Long-term mortality was lower for cGBM in the elderly at 24 months compared with the stGBM cohort (P = 0.007).

CONCLUSIONS

In our study, elderly patients with cGBM and stGBM have similar outcomes in overall survival, and those undergoing maximal resection with adjuvant therapies, independent of tumor location, have improved outcomes. Thus, aggressive treatment should be encouraged for cGBM in geriatric patients to confer the same survival benefits seen in stGBM. Single-institutional and multi-institutional studies to identify patient-level prognostic factors are warranted to triage the best surgical candidates.

Treatment patterns and outcomes for cerebellar glioblastoma in the concomitant chemoradiation era: A National Cancer database study

Cerebellar glioblastoma (GB) is much rarer than its supratentorial counterpart, and potentially of different molecular origin. Prior database studies are of limited size and reported on patients who preceded the validation of temozolomide. Thus, we provide an updated population-based analysis of the treatment trends and outcomes since the standardization of GB adjuvant chemoradiation. Patients diagnosed with primary cerebellar and supratentorial GB were identified from the National Cancer Database spanning 2005-2015. Patients were characterized by demographics, extent of resection, and adjuvant chemotherapy or radiation status. Cohorts were primarily and secondarily assessed for overall survival by tumor site and treatment history, respectively. A total of 655 patients with cerebellar GB were identified (0.6%). Cerebellar GB patients, compared to supratentorial GB were more likely to undergo a biopsy or subtotal resection (13.4% vs 9.3% and 16.0% vs 13.4%, p-value < 0.001), and less likely to pursue adjuvant therapy (48.4% vs 52.7%, p-value < 0.001). Overall median survivals were 9.3 and 9.4 months, respectively. On multivariable analysis, gross total resection, radiation, and chemotherapy were found to be predictors of improved overall survival (HR 0.77, p = 0.038; HR 0.67, p < 0.001; and HR = 0.77, p = 0.030, respectively). While many management principles are currently shared between cerebellar and supratentorial GB, aggressive regimens appear less frequently prescribed. Survival continues to match supratentorial outcomes and may benefit from future, systemic guidance by distinguishing molecular features.

A Rare Case of Cerebellar Glioblastoma Mimicking Acute Stroke in an Elderly Patient

Patient: Female, 82-year-old

Final Diagnosis: Cerebellar glioblastoma

Symptoms: Dizziness

Medication: —

Clinical Procedure: —

Specialty: Neurology

Advances in drug delivery technology for the treatment of glioblastoma multiforme

Glioblastoma multiforme (GBM) is a particularly aggressive and malignant type of brain tumor, notorious for its high recurrence rate and low survival rate. The treatment of GBM is challenging mainly because several issues associated with the GBM microenvironment have not yet been resolved. These obstacles originate from a variety of factors such as genetics, anatomy, and cytology, all of which collectively hinder the treatment of GBM. Recent advances in materials and device engineering have presented new perspectives with regard to unconventional drug administration methods for GBM treatment. Such novel drug delivery approaches, based on the clear understanding of the intrinsic properties of GBM, have shown promise in overcoming some of the obstacles. In this review, we first recapitulate the first-line therapy and clinical challenges in the current treatment of GBM. Afterwards, we introduce the latest technological advances in drug delivery strategies to improve the efficiency for GBM treatment, mainly focusing on materials and devices. We describe such efforts by classifying them into two categories, systemic and local drug delivery. Finally, we discuss unmet challenges and prospects for the clinical translation of these drug delivery technologies.

Comparative epidemiology of gliosarcoma and glioblastoma and the impact of Race on overall survival: A systematic literature review

OBJECTIVE

Gliosarcoma (GSM) is a rare subtype of glioblastoma (GBM) that accounts for approximately four percent of high-grade gliomas. There is scarce epidemiological data on patients with GSM as a distinct subgroup of GBM.

METHODS

A systematic literature review was performed of peer-reviewed databases using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to evaluate the impact of race and ethnicity on survival in patients with GSM compared to patients with GBM.

