Genetic profile of gliosarcomas

Metastatic glioblastoma to the lungs: a case report and literature review

Glioblastoma is the most common malignant primary brain tumor. Despite its infiltrative nature, extra-cranial glioblastoma metastases are rare. We present a case of a 63-year-old woman with metastatic glioblastoma in the lungs. Sarcomatous histology, a reported risk factor for disseminated disease, was found. Genomic alterations of TP53 mutation, TERT mutation, PTEN mutation, and +7/-10 were also uncovered. Early evidence suggests these molecular aberrations are common in metastatic glioblastoma. Treatment with third-line lenvatinib resulted in a mixed response. This case contributes to the growing body of evidence for the role of genomic alterations in predictive risk in metastatic glioblastoma. There remains an unmet need for treatment of metastatic glioblastoma.

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.

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.

Deep molecular tracking over the 12-yr development of endometrial cancer from hyperplasia in a single patient

Although the progressive histologic steps leading to endometrial cancer (EndoCA), the most common female reproductive tract malignancy, from endometrial hyperplasia are well-established, the molecular changes accompanying this malignant transformation in a single patient have never been described. We had the unique opportunity to investigate the paired histologic and molecular features associated with the 12-yr development of EndoCA in a postmenopausal female who could not undergo hysterectomy and instead underwent progesterone treatment. Using a specially designed 58-gene next-generation sequencing panel, we analyzed a total of 10 sequential biopsy samples collected over this time frame. A total of eight pathogenic/likely pathogenic mutations in seven genes, APC, ARID1A, CTNNB1, CDKN2A, KRAS, PTEN, and TP53, were identified. A PTEN nonsense mutation p.W111* was present in all samples analyzed except histologically normal endometrium. Apart from this PTEN mutation, the only other recurrent mutation was KRAS G12D, which was present in six biopsy samplings, including histologically normal tissue obtained at the patient's first visit but not detectable in the cancer. The PTEN p.W111* mutant allele fractions were lowest in benign, inactive endometrial glands (0.7%), highest in adenocarcinoma (36.9%), and, notably, were always markedly reduced following progesterone treatment. To our knowledge, this report provides the first molecular characterization of EndoCA development in a single patient. A single PTEN mutation was present throughout the 12 years of cancer development. Importantly, and with potential significance toward medical and nonsurgical management of EndoCA, progesterone treatments were consistently noted to markedly decrease PTEN mutant allele fractions to precancerous levels.

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.

An autopsy case of primary gliosarcoma with multiple extracranial metastases: pathology after administration of bevacizumab and genetic profile

Gliosarcoma (GS), a morphological variant of glioblastoma, pathologically shows a biphasic pattern with gliomatous and sarcomatous components. It has been reported that GS has much higher metastatic capacity than glioblastoma. A few reports on the pathology of the extracranial metastasis of GS have shown that metastatic lesions had a sarcomatous component alone or a mixture of gliomatous and sarcomatous ones. Therefore, it is considered that GS tends to disseminate hematogenously due to its mesenchymal sarcomatous component. Herein, we report an autopsy case of GS with multiple extracranial metastases treated by craniotomy, radiotherapy, and bevacizumab. In this case, metastatic lesions at autopsy contained a gliomatous component alone, but no sarcomatous component. In addition, the sarcomatous component disappeared from the intracranial lesion at autopsy after the administration of bevacizumab. In this report, we discuss the clinical course and pathological findings at the initial state, recurrence, and autopsy, including the results of whole-genome analysis.

Pediatric gliosarcoma, a rare central nervous system tumor in children: Case report and literature review

Gliosarcoma is a rare and highly malignant central nervous system tumor that accounts for 1%-8% of glioblastomas; it usually occurs in middle-aged and older adults between 40 and 60 years of age and is rare in children. We report an 11-year-old boy with right frontal lobe gliosarcoma who underwent aggressive gross total resection and postoperative radiotherapy, experienced recurrence and subsequently underwent a second operation. To better understand the disease and explore treatment options, we briefly report this case and review the relevant literature.

