Primary gliosarcoma: key clinical and pathologic distinctions from glioblastoma with implications as a unique oncologic entity

Exploring ncRNA-mediated regulation of EGFR signalling in glioblastoma: From mechanisms to therapeutics

Glioblastoma (GBM) is the most prevalent and deadly primary brain tumor type, with a discouragingly low survival rate and few effective treatments. An important function of the EGFR signalling pathway in the development of GBM is to affect tumor proliferation, persistence, and treatment resistance. Advances in molecular biology in the last several years have shown how important ncRNAs are for controlling a wide range of biological activities, including cancer progression and development. NcRNAs have become important post-transcriptional regulators of gene expression, and they may affect the EGFR pathway by either directly targeting EGFR or by modifying important transcription factors and downstream signalling molecules. The EGFR pathway is aberrantly activated in response to the dysregulation of certain ncRNAs, which has been linked to GBM carcinogenesis, treatment resistance, and unfavourable patient outcomes. We review the literature on miRNAs, circRNAs and lncRNAs that are implicated in the regulation of EGFR signalling in GBM, discussing their mechanisms of action, interactions with the signalling pathway, and implications for GBM therapy. Furthermore, we explore the potential of ncRNA-based strategies to overcome resistance to EGFR-targeted therapies, including the use of ncRNA mimics or inhibitors to modulate the activity of key regulators within the pathway.

Primary and secondary gliosarcoma: differences in treatment and outcome

INTRODUCTION

There are only few studies comparing differences in the outcome of primary versus secondary gliosarcoma. This study aimed to review the outcome and survival of patients with primary or secondary gliosarcoma following surgical resection and adjuvant treatment. The data were also matched with data of patients with primary and secondary glioblastoma (GBM).

PATIENTS AND METHODS

Treatment histories of 10 patients with primary gliosarcoma and 10 patients with secondary gliosarcoma were analysed and compared. Additionally, data of 20 patients with primary and 20 patients with secondary GBM were analysed and compared. All patients underwent surgical resection of the tumour in our department. Follow-up data, progression-free survival (PFS), and median overall survival (mOS) were evaluated.

RESULTS

The median PFS in patients with primary gliosarcoma was significantly higher than in patients with secondary gliosarcoma (p = 0.037). The 6-month PFS rates were 80.0% in patients with primary and 30.0% in patients with secondary gliosarcoma. Upon recurrence, five patients with primary gliosarcoma and four patients with secondary gliosarcoma underwent repeat surgical resection. The mOS of patients with primary gliosarcoma was significantly higher than that of patients with secondary gliosarcoma (p = 0.031). The percentage of patients surviving at 1-year/2-year follow-up in primary gliosarcoma was 70%/20%, while it was only 10%/10% in secondary gliosarcoma. When PFS and mOS of primary gliosarcoma was compared to primary GBM, there were no statistically differences (p = 0.509; p = 0.435). The PFS and mOS of secondary gliosarcoma and secondary GBM were also comparable (p = 0.290 and p = 0.390).

CONCLUSION

Patients with primary gliosarcoma have a higher PFS and mOS compared to those with secondary gliosarcoma. In the case of tumour recurrence, patients with secondary gliosarcoma harbour an unfavourable prognosis with limited further options. The outcome of patients with primary or secondary gliosarcoma is comparable to that of patients with primary or secondary GBM.

Molecular signature of stem-like glioma cells (SLGCs) from human glioblastoma and gliosarcoma

Glioblastoma multiforme (GBM) and the GBM variant gliosarcoma (GS) are among the tumors with the highest morbidity and mortality, providing only palliation. Stem-like glioma cells (SLGCs) are involved in tumor initiation, progression, therapy resistance, and relapse. The identification of general features of SLGCs could contribute to the development of more efficient therapies. Commercially available protein arrays were used to determine the cell surface signature of eight SLGC lines from GBMs, one SLGC line obtained from a xenotransplanted GBM-derived SLGC line, and three SLGC lines from GSs. By means of non-negative matrix factorization expression metaprofiles were calculated. Using the cophenetic correlation coefficient (CCC) five metaprofiles (MPs) were identified, which are characterized by specific combinations of 7-12 factors. Furthermore, the expression of several factors, that are associated with GBM prognosis, GBM subtypes, SLGC differentiation stages, or neural identity was evaluated. The investigation encompassed 24 distinct SLGC lines, four of which were derived from xenotransplanted SLGCs, and included the SLGC lines characterized by the metaprofiles. It turned out that all SLGC lines expressed the epidermal growth factor EGFR and EGFR ligands, often in the presence of additional receptor tyrosine kinases. Moreover, all SLGC lines displayed a neural signature and the IDH1 wildtype, but differed in their p53 and PTEN status. Pearson Correlation analysis identified a positive association between the pluripotency factor Sox2 and the expression of FABP7, Musashi, CD133, GFAP, but not with MGMT or Hif1α. Spherical growth, however, was positively correlated with high levels of Hif1α, CDK4, PTEN, and PDGFRβ, whereas correlations with stemness factors or MGMT (MGMT expression and promoter methylation) were low or missing. Factors highly expressed by all SLGC lines, irrespective of their degree of stemness and growth behavior, are Cathepsin-D, CD99, EMMPRIN/CD147, Intβ1, the Galectins 3 and 3b, and N-Cadherin.

TGF-β and BMP signaling are associated with the transformation of glioblastoma to gliosarcoma and then osteosarcoma

Background

Gliosarcoma, an isocitrate dehydrogenase wildtype (IDH-WT) variant of glioblastoma, is defined by clonal biphasic differentiation into gliomatous and sarcomatous components. While the transformation from a glioblastoma to gliosarcoma is uncommon, the subsequent transformation to osteosarcoma is rare but may provide additional insights into the biology of these typically distinct cancers. We observed a patient initially diagnosed with glioblastoma, that differentiated into gliosarcoma at recurrence, and further evolved to osteosarcoma at the second relapse. Our objective was to characterize the molecular mechanisms of tumor progression associated with this phenotypic transformation.

Methods

Tumor samples were collected at all 3 stages of disease and RNA sequencing was performed to capture their transcriptomic profiles. Sequential clonal evolution was confirmed by the maintenance of an identical PTEN mutation throughout the tumor differentiation using the TSO500 gene panel. Publicly available datasets and the Nanostring nCounter technology were used to validate the results.

Results

The glioblastoma tumor from this patient possessed mixed features of all 3 TCGA-defined transcriptomic subtypes of an IDH-WT glioblastoma and a proportion of osteosarcoma signatures were upregulated in the original tumor. Analysis showed that enhanced transforming growth factor-β (TGF-β) and bone morphogenic protein signaling was associated with tumor transformation. Regulatory network analysis revealed that TGF-β family signaling committed the lineage tumor to osteogenesis by stimulating the expression of runt-related transcription factor 2 (RUNX2), a master regulator of bone formation.

Conclusions

This unusual clinical case provided an opportunity to explore the modulators of longitudinal sarcomatous transformation, potentially uncovering markers indicating predisposition to this change and identification of novel therapeutic targets.

Primary Intracranial Gliosarcoma: Is It Really a Variant of Glioblastoma? An Update of the Clinical, Radiological, and Biomolecular Characteristics

Gliosarcomas (GS) are sporadic malignant tumors classified as a Glioblastoma (GBM) variant with IDH-wild type phenotype. It appears as a well-circumscribed lesion with a biphasic, glial, and metaplastic mesenchymal component. The current knowledge about GS comes from the limited literature. Furthermore, recent studies describe peculiar characteristics of GS, such as hypothesizing that it could be a clinical-pathological entity different from GBM. Here, we review radiological, biomolecular, and clinical data to describe the peculiar characteristics of PGS, treatment options, and outcomes in light of the most recent literature. A comprehensive literature review of PubMed and Web of Science databases was conducted for articles written in English focused on gliosarcoma until 2023. We include relevant data from a few case series and only a single meta-analysis. Recent evidence describes peculiar characteristics of PGS, suggesting that it might be a specific clinical-pathological entity different from GBM. This review facilitates our understanding of this rare malignant brain tumor. However, in the future we recommend multi-center studies and large-scale metanalyses to clarify the biomolecular pathways of PGS to develop new specific therapeutic protocols, different from conventional GBM therapy in light of the new therapeutic opportunities.