RESULTS

Following initial abstract screening, a total of 138 articles pertaining to GSM and 275 pertaining to GBM met criteria for full-text review, with 5 and 27 articles included in the final analysis for GSM and GBM, respectively. The majority of patients in both cohorts were non-Hispanic Whites, representing 85.6 % of total GSM patients and 87.7 % of GBM patients analyzed. Two GSM studies stratified survival by race, with one reporting the longest median survival for the Hispanic population of 10.6 months and the shortest median survival for the Asian population of 9 months. Among the GBM studies analyzed, the majority of studies reported shorter survival and higher risk of mortality among White Non-Hispanics compared to non-White patients; and of the 15 studies which reported data for the Asian population, 12 studies reported this race category to have the longest survival compared to all other races studied. Younger age, female sex, MGMT promoter methylation status, and adjuvant chemoradiation therapy were associated with improved survival in both GSM and GBM cohorts, although these were not further stratified by race.

CONCLUSION

GSM portends a similarly poor prognosis to other GBM subtypes; however, few studies exist which have examined factors associated with differences in survival between these histologic variants. This review of the literature suggests there is a possible association between race and survival for patients with GBM, however data supporting this conclusion for patients with GSM is lacking. These findings suggest that GSM is a distinct disease from other GBM subtypes, with epidemiologic differences that should be further explored.

Treatment and surgical factors associated with longer-term glioblastoma survival: a National Cancer Database study

Background

Insufficient data exist to characterize factors associated with longer-term survival of glioblastoma (GBM). A population-based analysis of GBM longer-term survivors (LTS) in the United States was conducted to investigate the association between treatment, demographic, surgical factors, and longer-term survival.

Methods

From the National Cancer Database, GBM patients were identified using ICD-O-3 histology codes 9440-9442/3, 2005-2015 and were divided into routine (≤3 years) and longer-term (>3 years) overall survival (OS) groups. Univariable and multivariable logistic regression analysis was used to assess factors associated with longer-term survival. A subset analysis was performed to further investigate the association of extent of resection and treatment combinations on OS outcomes.

Results

A total of 93 036 patients with GBM met study criteria. Among these patients, 8484 were LTS and 84 552 were routine survivors (RS). When comparing LTS (OS of >3 years) with RS (OS of ≤3 years), younger age, insured status, metro/urban residence, treatment at academic facility, and fewer comorbidities were associated with longer-term survival. In addition, trimodality therapy (chemotherapy + radiation + surgery) was associated with having best odds of longer-term survival (odds ratio = 4.89, 95% confidence interval [3.58, 6.68]); 74% of LTS received such therapy compared with 51% of RS. Subset analysis revealed that total resection is only associated with longer-term survival status for those receiving trimodality therapy or surgery only.

Conclusions

In a population-based analysis, standard of care surgery and chemo radiation connote a survival advantage in GBM. Among those receiving standard of care, having a total resection is most beneficial for longer-term survival status.

Distinct genomic profile and specific targeted drug responses in adult cerebellar glioblastoma

Background

Despite extensive efforts on the genomic characterization of gliomas, very few studies have reported the genetic alterations of cerebellar glioblastoma (C-GBM), a rare and lethal disease. Here, we provide a systematic study of C-GBM to better understand its specific genomic features.

Methods

We collected a cohort of C-GBM patients and compared patient demographics and tumor pathologies with supratentorial glioblastoma (S-GBM). To uncover the molecular characteristics, we performed DNA and mRNA sequencing and DNA methylation arrays on 19, 6, and 4 C-GBM cases, respectively. Moreover, chemical drug screening was conducted to identify potential therapeutic options for C-GBMs.

Results

Despite differing anatomical origins of C-GBM and S-GBM, neither histological, cytological, nor patient demographics appeared significantly different between the 2 types. However, we observed striking differences in mutational patterns, including frequent alterations of ATRX, PDGFRA, NF1, and RAS and absence of EGFR alterations in C-GBM. These results show a distinct evolutionary path in C-GBM, suggesting specific therapeutic targeted options. Targeted-drug screening revealed that C-GBMs were more responsive to mitogen-activated protein kinase kinase (MEK) inhibitor and resistant to epidermal growth factor receptor inhibitors than S-GBMs. Also, differential expression analysis indicated that C-GBMs may have originated from oligodendrocyte progenitor cells, suggesting that different types of cells can undergo malignant transformation according to their location in brain. Master regulator analysis with differentially expressed genes between C-GBM and proneural S-GBM revealed NR4A1 as a potential therapeutic target.