Gliosarcoma with extensive extracranial metastatic spread and familial coincidence: A case report

Gliosarcoma is a rare histopathological subtype of glioblastoma. Metastatic spreading is unusual. In this report, we illustrate a case of gliosarcoma with extensive extracranial metastases with confirmation of histological and molecular concordance between the primary tumor and a metastatic lesion of the lung. Only the autopsy revealed the extent of metastatic spread and the hematogenous pattern of metastatic dissemination. Moreover, the case bared a familial coincidence of malignant glial tumors as the patient's son was diagnosed with a high-grade glioma shortly after the patient's death. By molecular analysis (Sanger and next generation panel sequencing), we could confirm that both patient's tumors carried mutations in the TP53 gene. Interestingly, the detected mutations were located in different exons. Altogether, this case draws attention to the fact that sudden clinical aggravation could be caused by the rare phenomenon of metastatic spread and should therefore be always taken into consideration, even at an early disease stage. Furthermore, the presented case highlights the contemporary value of autoptic pathological examination.

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.

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.

A Unique Case Report of Infant-Type Hemispheric Glioma (Gliosarcoma Subtype) with TPR-NTRK1 Fusion Treated with Larotrectinib

Herein, we present a rare case of a nine-month-old boy diagnosed with infant-type hemispheric glioma (gliosarcoma subtype) at the left frontal lobe. Following subtotal resection, the patient started chemotherapy with the BABY POG protocol. We describe the clinical diagnosis, histological characteristics, radiological features, molecular aspects, and management of this tumor. A comprehensive molecular analysis on the tumor tissue showed a TPR-NTRK1 gene fusion. The patient was treated with a TRK inhibitor, larotrectinib, and exhibited a stable disease with residual lesion following 8 months of target therapy. The present study is the first report of an infantile gliosarcoma harboring NTRK1 rearrangement treated with larotrectinib.

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.

Pediatric Gliosarcoma With and Without Neurofibromatosis Type 1: A Whole-exome Comparison of 2 Patients

Gliosarcoma is rare among pediatric patients and among individuals with Neurofibromatosis Type 1 (NF1). Here we compare 2 pediatric gliosarcoma patients, one of whom has NF1. We performed whole-exome sequencing, methylation, and copy number analysis on tumor and blood for both patients. Whole-exome sequencing showed higher mutational burden in the tumor of the patient without NF1. Copy number analysis showed differences in chromosomal losses/gains between the tumors. Neither tumor showed O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation. The NF1 patient survived without progression while the other expired. This is the first reported case of gliosarcoma in a child with NF1.

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.

Ependymosarcoma harboring C11orf95:RELA fusion transcript: Report of two cases and review of the literature

Ependymoma is a relatively rare glial tumor of the central nervous system that arise from the cells lining the ventricles and central canal of the spinal cord. Ependymosarcoma (ES) is a newly introduced tumor entity of uncertain prognosis characterized by a rare phenomenon of a malignant mesenchymal transition arising within an ependymoma. ESs are surgically challenging tumors for diagnosis and therapy with a high incidence of morbidity and mortality. Here, we report two diagnostically challenging cases of primary ES in a 25-year-old female and a 17-year-old male. Both the cases presented with progressive and sequential neurological deficits over a period of five to eight months, and histological examination revealed a biphasic gliomesenchymal architecture comprised of anaplastic ependymomatous and sarcomatous components. Molecular genetic analysis revealed the presence of type 1 C11orf95:RELA fusion transcript. To date, 22 cases of ES have been reported in the literature, and only one case harbored type 1 C11orf95:RELA fusion transcript.

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.