RAR-Dependent and RAR-Independent RXR Signaling in Stem-like Glioma Cells

Retinoic acid (RA) exerts pleiotropic effects during neural development and regulates homeostasis in the adult human brain. The RA signal may be transduced through RXR (retinoid-X receptor)-non-permissive RA receptor/RXR heterodimers or through RXR-permissive RXR heterodimers. The significance of RA signaling in malignant brain tumors such as glioblastoma multiforme (GBM) and gliosarcoma (GS) is poorly understood. In particular, the impact RA has on the proliferation, survival, differentiation, or metabolism of GBM- or GS-derived cells with features of stem cells (SLGCs) remains elusive. In the present manuscript, six GBM- and two GS-derived SLGC lines were analyzed for their responsiveness to RAR- and RXR-selective agonists. Inhibition of proliferation and initiation of differentiation were achieved with a RAR-selective pan-agonist in a subgroup of SLGC lines, whereas RXR-selective pan-agonists (rexinoids) supported proliferation in most SLGC lines. To decipher the RAR-dependent and RAR-independent effects of RXR, the genes encoding the RAR or RXR isotypes were functionally inactivated by CRISPR/Cas9-mediated editing in an IDH1-/p53-positive SLGC line with good responsiveness to RA. Stemness, differentiation capacity, and growth behavior were preserved after editing. Taken together, this manuscript provides evidence about the positive impact of RAR-independent RXR signaling on proliferation, survival, and tumor metabolism in SLGCs.

A Rare Tumor in a Rare Location: Radiology and Pathology Findings With a Literature Review on Intraventricular Gliosarcoma

Gliosarcoma (GS) is an extraordinarily rare variant of glioblastoma, which is differentiated by its distinct biphasic histopathological morphology consisting of both glial and mesenchymal elements. Although GS has a predilection for the cortical hemispheres, rare occurrences of intraventricular gliosarcoma (IVGS) have been documented in the literature. In this report, we present a 68-year-old female patient with a primary IVGS arising from the frontal horn of the left ventricle with corresponding left ventricular entrapment. The clinical course as well as associated tumor features as observed on computed tomography (CT), magnetic resonance imaging (MRI), and immunohistochemical studies are presented along with a relevant review of the current literature.

Prognostic Factors of Gliosarcoma in the Real World: A Retrospective Cohort Study

Purpose

Gliosarcoma is a histopathological variant of glioblastoma, which is characterized by a biphasic growth pattern consisting of glial and sarcoma components. Owing to its scarcity, data regarding the impact of available treatments on the clinical outcomes of gliosarcoma are inadequate. The purpose of this retrospective cohort study was to analyze the prognostic factors of gliosarcoma.

Methods

By screening the clinical database of neurosurgical cases at a single center, patients with gliosarcoma diagnosed histologically from 2013 to 2021 were identified. Clinical, pathological, and molecular data were gathered founded on medical records and follow-up interviews. Prognostic factors were derived using the Cox proportional hazards model with backward stepwise regression analysis.

Results

Forty-five GSM patients were included. Median overall survival was 25.6 months (95% CI 8.0-43.1), and median relapse-free survival was 15.2 months (95% CI 9.7-20.8). In multivariable analysis, total resection (p = 0.023, HR = 0.192, 95% CI 0.046-0.797) indicated an improved prognosis. And low expression of Ki-67 (p = 0.059, HR = 2.803, 95% CI 0.963-8.162) would be likely to show statistical significance. However, there might be no statistically significant survival benefit from radiotherapy with concurrent temozolomide (n = 33, 73.3%, log-rank p = 0.99) or adjuvant temozolomide (n = 32, 71.1%, log-rank p = 0.74).

Conclusion

This single-center retrospective study with a limited cohort size has demonstrated the treatment of gross total resection and low expression of Ki-67 which are beneficial for patients with GSM, while radiotherapy or temozolomide is not.

Primary gliosarcoma with widespread extracranial metastases—spatiotemporal morphological variation

Background

We summarize 5 cases of primary gliosarcoma with widespread extracranial metastases including our case. The glial components are eliminated due to the needs of the living environment in the process of parasitism and survival of brain glioma-sarcoma cells in lung metastasis.

Methods

A PubMed search using the keywords “gliosarcoma” and “extracranial metastases” was performed followed by a review of cited literature. Our case was a 50-year-old female presented with headache and dizziness. MRI examination showed that there was a cystic solid tumor in the right temporal lobe. The tumor was removed totally. Seven months after the operation, the patient suffered recurrent intermittent headache. The resection for the recurrent tumor was performed. Postoperative pathology confirmed the recurrent gliosarcoma. A needle biopsy was performed for the nodular on the right lung. The lung tumor pathology suggested a sarcoma structure.

Results

There was a female patient in five cases. The age range is 47 to 69 years old. The tumor recurred within a year. A combination of treatment modalities may extend survival; however, the prognosis remains poor.

Conclusion

Primary gliosarcoma with extracranial metastases is extremely rare. Some findings uncovered an unexpected spatiotemporal morphological variation in the different foci of the same malignancy.

Multidisciplinary approaches to gliosarcoma: A case report and review of the literature

A 58-year-old right-handed man presented to our tertiary care center with gliosarcoma (GS) infiltration through the dura, skull, and soft tissue. Patient had a previous history of right temporal GS, with four intracranial surgeries prior to presentation. A multidisciplinary approach was used to treat the lesion and perform reconstruction.

Gliosarcoma: The Distinct Genomic Alterations Identified by Comprehensive Analysis of Copy Number Variations

Gliosarcoma (GSM), a histologic variant of glioblastoma (GBM), carries a poor prognosis with less than one year of median survival. Though GSM is similar with GBM in most clinical and pathological symptoms, GBM has unique molecular and histological features. However, as the rarity of GSM samples, the genetic information of this tumor is still lacking. Here, we take a comprehensive analysis of DNA copy number variations (CNV) in GBM and GSM. Whole genome sequencing was performed on 21 cases of GBM and 15 cases of GSM. CNVKIT is used for CNV calling. Our data showed that chromosomes 7, 8, 9, and 10 were the regions where CNV frequently happened in both GBM and GSM. There was a distinct CNV signal in chromosome 2 especially in GSM. The pathway enrichment of genes with CNV was suggested that the GBM and GSM shared the similar mechanism of tumor development. However, the CNV of some screened genes displayed a disparate form between GBM and GSM, such as AMP, BEND2, HDAC6, FOXP3, ZBTB33, TFE3, and VEGFD. It meant that GSM was a distinct subgroup possessing typical biomarkers. The pathways and copy number alterations detected in this study may represent key drivers in gliosarcoma oncogenesis and may provide a starting point toward targeted oncologic analysis with therapeutic potential.

Survival outcomes associated with MGMT promoter methylation and temozolomide in gliosarcoma patients

PURPOSE

Gliosarcoma is an uncommon glioblastoma subtype, for which MGMT promoter methylation's relationship with response to temozolomide chemotherapy is unclear. We therefore examined this question using a national cohort.