Conclusions

Our results imply that unique gliomagenesis mechanisms occur in adult cerebellum and new treatment strategies are needed to provide greater therapeutic benefits for C-GBM patients.

Key Points

1. Distinct genomic profiles of 19 adult cerebellar GBMs were characterized. 2. MEK inhibitor was highly sensitive to cerebellar GBM compared with supratentorial GBM. 3. Master regulator analysis revealed NR4A1 as a potential therapeutic target in cerebellar GBM.

Gliomatosis cerebri (GC) or GC-like? A picture to be reconsidered in neuro-oncology based on large retrospective analysis of GC series

INTRODUCTION

Gliomatosis cerebri (GC), defined until 2016 as a distinct astrocytic glioma entity, has been removed from the 2016 World Health Organization classification of tumors of the central nervous system. However, its identity is still debated.

MATERIALS AND METHODS

We retrospectively present 122 patients, including a subgroup with histology confirmation (n = 75, cohort b).

RESULTS

Radiological features showed extension limited to 3 lobes in 31%; bilateral, midline, and basal ganglia and subtentorial involvement in 95%, 52%, 84%, and 60%, respectively; and contrast enhancement in 59.5%. Perioperative mortality occurred in 4%. Histology concluded for grades II, III, and IV, respectively, in 31%, 35%, and 22% (not specified in 12%). Thirty-one percent had isocitrate dehydrogenase (IDH) 1 mutation. Treatments included radiotherapy in 51.2% and chemotherapy in 74.5%. Median overall survival was 17 months. Negative prognostic factors for survival were older age, poorer Karnofsky Performance Scale (KPS), subtentorial, midline and disseminated disease, and lack of chemotherapy, at univariate analysis. At multivariate analysis, KPS ≥ 80, chemotherapy, and subtentorial and disseminated disease remained prognostic (p < 0.0001). For cohort b, same prognostic factors were confirmed, except for midline location, at univariate analysis; at multivariate analysis, only KPS ≥ 80 and chemotherapy remained prognostic (p < 0.0001).

CONCLUSION

We described clinical, neuroimaging, management, and histomolecular features of one of the largest GC series. We identified KPS ≥ 80, radiological pattern as subtentorial localization and dissemination, and chemotherapy as prognostic factors, at multivariate analysis. Planning prospective study, associated to focused genetic assays, could help to clarify if GC has specific features that may result in the identification as a separate entity from other gliomas.

Characteristics and prognostic factors of age-stratified high-grade intracranial glioma patients: A population-based analysis

We evaluated characteristics and different prognostic factors for survival in age-stratified high-grade glioma in a U.S. cohort. Eligible patients were identified in the Surveillance, Epidemiology, and End Results (SEER) registries and stratified into 3 age groups: 20-39 years old (1,043 patients), 40-59 years old (4,503 patients), and >60 years old (5,045 patients). Overall and cancer-related survival data were obtained. Cox models were built to analyze the outcomes and risk factors. It showed that race was a prognostic factor for survival in patients 40 to 59 years old and in patients ≥60 years old. Partial resection was associated with lower overall survival and cause-specific survival in all age groups (overall survival: 20-39 yr: HR = 6.41; 40-59 yr: HR = 4.84; >60 yr: HR = 5.06; cause-specific survival: 20-39 yr: HR = 5.87; 40-59 yr: HR = 4.01; >60 yr: HR = 3.36). The study highlights that, while some prognostic factors are universal, others are age-dependent. The effectiveness of treatment approaches differs for patients in different age groups. Results of this study may help to develop personalized treatment protocols for glioma patients of different ages.