Morphologic and Molecular Aspects of Glioblastomas

The definition of glioblastomas has continually evolved from a reliance on strict morphologic features to a combination of histologic and molecular criteria, as the understanding of the genetic basis of these tumors expands. Modern pathologic workup of glioblastomas includes intraoperative evaluations with tissue-sparing techniques, histologic assessment with immunohistochemical markers, and comprehensive molecular characterization aiming at personalized targeting of genetic abnormalities. Machine learning analysis of DNA methylation profiles is a breakthrough technology that has bolstered central nervous system tumor classification and discovery and is particularly beneficial for the diagnosis and subtyping of glioblastomas.

TERT Promoter Alterations in Glioblastoma: A Systematic Review

Simple Summary

Glioblastoma is the most common malignant primary brain tumor in adults. Glioblastoma accounts for 2 to 3 cases per 100,000 persons in North America and Europe. Glioblastoma classification is now based on histopathological and molecular features including isocitrate dehydrogenase (IDH) mutations. At the end of the 2000s, genome-wide sequencing of glioblastoma identified recurrent somatic genetic alterations involved in oncogenesis. Among them, the alterations in the promoter region of the telomerase reverse transcriptase (TERTp) gene are highly recurrent and occur in 70% to 80% of all glioblastomas, including glioblastoma IDH wild type and glioblastoma IDH mutated. This review focuses on recent advances related to physiopathological mechanisms, diagnosis, and clinical implications.

Abstract

Glioblastoma, the most frequent and aggressive primary malignant tumor, often presents with alterations in the telomerase reverse transcriptase promoter. Telomerase is responsible for the maintenance of telomere length to avoid cell death. Telomere lengthening is required for cancer cell survival and has led to the investigation of telomerase activity as a potential mechanism that enables cancer growth. The aim of this systematic review is to provide an overview of the available data concerning TERT alterations and glioblastoma in terms of incidence, physiopathological understanding, and potential therapeutic implications.

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.

Demographic, radiographic, molecular and clinical characteristics of primary gliosarcoma and differences to glioblastoma

OBJECTIVE

Gliosarcoma (GSC) is a rare histological variant of glioblastoma (GBM). Due to limited evidence regarding clinical, genetic and radiographic characteristics of GSC, this study aimed to analyze independent outcome predictors of GSC, and to address the differences between GSC and GBM concerning the baseline characteristics and patients' survival.

METHODS

Patients treated between 2001 and 2018 for the diagnosis of GBM and GSC were included in this study. Patients' records were reviewed for demographic, clinical, genetic and radiographic characteristics. Univariate, multivariate and propensity score matched analyses were performed.

RESULTS

In the GSC sub-cohort (N = 56), patients' age, preoperative clinical status, midline tumor location and tumor size were found to be independently associated with overall survival. As compared to GBM individuals (N = 1249), a temporal location (p = 0.002), presence of eccentric tumor cysts (p < 0.001), a higher ratio of TP53 staining (p = 0.002) and a lower ratio of GFAP staining (p = 0.005) were characteristic for GSC. The diagnosis of GSC was associated with a poorer survival (p = 0.002) independently of the patients' age, sex, clinical status and extent of resection, However, this association was no more significant, when enhancing the multivariate analysis with molecular-genetic characteristics (IDH1 mutation and MGMT promotor methylation status).

DISCUSSION

Certain radiographic and molecular-genetic patterns present the distinct characteristics of GSC. There is an association between the diagnosis of GSC and a poorer outcome. This difference might be linked to different genetic alterations in GBM and GSC. Prospective studies are needed to further elucidate the characteristics of GSC and develop targeted treatment approaches for this rare variant.

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.