METHODS

 The National Cancer Database was queried for patients histopathologically diagnosed with gliosarcoma between 2010 and 2019. The associations between MGMT promoter methylation, first-line single-agent chemotherapy-presumed to be temozolomide herein-and overall survival (OS) were examined using log-rank tests and Cox regression, with correction for multiple testing (p < 0.01 was significant).

RESULTS

580 newly-diagnosed gliosarcoma patients with MGMT status were available, among whom 33.6% were MGMT promoter methylated. Median OS for gliosarcoma patients that received standard-of-care temozolomide and radiotherapy was 12.1 months (99% confidence interval [CI] 10.8-15.1) for MGMT promoter unmethylated and 21.4 months (99% CI 15.4-26.2) for MGMT promoter methylated gliosarcomas (p = 0.003). In multivariable analysis of gliosarcoma patients-which included the potential confounders of age, sex, maximal tumor size, extent of resection, and radiotherapy-receipt of temozolomide was associated with improved OS in both MGMT promoter methylated (hazard ratio [HR] 0.23 vs. no temozolomide, 99% CI 0.11-0.47, p < 0.001) and unmethylated (HR 0.50 vs. no temozolomide, 99% CI 0.29-0.89, p = 0.002) gliosarcomas. MGMT promoter methylation was associated with improved OS among temozolomide-treated gliosarcoma patients (p < 0.001), but not in patients who did not receive chemotherapy (p = 0.35).

CONCLUSION

In a national analysis of gliosarcoma patients, temozolomide was associated with prolonged OS irrespective of MGMT status. These results provide support for the current practice of trimodal therapy for gliosarcoma.

Gliosarcoma with direct involvement of the oculomotor nerve: Case report and literature review

Gliosarcoma is a rare malignant brain tumor, characterized by a biphasic tissue pattern with alternating areas displaying glial and mesenchymal differentiation. We first report a case of temporo-mesial gliosarcoma, extended to the crural and ambient cisterns, with direct involvement of the ipsilateral third cranial nerve and encasement of anterior choroidal, posterior communicant and posterior cerebral arteries, presenting without symptoms of peripheral neuropathy. A 61-year-old woman with 1-month history of intense bilateral frontal-temporal headache resistant to pharmacological therapy and paresis of the left lower midface underwent surgical resection, through pterional trans-sylvian approach, of a right temporo-mesial gliosarcoma which directly involved the ipsilateral oculomotor nerve. Reported cases of gliomas with direct involvement of a cranial nerve, from the third to the twelfth, are very rare, whit no cases of gliosarcoma described. Because of its rarity, sometimes this entity is not considered as diagnostic hypothesis and is misdiagnosed, both during preoperative diagnostic evaluation and during the surgery. Gliosarcoma is a strong challenge for neurosurgeons and neurooncologists because of low incidence, poor prognosis and limited reported cases on literature. This case shows unique features for localization, pattern of growth and clinical presentation.

Primary intraventricular gliosarcoma on MRI: A challenging diagnosis

Gliosarcoma (GS) is an uncommon central nervous system tumor with several characteristics of a malignant neoplasm and poor prognosis. The majority of GS reports describe a predilection for the cerebral hemispheres, and cases of intraventricular GS are extremely rare, with only a few reported. In addition, intraventricular GS has not been associated with any unique radiographic or clinical features, which can result in misdiagnosis as other intraventricular tumor types. In this report, we present the case of a 32-year-old woman with GS in the trigone of the lateral ventricle and provide a retrospective review of similar, previously reported cases.

Sarcomatous Change of Cerebellopontine Angle Ependymoma Following Radiosurgery: A Case Report

Sarcomatous change in ependymal tumors is rare and has been poorly described. We report on a cerebellopontine angle lesion that demonstrated rapid progression two years after radiosurgery in a 73-year-old female patient. Histopathological diagnosis at clinical progression showed an ependymoma with sarcomatous change (“ependymosarcoma”) that was believed to be due to radiation. The patient underwent a complex tumor resection without complications using an exhaustive multi-modal neuromonitoring paradigm throughout the dissection and resection of the tumor. Given the limited available data on these rare tumors, we review their presentation, imaging, and histopathology in the context of the previous literature, and also discuss the management of these lesions in the cerebellopontine angle.

Chasing a rarity: a retrospective single-center evaluation of prognostic factors in primary gliosarcoma

Background and purpose

Primary gliosarcoma (GS) is a rare variant of IDH-wildtype glioblastoma multiforme. We performed a single-center analysis to identify prognostic factors.

Patients and methods

We analyzed the records of 26 patients newly diagnosed with primary WHO grade IV GS. Factors of interest were clinical and treatment data, as well as molecular markers, time to recurrence, and time to death.

Results

Median follow-up was 9 months (range 5–21 months). Gross total resection did not lead to improved survival, most likely due to the relatively small sample size. Low symptom burden at the time of diagnosis was associated with longer PFS (P = 0.023) and OS (P = 0.018). Median OS in the entire cohort was 12 months. Neither MGMT promoter hypermethylation nor adjuvant temozolomide therapy influenced survival, consistent with some previous reports.

Conclusion

In this retrospective study, patients exhibiting low symptom burden at diagnosis showed improved survival. None of the other factors analyzed were associated with an altered outcome.

Epidemiologic Features, Survival, and Prognostic Factors Among Patients With Different Histologic Variants of Glioblastoma: Analysis of a Nationwide Database

Background: Glioblastoma (GBM) is the most common primary intracranial malignancy. Previous studies found incidence of GBM varies substantially by age, sex, race and ethnicity, and survival also varies by country, ethnicity, and treatment. Gliosarcoma (GSM) and giant cell glioblastoma (GC-GBM) are different histologic variants of GBM with distinct clinico-pathologic entities. We conducted a study to compare epidemiology, survival, and prognostic factors among the three.

Methods: We identified GBM patients diagnosed between 2000 and 2016 using the Taiwan Cancer Registry and followed them using the death registry. Survival was compared among conventional GBM and two histologic variants. The potential confounding factors evaluated in this study included registered year, age, sex, and treatment modality (resection, radiotherapy, and chemotherapy).

Results: We enrolled 3,895 patients, including 3,732 (95.8%) with conventional GBM, 102 (2.6%) with GSM, and 61 (1.6%) with GC-GBM. GC-GBM patients had younger mean age at diagnosis (49.5 years) than conventional GBM patients (58.7 years) and GSM patients (61.3 years) (p < 0.01). The three groups had similar sex distributions (p = 0.29). GC-GBM had a longer median survival [18.5, 95% confidence interval (CI): 15.8–25.3 months] than conventional GBM (12.5, 95%CI: 12.0–13.0 months) and GSM (12.8, 95%CI: 9.2–16.2 months), and the differences in overall survival did not attain statistical significance (p = 0.08, log-rank test). In univariate analysis, GC-GBM had better survival than conventional GBM, but the hazard ratio (0.91) did not reach statistical significance (95%CI: 0.69–1.20) in the multivariate analysis. Young ages (≤ 40 years), female sex, resection, radiotherapy, and chemotherapy were factors associated with better survival in overall GBMs. In subtype analyses, these factors remained statistically significant for conventional GBM, as well as radiotherapy for GSM.

Conclusion: Our analysis found conventional GBM and its variants shared similar poor survival. Factors with age ≤ 40 years, female sex, resection, radiotherapy, and chemotherapy were associated with better prognosis in conventional GBM patients.

Genetic alteration and clonal evolution of primary glioblastoma into secondary gliosarcoma

Aims

Secondary gliosarcoma (SGS) rarely arises post treatment of primary glioblastoma multiforme (GBM), and contains gliomatous and sarcomatous components. The origin and clonal evolution of SGS sarcomatous components remain uncharacterized. Therapeutic radiation is mutagenic and can induce sarcomas in patients with other tumor phenotypes, but possible causal relationships between radiotherapy and induction of SGS sarcomatous components remain unexplored. Herein, we investigated the clonal origin of SGS in a patient with primary GBM progressing into SGS post‐radiochemotherapy.