Tumors diagnosed as cerebellar glioblastoma comprise distinct molecular entities

In this multi-institutional study we compiled a retrospective cohort of 86 posterior fossa tumors having received the diagnosis of cerebellar glioblastoma (cGBM). All tumors were reviewed histologically and subjected to array-based methylation analysis followed by algorithm-based classification into distinct methylation classes (MCs). The single MC containing the largest proportion of 25 tumors diagnosed as cGBM was MC anaplastic astrocytoma with piloid features representing a recently-described molecular tumor entity not yet included in the WHO Classification of Tumours of the Central Nervous System (WHO classification). Twenty-nine tumors molecularly corresponded to either of 6 methylation subclasses subsumed in the MC family GBM IDH wildtype. Further we identified 6 tumors belonging to the MC diffuse midline glioma H3 K27 M mutant and 6 tumors allotted to the MC IDH mutant glioma subclass astrocytoma. Two tumors were classified as MC pilocytic astrocytoma of the posterior fossa, one as MC CNS high grade neuroepithelial tumor with BCOR alteration and one as MC control tissue, inflammatory tumor microenvironment. The methylation profiles of 16 tumors could not clearly be assigned to one distinct MC. In comparison to supratentorial localization, the MC GBM IDH wildtype subclass midline was overrepresented, whereas the MCs GBM IDH wildtype subclass mesenchymal and subclass RTK II were underrepresented in the cerebellum. Based on the integration of molecular and histological findings all tumors received an integrated diagnosis in line with the WHO classification 2016. In conclusion, cGBM does not represent a molecularly uniform tumor entity, but rather comprises different brain tumor entities with diverse prognosis and therapeutic options. Distinction of these molecular tumor classes requires molecular analysis. More than 30% of tumors diagnosed as cGBM belong to the recently described molecular entity of anaplastic astrocytoma with piloid features.

Malignant Glioma in the Cerebellum Presenting as Multiple Small Lesions

Malignant glioma, the most common malignant primary brain tumor in adults, usually occurs in supratentorial space as a single mass lesion, and cerebellar location and multiple appearance are uncommon. We report a case of a 69-year-old female with three lesions simultaneously found in the cerebellum on magnetic resonance images (MRIs) after suffering from gait disturbance. Two lesions were around 15 mm in size and the other one was observed as a spotty enhancement. Although MRI findings suggested brain metastases, whole body examinations denied any primary malignancies. Biopsy for one lesion in the cerebellum was performed, which resulted in pathological diagnosis of malignant astrocytoma. The lesions were considered multicentric glioma based on MRI definition. The treatment with temozolomide and whole brain radiation was completed. Although the patient was discharged in an independent state with the shrinkage of the tumors, she unexpectedly died following sudden loss of consciousness from an unknown cause one month after discharge. The coincidence of cerebellar location and multicentricity characterized by smallness is quite rare in glioma patients, and such MRI findings might be misleading for the diagnosis. We describe the details of the case and discuss the pathogenesis of this unique presentation of malignant glioma with the literatures.

Cerebellar glioblastoma: a clinical series with contemporary molecular analysis

BACKGROUND

Glioblastomas (GBM) are localized in only less than 1% of patients in the cerebellum. Therefore, tumor characteristics, survival, and the efficacy of therapies are not yet well defined. The present study aims to characterize the molecular features of cerebellar GBM (GBMc) in 8 patients treated with contemporary modality in our institution.

METHODS

Patients' treatment history, progression-free survival (PFS), and overall survival (OS) were analyzed. All histopathological specimens were re-investigated. EGFR amplification was determined by FISH, H3F3A, and HIST1H3B mutation status and MGMT promoter methylation after bisulfite treatment by pyrosequencing and BRAF V600E by pyrosequencing and immunohistochemistry. TERT promoter mutations were analyzed by Sanger sequencing, CDKN2A/B deletions by digital PCR. The expression of IDH1 R132H, ATRX, and p53 was determined through immunohistochemistry.

RESULTS

Six adults and two children (mean age 36 years) underwent tumor resection via medial or lateral suboccipital craniotomy. The median overall survival (mOS) of the adult patients was 7 months. GBMc from two children demonstrated a H3F3A K27M mutation. One of these also harbored a BRAF V600E mutation and has already had a PFS of 74 months. Mutated IDH1 R132H protein was expressed in 2 GBM from adult patients with previous supratentorial anaplastic astrocytoma. One patient carried a TERT promoter mutation. Another patient initially presented with a thalamic pilocytic astrocytoma. The cerebellar tumor revealed neither a BRAF V600E nor a H3F3A mutation but a homozygous CDKN2A/B deletion.

CONCLUSIONS

GBM located in the cerebellum can be found in all age groups. We provide novel molecular genetic data on these rare tumors. Mutated IDH1 R132H protein and H3F3A K27M mutations indicate that a substantial number of GBMc are "metastatic" or "diaschismatic" lesions. Mutation of BRAF V600E may have a stronger biological significance than H3F3A K27M alterations. In a subset of patients, GBM may arise primarily as a distinct entity in the cerebellum.