RELA fusion-positive ependymoma accompanied by extensive desmoplasia: a case report

We report a case of 33-year-old Japanese male who presented with a headache and visual disturbances. Magnetic resonance imaging revealed a large tumor in the left frontal lobe, measuring 7 cm in diameter, which was diagnosed as supratentorial anaplastic ependymoma accompanied by extensive desmoplasia. The patient underwent a gross total resection. Histologically, the tumor cells had oval or short, spindle-shaped nuclei, and proliferating cells in perivascular pseudorosettes with anucleate zones and mitotic figures. Desmoplasia with abundant collagen fibers among the tumor cells was detected at numerous sites, and perinuclear dot- or ring-like immunoreactivity for epithelial membrane antigen was identified. Five years and six months after the initial procedure, a small recurrent tumor was identified at the removal site. The patient underwent a second total resection. The histology of the resected tumor showed decreased collagen production and more apparent anaplastic features as compared to those of the initial tumor. In addition to the histological findings, molecular examinations revealed ependymoma, RELA fusion positive. Although not commonly observed, this case suggests that desmoplasia could be associated with ependymomas, including RELA fusion-positive variant. Moreover, our findings indicate that high-grade ependymoma requires careful, long-term follow-up even if gross total resection is performed.

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.

Genetic and histologic spatiotemporal evolution of recurrent, multifocal, multicentric and metastatic glioblastoma

Glioblastoma is the most frequent and aggressive primary brain tumor, characterized by extensive brain invasion and rarely, systemic metastases. The pathogenesis of metastatic glioblastoma is largely unknown. We present the first integrated clinical/histologic/genetic analysis of 5 distinct brain and lung foci from a unique case of recurrent, multifocal, multicentric and metastatic glioblastoma. The initial right frontotemporal gliosarcoma received standard surgical/chemoradiation therapy and recurred 1.5 years later, co-occurring with three additional masses localized to the ipsilateral temporal lobe, cerebellum and lung. Synchronous metastatic lung carcinoma was suspected in this long-term smoker patient with family history of cancer. However, glioblastoma was confirmed in all tumors, although with different morphologic patterns, including ependymomatous and epithelioid. Genomic profiling revealed a germline FANCD2 variant of unknown significance, and a 4-gene somatic mutation signature shared by all tumors, consisting of TERT promoter and PTEN, RB1 and TP53 tumor suppressor mutations. Additional GRIN2A and ATM heterozygous mutations were selected in the cerebellar and lung foci, but were variably present in the supratentorial foci, indicating reduced post-therapeutic genetic evolution in brain foci despite morphologic variability. Significant genetic drift characterized the lung metastasis, likely explaining the known resistance of circulating glioblastoma cells to systemic seeding. MET overexpression was detected in the initial gliosarcoma and lung metastasis, possibly contributing to invasiveness. This comprehensive analysis sheds light on the temporospatial evolution of glioblastoma and underscores the importance of genetic testing for diagnosis and personalized therapy.

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.

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 and clinical outcomes in adult primary gliosarcoma patients: a Surveillance, Epidemiology, and End Results (SEER) analysis from 2004 to 2015

Objective: Gliosarcoma (GSC), a rare malignant brain tumor, is considered as a variant of isocitrate dehydrogenase 1 wild type (IDH1-WT) glioblastoma (GBM). This study aimed to retrospectively analyze the clinical characteristics of GSC and compare whether there are some differences of treatment strategies and outcomes between GSC and GBM patients through Surveillance, Epidemiology, and End Results (SEER) database.Patients and methods: The clinical data of adults diagnosed with primary GSC between 2004 and 2015 were queried from SEER database. The Kaplan-Meier curve and the Cox model were performed to analyze the relationships between clinical parameters and patients' prognosis. Similar analyses were conducted for all primary GBM patients of SEER.Results: In total, 527 GSC and 20,541 GBM patients with complete and valid clinical information were finally enrolled for further analysis. Compared with GBM, GSC owned a proclivity to temporal lobe rather than frontal lobe (p < 0.001), a less conservative extension of resection (EOR) (p < 0.001), and a higher sensitivity to radiotherapy (p < 0.001). As shown by univariate analysis, surgery, radiotherapy and chemotherapy could prolong the overall survival (OS) time of GSC, but EOR did not confer an advantage to the outcomes of patients, no matter whether combined radio/chemotherapy was given. In multivariate analysis, age more than 60 and lack of radio/chemotherapy were identified as independent risk factors for OS of GSC patients.Conclusions: Our study found that although EOR seemed to be important to GBM, the extent of surgery did not show a clear relationship with the improved prognosis of GSC. Additionally, radiotherapy and chemotherapy could prolong patients' survival time significantly, which suggests a more positive role of them in treating GSC and needs further investigations.