Methods

Somatic mutation profile in GBM and SGS was examined using whole‐genome sequencing and deep‐whole‐exome sequencing. Mutation signatures were characterized to investigate relationships between radiochemotherapy and SGS pathogenesis.

Results

A mutation cluster containing two founding mutations in tumor‐suppressor genes NF1 (variant allele frequency [VAF]: 50.0% in GBM and 51.1% in SGS) and TP53 (VAF: 26.7% in GBM and 50.8% in SGS) was shared in GBM and SGS. SGS exhibited an overpresented C>A (G>T) transversion (oxidative DNA damage signature) but no signature 11 mutations (alkylating‐agents – exposure signature). Since radiation induces DNA lesions by generating reactive oxygen species, the mutations observed in this case of SGS were likely the result of radiotherapy rather than chemotherapy.

Conclusions

Secondary gliosarcoma components likely have a monoclonal origin, and the clone possessing mutations in NF1 and TP53 was likely the founding clone in this case of SGS.

Genomic landscape of gliosarcoma: distinguishing features and targetable alterations

Gliosarcoma is an aggressive brain tumor with histologic features of glioblastoma (GBM) and soft tissue sarcoma. Despite its poor prognosis, its rarity has precluded analysis of its underlying biology. We used a multi-center database to characterize the genomic landscape of gliosarcoma. Sequencing data was obtained from 35 gliosarcoma patients from Genomics Evidence Neoplasia Information Exchange (GENIE) 5.0, a database curated by the American Association of Cancer Research (AACR). We analyzed genomic alterations in gliosarcomas and compared them to GBM (n = 1,449) and soft tissue sarcoma (n = 1,042). 30 samples were included (37% female, median age 59 [IQR: 49–64]). Nineteen common genes were identified in gliosarcoma, defined as those altered in > 5% of samples, including TERT Promoter (92%), PTEN (66%), and TP53 (60%). Of the 19 common genes in gliosarcoma, 6 were also common in both GBM and soft tissue sarcoma, 4 in GBM alone, 0 in soft tissue sarcoma alone, and 9 were more distinct to gliosarcoma. Of these, BRAF harbored an OncoKB level 1 designation, indicating its status as a predictive biomarker of response to an FDA-approved drug in certain cancers. EGFR, CDKN2A, NF1, and PTEN harbored level 4 designations in solid tumors, indicating biological evidence of these biomarkers predicting a drug-response. Gliosarcoma contains molecular features that overlap GBM and soft tissue sarcoma, as well as its own distinct genomic signatures. This may play a role in disease classification and inclusion criteria for clinical trials. Gliosarcoma mutations with potential therapeutic indications include BRAF, EGFR, CDKN2A, NF1, and PTEN.

Machine Learning-Based Analysis of Magnetic Resonance Radiomics for the Classification of Gliosarcoma and Glioblastoma

Objective

To identify optimal machine-learning methods for the radiomics-based differentiation of gliosarcoma (GSM) from glioblastoma (GBM).

Materials and Methods

This retrospective study analyzed cerebral magnetic resonance imaging (MRI) data of 83 patients with pathologically diagnosed GSM (58 men, 25 women; mean age, 50.5 ± 12.9 years; range, 16-77 years) and 100 patients with GBM (58 men, 42 women; mean age, 53.4 ± 14.1 years; range, 12-77 years) and divided them into a training and validation set randomly. Radiomics features were extracted from the tumor mass and peritumoral edema. Three feature selection and classification methods were evaluated in terms of their performance in distinguishing GSM and GBM: the least absolute shrinkage and selection operator (LASSO), Relief, and Random Forest (RF); and adaboost classifier (Ada), support vector machine (SVM), and RF; respectively. The area under the receiver operating characteristic curve (AUC) and accuracy (ACC) of each method were analyzed.

Results

Based on tumor mass features, the selection method LASSO + classifier SVM was found to feature the highest AUC (0.85) and ACC (0.77) in the validation set, followed by Relief + RF (AUC = 0.84, ACC = 0.72) and LASSO + RF (AUC = 0.82, ACC = 0.75). Based on peritumoral edema features, Relief + SVM was found to have the highest AUC (0.78) and ACC (0.73) in the validation set. Regardless of the method, tumor mass features significantly outperformed peritumoral edema features in the differentiation of GSM from GBM (P < 0.05). Furthermore, the sensitivity, specificity, and accuracy of the best radiomics model were superior to those obtained by the neuroradiologists.

Conclusion

Our radiomics study identified the selection method LASSO combined with the classifier SVM as the optimal method for differentiating GSM from GBM based on tumor mass features.

Gliosarcoma vs. glioblastoma: a retrospective case series using molecular profiling

Background

Gliosarcoma (GS) refers to the presence of mesenchymal differentiation (as seen using light microscopy) in the setting of glioblastoma (GB, an astrocytoma, WHO Grade 4). Although the same approach to treatment is typically adopted for GS and GB, there remains some debate as to whether GS should be considered a discrete pathological entity. Differences between these tumors have not been clearly established at the molecular level.

Methods

Patients with GS (n=48) or GB (n=1229) underwent molecular profiling (MP) with a pan-cancer panel of tests as part of their clinical care. The methods employed included next-generation sequencing (NGS) of DNA and RNA, copy number variation (CNV) of DNA and immunohistochemistry (IHC). The MP comprised 1153 tests in total, although results for each test were not available for every tumor profiled. We analyzed this data retrospectively in order to determine if our results were in keeping with what is known about the pathogenesis of GS by contrast with GB. We also sought novel associations between the MP and GS vs. GB which might improve our understanding of pathogenesis of GS.

Results

Potentially meaningful associations (p<0.1, Fisher’s exact test (FET)) were found for 14 of these tests in GS vs. GB. A novel finding was higher levels of proteins mediating immuno-evasion (PD-1, PD-L1) in GS. All of the differences we observed have been associated with epithelial-to-mesenchymal transition (EMT) in other tumor types. Many of the changes we saw in GS are novel in the setting of glial tumors, including copy number amplification in LYL1 and mutations in PTPN11.

Conclusions

GS shows certain characteristics of EMT, by contrast with GB. Treatments targeting immuno-evasion may be of greater therapeutic value in GS relative to GB.

Supplementary Information

The online version contains supplementary material available at (10.1186/s12883-021-02233-5).

IDH1-mutant primary intraventricular gliosarcoma: Case report and systematic review of a rare location and molecular profile

Background:

Gliosarcoma (GS) is classified as an IDH-wild-type variant of glioblastoma (GBM). While GS is already an unusual presentation of GBM, IDH1-mutant cases are especially rare. We present an IDH1-mutant primary intraventricular GS case report and a systematic review of the molecular profile in GS correlating to the prognostic and pathogenesis of IDH1/2 mutations.

Case Description:

A 44-years-old man presented with ongoing fatigue symptoms and a new-onset intense occipital headache. The patient complained of memory loss, dyscalculia, and concentration difficulties. An MRI revealed a bihemispheric intraventricular mass crossing the midline through the corpus callosum and infiltrating the trigone of the lateral ventricles, hypointense, and hyperintense on the T1- and T2-weighted image. We performed a microsurgical resection with a transparietal transsulcal approach; however, the contralateral mass was attached to vascular structures and we decided to reoperate the patient in another moment. The histopathological study showed a Grade IV tumor and the immunohistochemistry confirmed the diagnosis of GS. The patient presented progressive neurologic decline and died 45 days after the surgical approach.