A Primary Cerebellar Glioblastoma Multiforme Mimicking Vestibular Schwannoma

Cerebellar glioblastoma multiforme (cGBM) is rare in adults, accounting for <1% of all patients with glioblastoma multiforme (GBM). The accurate diagnosis of cGBM is important for establishing a suitable therapeutic schedule. However, the diagnosis of cerebellar GBM is not usually suspected preoperatively because of its rarity. Generally, patients with cGBMs typically presented with symptoms of raised intracranial pressure, and infrequently cerebellar symptoms such as gait ataxia and disequilibrium. Nevertheless, the authors reported a cGMB patient, with his clinical presentations and imaging characteristics mimicking a vestibular schwannoma. To the best of our knowledge, this is the first reported patient with cGBM mimicking a vestibular schwannoma. Furthermore, the diagnosis, treatment, and prognosis for cGBM were broadly investigated.

Distinct molecular profile of diffuse cerebellar gliomas

Recent studies have demonstrated that tumor-driving alterations are often different among gliomas that originated from different brain regions and have underscored the importance of analyzing molecular characteristics of gliomas stratified by brain region. Therefore, to elucidate molecular characteristics of diffuse cerebellar gliomas (DCGs), 27 adult, mostly glioblastoma cases were analyzed. Comprehensive analysis using whole-exome sequencing, RNA sequencing, and Infinium methylation array (n = 17) demonstrated their distinct molecular profile compared to gliomas in other brain regions. Frequent mutations in chromatin-modifier genes were identified including, noticeably, a truncating mutation in SETD2 (n = 4), which resulted in loss of H3K36 trimethylation and was mutually exclusive with H3F3A K27M mutation (n = 3), suggesting that epigenetic dysregulation may lead to DCG tumorigenesis. Alterations that cause loss of p53 function including TP53 mutation (n = 9), PPM1D mutation (n = 2), and a novel type of PPM1D fusion (n = 1), were also frequent. On the other hand, mutations and copy number changes commonly observed in cerebral gliomas were infrequent. DNA methylation profile analysis demonstrated that all DCGs except for those with H3F3A mutations were categorized in the "RTK I (PDGFRA)" group, and those DCGs had a gene expression signature that was highly associated with PDGFRA. Furthermore, compared with the data of 315 gliomas derived from different brain regions, promoter methylation of transcription factors genes associated with glial development showed a characteristic pattern presumably reflecting their tumor origin. Notably, SOX10, a key transcription factor associated with oligodendroglial differentiation and PDGFRA regulation, was up-regulated in both DCG and H3 K27M-mutant diffuse midline glioma, suggesting their developmental and biological commonality. In contrast, SOX10 was silenced by promoter methylation in most cerebral gliomas. These findings may suggest potential tailored targeted therapy for gliomas according to their brain region, in addition to providing molecular clues to identify the region-related cellular origin of DCGs.

Histone H3 K27M mutations in adult cerebellar high-grade gliomas

Adult cerebellar high-grade gliomas (HGG) are rare and their molecular basis has not been fully elucidated. Although a diffuse midline glioma H3 K27M-mutant, a recently characterized variant of HGG, was reported to occasionally occur in the cerebellum, adult cases were rarely tested for this mutation; only five mutant cases have been reported to date. It currently remains unknown whether H3 K27M-mutant cerebellar gliomas share common histological features or have a uniformly dismal prognosis. In the present study, we assessed the prevalence of histone H3 K27M mutations in ten adult cerebellar HGG, identifying two H3F3A-mutant cases. One case was a 70-year-old female with a cystic lesion. Histologically, the tumor was considered to be glioblastoma; however, a part of the tumor exhibiting low proliferative activity appeared to be consistent with long-standing H3 K27M-mutant tumors in the literature. Another case was a 69-year-old male. The tumor showed a distinct circumscribed histology with minimal astrocytic differentiation, suggesting a nosological issue in the diagnosis of diffuse midline glioma. More cerebellar tumors need to be tested for H3 K27M mutations to clarify the clinical and histopathological spectra of this tumor.