Conclusion:

We did two systematic reviews studies from PubMed, EMBASE, MEDLINE, Cochrane, and SCOPUS databases, and included molecular and intraventricular studies of GS. We performed further meta-analysis using OpenMetaAnalyst™ software. We conducted a forest plot with the molecular profile of GS. When correlated IDH1 mutation versus tp53 mutation, we found an odds ratio (OR) of 0.018 (0.005–0.064) and P < 0.001. Moreover, we compared IDH1 mutation versus MGMT methylation (P = 0.006; OR = 0.138 [0.034–0.562]). The studies evaluating the molecular profile in GS prognostics are often extended from all GBMs despite specifics GBM variants (i.e., GS). We found a correlation between IDH1 mutation expression with tp53 and MGMT expression in GS, and future studies exploring this molecular profile in GS are strongly encouraged.

Gliosarcoma with Adenoid and Chondrosarcomatous Differentiation: A Case Report

A heterogeneous group of CNS tumors are characterized by mixed neuroepithelial and mesenchymal features. Glial tumors manifesting this phenomenon are referred to as gliosarcoma. These tumors are usually mistaken for cerebral metastases or meningioma at operation. Their histological studies have revealed an admixture of gliomatous and sarcomatous tissues, which leads to a biphasic pattern. The mesenchymal component can present in different forms such as fibrosarcoma, undifferentiated pleomorphic sarcoma, chondro-osteogenic, and myogenic differentiation, as well as angiosarcomatous and liposarcomatous types. Squamous differentiation, adenoid formations and glandular structures may also be displayed. Herein, we report a rare case who was admitted to the emergency room with decreased consciousness resembling methadone poisoning. Clinical work-up showed a temporoparietal mass on radiological investigation. Histopathological evaluation of the brain mass revealed a gliosarcoma with adenoid formations and a mesenchymal component, which manifested as chondrosarcomatous differentiation. Immunohistochemical studies confirmed the histologic diagnosis through positivity for EMA, GFAP, S100, and vimentin expression in different components.

Extensive subdural spread of a glioblastoma associated with subdural hygroma: case report

Despite its highly malignant behaviour, glioblastoma very rarely spread beside the arachnoid layer. We describe a very rare case of a 67-year-old patient with glioblastoma, who developed a recurrent subdural hygroma associated with the subdural spread of the glioblastoma, which was confirmed histologically. Possible predisposing factors and management suggestions are discussed.

Primary pediatric cerebellar gliosarcoma

Background:

Primary gliosarcomas of the central nervous are rare and very few have been reported in the infratentorial compartment. Here, we describe such a lesion in a 12-year-old male.

Case Description:

A 12-year-old male presented with headache, ataxia, and vomiting. When Magnetic resonance studies documented a posterior fossa lesion, he underwent placement of a right ventriculoperitoneal shunt followed by a suboccipital craniectomy. The lesion proved to be a primary gliosarcoma. Unfortunately, it recurred 2 years later and required repeated resection.

Conclusion:

Here, we reviewed the rare case of a 12-year-old male requiring shunt placement and suboccipital craniectomy for a primary gliosarcoma that recurred 2 years later.

Dendrimer size effects on the selective brain tumor targeting in orthotopic tumor models upon systemic administration

Malignant gliomas are the most common and aggressive form of primary brain tumors, with a median survival of 15-20 months for patients receiving maximal interventions. Advances in nanomedicine have provided tumor-specific delivery of chemotherapeutics to potentially overcome their off-target toxicities. Recent advances in dendrimer-based nanomedicines have established that hydroxyl-terminated poly(amidoamine) dendrimers can intrinsically target neuroinflammation and brain tumors from systemic administration without the need for targeting moieties. The size of nanocarriers is a critical parameter that determines their tumor-targeting efficiency, intratumor distribution, and clearance mechanism. In this study, we explore the dendrimer size effects on brain tumor targeting capability in two clinically relevant orthotopic brain tumor models, the 9L rat and GL261 mouse models, which capture differing aspects of gliomas. We show that increasing dendrimers from Generation 4 to Generation 6 significantly enhances their tumor accumulation (~10-fold greater at 24 hr), tumor specificity (~2-3 fold higher), and tumor retention. The superior tumor targeting effect of G6 dendrimers is associated with its reduced renal clearance rate, resulting in longer circulation time compared to G4 dendrimers. Additionally, the increase in dendrimer generation does not compromise its homogeneous tumor distribution and intrinsic targeting of tumor-associated macrophages. These results validate the potential for these dendrimers as an effective, clinically translatable platform for effectively targeting tumor-associated macrophages in malignant gliomas.

The clinical, radiological, and immunohistochemical characteristics and outcomes of primary intracranial gliosarcoma: a retrospective single-centre study

Primary intracranial gliosarcoma is a rare malignant brain tumour, and the most effective treatment for gliosarcoma remains unclear. This study aimed to identify risk factors for progression-free survival (PFS) and overall survival (OS) in these cases. This retrospective single-centre study evaluated 103 patients (median age, 51 years; 67 men [65%]) with primary intracranial gliosarcoma between 2006 and 2017. Treatments included surgery (GTR, 63 patients; STR, 39 patients; biopsy, 1 patient), radiotherapy (adjuvant, 76 patients; exclusive treatment, 1 patient), and chemotherapy (adjuvant temozolomide, 52 patients; adjuvant nimustine/teniposide, 19 patients; adjuvant bevacizumab, 1 patient; exclusive nimustine/teniposide treatment, 1 patient). The median OS was 13.3 months, and the median PFS was 9.1 months. In the multivariate analyses, the poor prognostic factors were ependymal lining enhancement of the lateral ventricle (PFS, HR 2.406, p = 0.005; OS, HR 2.946, p = 0.009) and enhancement in the motor functional cortex (PFS, HR 2.892, p = 0.002; OS, HR 2.639, p = 0.009). Good OS was predicted by adjuvant radiotherapy alone (HR 0.071, p < 0.001), adjuvant temozolomide-based chemotherapy alone (HR 0.063, p = 0.005), adjuvant temozolomide-based chemotherapy with concurrent radiotherapy (HR 0.056, p < 0.001), and salvage surgery at recurrence (HR 0.449, p = 0.031). The present study revealed that, in patients with primary intracranial gliosarcoma, enhancement in the functional motor cortex and ependymal lining enhancement of the lateral ventricle were both poor prognostic factors. Survival was optimized in cases treated using maximal safe resection followed by adjuvant temozolomide-based chemotherapy with concurrent radiotherapy. Furthermore, salvage surgery provided meaningful therapeutic benefits for recurrent gliosarcoma.

Evaluating Surgical Resection Extent and Adjuvant Therapy in the Management of Gliosarcoma

Introduction: Gliosarcomas are clinically aggressive tumors, histologically distinct from glioblastoma. Data regarding the impact of extent of resection and post-operative adjuvant therapy on gliosarcoma outcomes are limited.

Methods: Patients with histologically confirmed gliosarcoma diagnosed between 1999 and 2019 were identified. Clinical, molecular, and radiographic data were assembled based on historical records. Comparisons of categorical variables used Pearson's Chi-square and Fisher's exact test while continuous values were compared using the Wilcoxon signed-rank test. Survival comparisons were assessed using Kaplan-Meier statistics and Cox regressions.

Results: Seventy-one gliosarcoma patients were identified. Secondary gliosarcoma was not associated with worse survival when compared to recurrent primary gliosarcoma (median survival 9.8 [3.8 to 21.0] months vs. 7.6 [1.0 to 35.7], p = 0.7493). On multivariable analysis, receipt of temozolomide (HR = 0.02, 95% CI 0.001–0.21) and achievement of gross total resection (GTR; HR = 0.13, 95% CI 0.02–0.77) were independently prognostic for improved progression-free survival (PFS) while only receipt of temozolomide was independently associated with extended overall survival (OS) (HR = 0.03, 95% CI 0.001–0.89). In patients receiving surgical resection followed by radiotherapy and concomitant temozolomide, achievement of GTR was significantly associated with improved PFS (median 32.97 [7.1–79.6] months vs. 5.45 [1.8–26.3], p = 0.0092) and OS (median 56.73 months [7.8–104.5] vs. 14.83 [3.8 to 29.1], p = 0.0252).

Conclusion: Multimodal therapy is associated with improved survival in gliosarcoma. Even in patients receiving aggressive post-operative multimodal management, total surgical removal of macroscopic disease remains important for optimal outcomes.

Molecular and clonal evolution in recurrent metastatic gliosarcoma

We discuss the molecular evolution of gliosarcoma, a mesenchymal type of glioblastoma (GBM), using the case of a 37-yr-old woman who developed two recurrences and an extracranial metastasis. She was initially diagnosed with isocitrate dehydrogenase (IDH) wild-type gliosarcoma in the frontal lobe and treated with surgery followed by concurrent radiotherapy with temozolomide. Five months later the tumor recurred in the left frontal lobe, outside the initially resected area, and was treated with further surgery and radiotherapy. Six months later the patient developed a second left frontal recurrence and was again treated with surgery and radiotherapy. Six weeks later, further recurrence was observed in the brain and bone, and biopsy confirmed metastases in the pelvic bones. To understand the clonal relationships between the four tumor instances and the origin of metastasis, we performed whole-genome sequencing of the intracranial tumors and the tumor located in the right iliac bone. We compared their mutational and copy-number profiles and inferred the clonal phylogeny. The tumors harbored shared alterations in GBM driver genes, including mutations in TP53, NF1, and RB1, and CDKN2A deletion. Whole-genome doubling was identified in the first recurrence and the extracranial metastasis. Comparisons of the metastatic to intracranial tumors highlighted a high similarity in molecular profile but contrasting evidence regarding the origin of the metastasis. Subclonal reconstruction suggested a parallel evolution of the recurrent tumors, and that the metastatic tumor was largely derived from the first recurrence. We conclude that metastasis in glioma can be a late event in tumorigenesis.

Gliosarcoma case report and review of the literature

Gliosarcoma is an unusual subtype of glioblastoma multiforme. Its characteristic features are biphasic configuration, constituting a definite, separate glial and sarcomatous differentiation, on histological evaluation. Herein, we present a rare case of Gliosarcoma that had presented only once in our center in last 13 years. A 60 years old, diabetic, hypertensive male patient came to e emergency department with disturbed level of consciousness and right sided hemiplegia which was progressive over four days. On examination he was, conscious, unoriented in time, person or place, his mouth deviated to left and vitally stable. After initial evaluation, CT scan and MRI were advised. These showed a complex left parieto-occipital heterogeneous mass lesion with cystic and solid components, measuring approximately 5.2x4cm. The mass lesion was seen displacing the occipital horn anteriorly and inferiorly with probable extension into the lateral ventricular cavity. There was no associated midline shift or definite herniation. The lesion was diagnosed as highly suggestive of brain tumor with a differential diagnosis of glioblastoma multiforme or ependymoma. Blood picture revealed a rapidly increasing level of anemia. Surgical intervention comprising left parieto-occipital craniotomy and near total resection of the tumor was carried out. On histopathological and immunohistochemical evaluation the diagnosis of GS was established. A plan of a combination of adjuvant chemotherapy and radiation was formulated that was however, declined by the family. On regular follow up, the patients clinical state rapidly deteriorated with persistence of seizures and requirement of repeated blood transfusions. The patient finally passed away after eighth months.

Primary Gliosarcoma with Extracranial Metastasis

A 69-year-old male presented with a week of worsening headache, mild dizziness and left side weakness, and the radiological work-up of his brain displayed an enhancing mass on the right frontal lobe. The tumor was totally resected. The patient was initially diagnosed with glioblastoma multiforme. His neurologic symptoms recovered after surgery. He underwent adjuvant radiotherapy with concurrent temozolomide. Approximately 7 months after surgery, the patient complained of epigastric pains. Abdominal CT scan showed multiple hepatic metastasis and multiple lymphadenopathy. Chest CT and Torso positron emission tomography-CT scans for additional metastasis study revealed multiple metastatic lesions in the right lung, left pleura, liver, lymph nodes, bones, and muscles. Percutaneous liver biopsy was performed, and associated pathology was consistent with sarcomatous component. After liver biopsy, brain tumor pathology was reviewed, which revealed typical gliomatous and sarcomatous components. The patient was therefore diagnosed with metastatic gliosarcoma. The patient was in a septic condition with aggravated pleural effusion. The patient died 9 months after the diagnosis of primary gliosarcoma.

Clinical Characteristics of Gliosarcoma and Outcomes From Standardized Treatment Relative to Conventional Glioblastoma

Background: Gliosarcoma (GS) is a rare histopathologic variant of glioblastoma (GBM) characterized by a biphasic growth pattern consisting of both glial and sarcomatous components. Reports regarding its relative prognosis compared to conventional GBM are conflicting and although GS is treated as conventional GBM, supporting evidence is lacking. The aim of this study was to characterize demographic trends, clinical outcomes and prognostic variables of GS patients receiving standardized therapy and compare these to conventional GBM. Methods: Six hundred and eighty GBM patients, treated with maximal safe resection followed by radiotherapy with concomitant and adjuvant temozolomide at a single institution, were retrospectively reevaluated by reviewing histopathological records and tumor tissue for identification of GS patients. Clinico-pathological- and tumor growth characteristics were obtained via assessment of medical records and imaging analysis. Kaplan-Meier survival estimates were compared with log-rank testing, while Cox-regression modeling was tested for prognostic factors in GS patients. Results: The cohort included 26 primary gliosarcoma (PGS) patients (3.8%) and 7 secondary gliosarcoma (SGS) patients (1.0%). Compared to conventional GBM tumors, PGS tumors were significantly more often MGMT-unmethylated (73.9%) and located in the temporal lobe (57.7%). GS tumors often presented dural contact, while extracranial metastasis was only found in 1 patient. No significant differences were found between PGS and conventional GBM in progression-free-survival (6.8 and 7.6 months, respectively, p = 0.105) and in overall survival (13.4 and 15.7 months, respectively, p = 0.201). Survival following recurrence was not significantly different between PGS, SGS, and GBM. Temporal tumor location and MGMT status were found associated with PGS survival (p = 0.036 and p = 0.022, respectively). Conclusion: Despite histopathological and location difference between GS and GBM tumors, the patients present similar survival outcome from standardized treatment. These findings support continued practice of radiation and temozolomide for GS patients.

Prognostic factors among single primary gliosarcoma cases: A study using Surveillance, Epidemiology, and End Results data from 1973-2013

Background

Prognostic factors for single primary gliosarcoma (PGS) remain unknown.

Objective

The purpose of our study was to examine patient, tumor, and treatment characteristics as potential predictors of survival using Surveillance, Epidemiology, and End Results (SEER) program data (1973‐2013).

Methods

The patients of single PGS were selected based on the exclusion criteria from SEER. Kaplan‐Meier survival analysis, log‐rank test and Cox proportional hazards models were used to analyze all the data.