Posterior Fossa Intra-Axial Tumors in Adults

BACKGROUND

The posterior fossa is the site of many types of tumors, and brain metastases are the most common malignancies in that location among adults. Other brain tumors, such as ependymomas, medulloblastomas, and juvenile pilocytic astrocytomas, mostly occur during childhood and are relatively rare in adults. Most primary malignant brain tumors, such as gliomas and lymphomas, tend to be located in the supratentorial compartment.

METHODS

This review summarizes prognostic factors, therapeutic management, and molecular data of intra-axial posterior fossa tumors in adults, including ependymomas, medulloblastomas, and pilocytic astrocytomas.

RESULTS

The literature on intra-axial posterior fossa tumors in adults relies mainly on limited retrospective clinical studies, and such studies employ a wide range of treatment approaches that are usually based on therapies developed specifically for children or for supratentorial brain tumors.

CONCLUSIONS

The clinical course and surgical outcome of adult patients with intra-axial brain tumors in the posterior fossa are summarized in this review. The prognostic factors and therapeutic management of patients with these tumors are controversial because of their rarity, their heterogeneity, and the lack of sufficient data in the literature.

Patient and treatment factors associated with survival among adult glioblastoma patients: A USA population-based study from 2000-2010

In this study, we utilized the USA surveillance, epidemiology, and end results (SEER) database to examine factors influencing survival of glioblastoma multiforme (GBM) patients. GBM is the most common primary malignant brain tumor in adults and despite advances in treatment, prognosis remains poor. Using the SEER database, we defined a cohort of adult patients for the years 2000-2009 with confirmed GBM and minimum follow-up of 12 months. A total of 14,675 patients with GBM met the inclusion criteria. Demographic, clinical, and treatment variables were examined. Death was the primary outcome. Median survival time was 11 months. Patients had increasingly longer survival over the decade span. We found, on multivariate analysis, that significantly worse survival was associated with age >75 years, male sex, unmarried status, and non-Hispanic Caucasian race/ethnicity. Patients in the Northeast had a significantly lower risk of mortality. Patients with tumors that were non-lateralized and >3 cm fared worse. Patients who did not receive adjuvant radiation also had worse outcomes. Gross total resection imparted a survival advantage for patients compared to biopsy or partial resection. Thus, this report adds to the growing body of literature supporting the positive role of maximal resection on patient survival.

Epidemiologic and molecular prognostic review of glioblastoma

Glioblastoma multiforme (GBM) is the most common and aggressive primary central nervous system malignancy with a median survival of 15 months. The average incidence rate of GBM is 3.19/100,000 population, and the median age of diagnosis is 64 years. Incidence is higher in men and individuals of white race and non-Hispanic ethnicity. Many genetic and environmental factors have been studied in GBM, but the majority are sporadic, and no risk factor accounting for a large proportion of GBMs has been identified. However, several favorable clinical prognostic factors are identified, including younger age at diagnosis, cerebellar location, high performance status, and maximal tumor resection. GBMs comprise of primary and secondary subtypes, which evolve through different genetic pathways, affect patients at different ages, and have differences in outcomes. We report the current epidemiology of GBM with new data from the Central Brain Tumor Registry of the United States 2006 to 2010 as well as demonstrate and discuss trends in incidence and survival. We also provide a concise review on molecular markers in GBM that have helped distinguish biologically similar subtypes of GBM and have prognostic and predictive value.

Glioma virus therapies between bench and bedside

Despite extensive research, current glioma therapies are still unsatisfactory, and novel approaches are pressingly needed. In recent years, both nonreplicative viral vectors and replicating oncolytic viruses have been developed for brain cancer treatment, and the mechanistic background of their cytotoxicity has been unveiled. A growing number of clinical trials have convincingly established viral therapies to be safe in glioma patients, and maximum tolerated doses have generally not been reached. However, evidence for therapeutic benefit has been limited: new generations of therapeutic vectors need to be developed in order to target not only tumor cells but also the complex surrounding microenvironment. Such therapies could also direct long-lasting immune responses toward the tumor while reducing early antiviral reactions. Furthermore, viral delivery methods are to be improved and viral spread within the tumor will have to be enhanced. Here, we will review the outcome of completed glioma virus therapy trials as well as highlight the ongoing clinical activities. On this basis, we will give an overview of the numerous strategies to enhance therapeutic efficacy of new-generation viruses and novel treatment regimens. Finally, we will conclude with approaches that may be crucial to the development of successful glioma therapies in the future.