Results

Single PGS has an apparent popularity for the temporal lobe (35.2%, hazard ratio [HR] = 0.440, 95%CI = 0.251‐0.770) and frontal lobe (20.9%, HR = 0.408, 95%CI = 0.231‐0.720) which could achieve a better survival rate than cerebrum (P = .034). The mean age at diagnosis was 60.07 ± 14.161. The overall 6‐month, 1‐year, 2‐year, and 5‐year survival was 55.40%, 29.58%, 10.01%, and 2.73%. Age at diagnosis was proved to be a significant predictor of overall survival (OS) (P < .001). There is no significant difference in race, marital status, or grade. Patients' tumor size which is located in 41‐60 mm (P = .047, HR = 1.468, 95%CI = 1.004‐2.147) and >60 mm (P= .003, HR = 1.899, 95%CI = 1.244‐2.901) showed a higher risk of death. Surgery played a critical role in OS (P < .001). Radiation after surgery was another predictor of OS of PGS (P < .001). Among all the radiation methods, combination of beam with implants or isotopes (P = .000, HR = 0.491, 95%CI = 0.412‐0.585) or radiation NOS (P = .027, HR = 0.362, 95%CI = 0.148‐0.889) were more beneficial to patients.

Conclusion

This study indicated that single PGS has a poor prognosis. Prognosis of single PGS would become poorer along with patients' age and tumor size (>40 mm). Surgery intervention and radiation therapy were beneficial factors.

Gliosarcoma: distinct molecular pathways and genomic alterations identified by DNA copy number/SNP microarray analysis

PURPOSE

Gliosarcoma is a histologic variant of glioblastoma (GBM), and like GBM carries a poor prognosis. Median survival is less than one (1) year with less than 5% of patients alive after 5 years. Although there is no cure, standard treatment includes surgery, radiation and chemotherapy. While very similar to GBM, gliosarcoma exhibits several distinct differences, morphologically and molecularly. Therefore, we report a comprehensive analysis of DNA copy number changes in gliosarcoma using a cytogenomic DNA copy number (CN) microarray (OncoScan®).

METHODS

Cytogenomic DNA copy number microarray (OncoScan®) was performed on 18 cases of gliosarcoma. MetaCore™ enrichment was applied to the array results to detect associated molecular pathways.

RESULTS

The most frequent alteration was copy number loss, comprising 57% of total copy number changes. The number of losses far exceeded the number of amplifications (***, < 0.001) and loss of heterozygosity events (***, < 0.001). Amplifications were infrequent (4.6%), particularly for EGFR. Chromosomes 9 and 10 had the highest number of losses; a large portion of which correlated to CDKN2A/B loss. Copy number gains were the second most common alteration (26.2%), with the majority occurring on chromosome 7. MetaCore™ enrichment detected notable pathways for copy number gains including: HOXA, Rho family of GTPases, and EGFR; copy number loss including: WNT, NF-kß, and CDKN2A; and copy number loss of heterozygosity including: WNT and p53.

CONCLUSIONS

The pathways and copy number alterations detected in this study may represent key drivers in gliosarcoma oncogenesis and may provide a starting point toward targeted oncologic analysis with therapeutic potential.

Prognosis and management of gliosarcoma patients: A review of literature

Gliosarcoma (GSM) is a variant of glioblastoma (GBM), the most common primary malignant brain tumor that occurs in adults. GSM is characterized by its biphasic components: the gliomatous and sarcomatous components and categorized into primary and secondary GSM. Intrinsic to the brain parenchyma, GSM is usually managed by gross total resection, and radiotherapy with/without chemotherapy. While the benefits of treatment remain unclear, cases have always been managed similar to GBM cases yielding different treatment outcomes between the two groups. The scarcity of research done on GSM suggests that further investigation is needed. Genetic studies on tumor samples and an in-depth examination of tumor subtypes and categories could result in identification of certain targetable alterations. The objective of this review is to summarize the available findings on characteristics, prognosis and management of GSM patients.

Evaluating the Association Between the Extent of Resection and Survival in Gliosarcoma

Introduction: Gliosarcoma (GS) is a rare, malignant mixed tumor of the central nervous system with a median survival of approximately 13 months across multiple studies. Although the value of the extent of resection (EOR) has been confirmed as a prognostic survival factor in glioblastoma, no such association has been defined for GS. The goal of this study was to establish an association between EOR and survival and to determine if a threshold of resection exists for which a survival benefit is conferred in GS.

Methods: The authors identified 11 patients with histologically confirmed GS between January 2005 and January 2015, treated at the Hospital of the University of Pennsylvania. Clinical, radiographic, and outcome data were retrospectively reviewed. Volumetric analysis was completed using semi-automated segmentation to measure the change in contrast-enhancing material based on preoperative T1-contrast (T1c) and postoperative T1 & T1c magnetic resonance imaging (MRI) scans. A log-rank test was completed to confirm an association between EOR and survival, and a series of Kaplan-Meier curves were constructed to determine an EOR threshold. Univariate Cox proportional hazards model (CPHM) followed by multivariate CPHM was also completed to evaluate associations between the prognostic clinical and immunohistochemistry variables under consideration.

Results: Extent of resection categories were defined as gross total resection (GTR >95%), subtotal resection (STR 90%-95%), and partial resection (PR <90%). The median overall survival for the groups were as follows: GTR-17.3 months (n=4), STR-12.6 months (n=5), PR-4.3 months (n=2). A statistically significant association (p=05 level) was found between survival and the PR group with the GTR group as reference. Multivariate CPHM confirmed a statistically significant association between increased survival and age, preoperative Karnofsky Performance Status (KPS) scores, postoperative KPS scores, and KI-67 index. Serial Kaplan-Meier curves suggest a survival benefit with an EOR threshold of 94%.

Conclusion: This study agrees with previous correlations in glioblastoma EOR and prolonged survival. For patients undergoing surgical resection for GS, maximal surgical removal, when safely possible, should be attempted as it appears to translate to longer survival times.

Glioblastoma heterogeneity and the tumour microenvironment: implications for preclinical research and development of new treatments

Glioblastoma is the deadliest form of brain cancer. Aside from inadequate treatment options, one of the main reasons glioblastoma is so lethal is the rapid growth of tumour cells coupled with continuous cell invasion into surrounding healthy brain tissue. Significant intra- and inter-tumour heterogeneity associated with differences in the corresponding tumour microenvironments contributes greatly to glioblastoma progression. Within this tumour microenvironment, the extracellular matrix profoundly influences the way cancer cells become invasive, and changes to extracellular (pH and oxygen levels) and metabolic (glucose and lactate) components support glioblastoma growth. Furthermore, studies on clinical samples have revealed that the tumour microenvironment is highly immunosuppressive which contributes to failure in immunotherapy treatments. Although technically possible, many components of the tumour microenvironment have not yet been the focus of glioblastoma therapies, despite growing evidence of its importance to glioblastoma malignancy. Here, we review recent progress in the characterisation of the glioblastoma tumour microenvironment and the sources of tumour heterogeneity in human clinical material. We also discuss the latest advances in technologies for personalised and in vitro preclinical studies using brain organoid models to better model glioblastoma and its interactions with the surrounding healthy brain tissue, which may play an essential role in developing new and more personalised treatments for this aggressive type of cancer.

Gliosarcoma Is Driven by Alterations in PI3K/Akt, RAS/MAPK Pathways and Characterized by Collagen Gene Expression Signature

Gliosarcoma is a very rare brain tumor reported to be a variant of glioblastoma (GBM), IDH-wildtype. While differences in molecular and histological features between gliosarcoma and GBM were reported, detailed information on the genetic background of this tumor is lacking. We intend to fill in this knowledge gap by the complex analysis of somatic mutations, indels, copy number variations, translocations and gene expression patterns in gliosarcomas. Using next generation sequencing, we determined somatic mutations, copy number variations (CNVs) and translocations in 10 gliosarcomas. Six tumors have been further subjected to RNA sequencing analysis and gene expression patterns have been compared to those of GBMs. We demonstrate that gliosarcoma bears somatic alterations in gene coding for PI3K/Akt (PTEN, PI3K) and RAS/MAPK (NF1, BRAF) signaling pathways that are crucial for tumor growth. Interestingly, the frequency of PTEN alterations in gliosarcomas was much higher than in GBMs. Aberrations of PTEN were the most frequent and occurred in 70% of samples. We identified genes differentially expressed in gliosarcoma compared to GBM (including collagen signature) and confirmed a difference in the protein level by immunohistochemistry. We found several novel translocations (including translocations in the RABGEF1 gene) creating potentially unfavorable combinations. Collected results on genetic alterations and transcriptomic profiles offer new insights into gliosarcoma pathobiology, highlight differences in gliosarcoma and GBM genetic backgrounds and point out to distinct molecular cues for targeted treatment.

Gliosarcoma in a young patient with neurofibromatosis type 1. Case report

Introducción. La neurofibromatosis tipo 1 (NF1) es una condición autosómica dominante que presenta una expresividad fenotípica variable, con manifestaciones que van desde lesiones cutáneas hasta compromiso funcional. Se manifiesta clínicamente durante la infancia y la adolescencia; su gen codifica una proteína, la neurofibromina, que actúa como un supresor tumoral en condiciones normales regulando, a su vez, otra proteína que estimula el crecimiento y proliferación celular. En caso de alteración se podrían presentar diferentes procesos tumorales como el que se evidencia en un reducido número de casos. Presentación de caso. Paciente masculino de 20 años con NF1, quien presentaba lesiones cutáneas como manchas color café con leche y desarrolló un glioblastoma, lo cual sucede de manera infrecuente. Discusión. Para obtener el diagnóstico confirmado se incluyen métodos de inmunohistoquímica que contribuyen en gran medida al pronóstico puesto que la mediana de supervivencia global de los pacientes de glioblastoma es mayor en pacientes con NF1 que aquellos sin dicha entidad patológica. Conclusión. El diagnóstico temprano de las lesiones favorece un manejo a tiempo de la NF1. Estos pacientes requieren un manejo integral e interdisciplinar para favorecer su rehabilitación total.

Gliosarcoma: a clinical and radiological analysis of 48 cases

OBJECTIVES

To retrospectively review the radiological and clinicopathological features of gliosarcoma (GSM) and differentiate it from glioblastoma multiforme (GBM).

METHODS

The clinicopathological data and imaging findings (including VASARI analysis) of 48 surgically and pathologically confirmed GSM patients (group 1) were reviewed in detail, and were compared with that of other glioblastoma (GBM) cases in our hospital (group 2).

RESULTS

There were 28 men and 20 women GSM patients with a median age of 52.5 years (range, 24-80 years) in this study. Haemorrhage (n = 21), a salt-and-pepper sign on T2-weighted images (n = 36), unevenly thickened wall (n = 36) even appearing as a paliform pattern (n = 32), an intra-tumoural large feeding artery (n = 32) and an eccentric cystic portion (ECP) (n = 19) were more commonly observed in the GSM group than in GBM patients. Based on our experience, GSM can be divided into four subtypes according to magnetic resonance imaging (MRI) features. When compared to GBM (group 2), there were more patients designated with type III lesions (having very unevenly thickened walls) and IV (solid) lesions among the GSM cases (group 1). On univariate prognostic analysis, adjuvant therapy (radiotherapy, chemotherapy, and radiochemotherapy) and existence of an eccentric cyst region were prognostic factors. However, Cox's regression model showed only adjuvant therapy as a prognostic factor for GSM.

CONCLUSIONS

When compared to GBM, certain imaging features are more likely to occur in GSM, which may help raise the possibility of this disease. All GSM patients are recommended to receive adjuvant therapy to achieve a better prognosis with radiotherapy, chemotherapy or radiochemotherapy all as options.

KEY POINTS

• Diagnosis of gliosarcoma can be suggested preoperatively by imaging. • Gliosarcoma can be divided into four subtypes based on MRI. • Paliform pattern and ECP tend to present in gliosarcoma more than GBM. • The cystic subtype of gliosarcoma may predict a more dismal prognosis. • All gliosarcoma patients should receive adjuvant therapy to achieve better prognosis.

Giant parieto-occipital lobe pediatric gliosarcoma: Report of a rare entity and review of literature

Background

Gliosarcoma is a rare high-grade malignant tumor and a variant of glioblastoma characterized by biphasic glial and mesenchymal components. Gliosarcomas occur most commonly in the fifth or sixth decade of life and have a temporal lobe predilection. Occurrence in the pediatric population is extremely rare.

Case Description

Here, we report the case of an 8-year-old child with histologically confirmed gliosarcoma at the parieto-occipital lobe. Only a subtotal resection of the tumor mass could be performed in view of massive bleeding from the tumor bed; and despite postoperative chemotherapy and radiotherapy, the tumor recurred in a short span of time. A repeat surgery was done but the patient could not survive.

Conclusion

To our knowledge, this case constitutes the second youngest case reported in the literature with the lesion in the parieto-occipital region and the third youngest in all pediatric cases of gliosarcoma. This case demonstrates that possibility of gliosarcoma should always be kept in mind in children presenting with features of intracranial high-grade glial tumor. This case also suggests that significant residual after surgery is one variable that may affect the prognosis despite radiotherapy and/or chemotherapy.

Gliosarcoma of Cerebello-Pontine Angle: A Case Report and Review of the Literature

Gliosarcoma (GS), known as variant of glioblastoma multiforme, is aggressive and very rare primary central nervous system malignant neoplasm. They are usually located in the supratentorial area with possible direct dural invasion or only reactive dural thickening. However, in this case, GS was located in lateral side of left posterior cranial fossa. A 78-year-old man was admitted to our hospital with 3 month history of continuous dizziness and gait disturbance without past medical history. A gadolinium-enhanced MRI demonstrated 5.6×4.8×3.2 cm sized mass lesion in left posterior cranial fossa, heterogeneously enhanced. The patient underwent left retrosigmoid craniotomy with navigation system. The tumor was combined with 2 components, whitish firm mass and gray colored soft & suckable mass. On pathologic report, the final diagnosis was GS of WHO grade IV. In spite of successful gross total resection of tumor, we were no longer able to treat because of the patient's rejection of adjuvant treatment. The patient survived for nine months without receiving any special treatment from the hospital.

Primary gliosarcoma: epidemiology, clinical presentation, management, and survival

BACKGROUND

Gliosarcomas are malignant tumors of the central nervous system. As a variant of glioblastomas (GBM), they are treated in a similar fashion. However, there is growing evidence to suggest that they may be a separate entity.

METHODS

Due to the rarity of primary gliosarcomas (PGS), here we publish data from a single center spanning over 14 years, comprising possibly one of the biggest case series in the literature to our knowledge.

RESULTS

The mean age at presentation was 59 years with male preponderance (1.75:1). The most common presenting symptoms were balance and mobility issues (61%), followed by headaches (50%) and visual problems (39%). Tumours were most likely to involve the frontal and parietal lobes (27% and 21% respectively). Patients under 50 had a significant survival advantage (50% versus 32%). All patients had surgery, 79% had adjuvant radiotherapy, with a further 21% also receiving chemotherapy. Median survival from surgery of patients diagnosed with PGS was 6.6 months. Median and one-year survival were significantly better for patients who received radiotherapy (14 months; 46% one year survival) and improved further with combined radio- and chemotherapy (30 months; 77%, one year survival).

CONCLUSIONS

For patients of good functional status, adjuvant chemo-radiotherapy is warranted and should be offered as it confers a much-improved overall survival.