Cerebral gliosarcoma with perivascular involvement in a cat

Case summary

A 5-year-old neutered male domestic shorthair cat presented with an 18-month history of facial tics, and progressive general ataxia, weakness, lethargy and anorexia of 2 weeks’ duration. MRI of the brain showed a well-defined heterogeneous hyperintense mass on T1-weighted and T2-weighted images, with central hypointensity in the rostral commissure and septum pellucidum, and perilesional hyperintensity in fluid-attenuated inversion recovery, suggestive of perilesional oedema. Gross examination in a transverse section of the brain at the level of the septum pellucidum revealed a 0.2 cm brown soft mass. Histopathological examination identified a biphasic neoplastic proliferation of mesenchymal and neuroepithelial cell populations. Fusiform cells were predominately distributed in bundles showing a high degree of anisocytosis and marked immune-positive reaction to vimentin immunochemistry, confirming a sarcomatous origin. Additionally, high numbers of astrocytic cells were identified by an intense immunopositive reaction to glial fibrillary acidic protein and negative reaction to oligodendrocyte transcription factor 2 immunochemistry. Vascular invasion of the neoplasia into the wall of a medium branch of the rostral cerebral artery was present (secondary Scherer structures). Based on these characteristics, the tumour was defined as a gliosarcoma. Gliosarcoma is a recognised astrocytoma grade IV anaplastic glial cell tumour with sarcomatous differentiation.

Relevance and novel information

To our knowledge, this is the first report describing a cerebral gliosarcoma in a cat including clinical, MRI, macroscopic and histopathological features and immunolabelling characteristics.

LKB1 deficiency promotes proliferation and invasion of glioblastoma through activation of mTOR and focal adhesion kinase signaling pathways

Liver kinase B1 (LKB1), a serine/threonine kinase, is frequently inactivated in several types of human cancers. To date, inactivation of LKB1 tumor suppressor has rarely been reported in glioblastoma. In this study, we investigated LKB1 status, biological significance, and therapeutic implications in glioblastoma. Loss of LKB1 immunostaining was identified in 8.6% (5/58), while decrease of LKB1 immunostaining was found in 29.3% (17/58) of glioblastoma tissues. Notably, mining TCGA database of LKB1 expression in glioblastoma revealed that lower mRNA level of LKB1 was associated with shorter survival in glioblastoma. We found that knockdown of LKB1 significantly promoted in vitro proliferation, adhesion, invasion, and metformin-induced apoptosis, and simultaneously enhanced activation of ERK and mammalian-target of rapamycin (mTOR) signaling pathways in LKB1-compenent U87 and T98 glioblastoma cells. Moreover, global transcriptional profiling revealed that adhesion and cytoskeletal proteins such as Vinculin, Talin and signaling pathways including focal adhesion kinase (FAK), extracellular martrix (ECM) receptor interaction, and cellular motility were significantly enriched in U87 and T98 glioblastoma cells upon LKB1 knockdown. Additionally, we demonstrated that the enhanced activation of FAK by LKB1 knockdown was dependent on differentially expressed cytoskeletal proteins in these glioblastoma cells. Importantly, we further found that mTOR1 inhibitor rapamycin dominantly inhibited in vitro cellular proliferation, while FAK inhibitor PF-573288 drastically decreased invasion of LKB1-attenuated glioblastoma cells. Therefore, downregulation of LKB1 may contribute to the pathogenesis and malignancy of glioblastoma and may have potential implications for stratification and treatment of glioblastoma patients.

Gliosarcoma in a Young Filipino Woman: A Case Report and Review of the Literature

Patient: Female, 28

Final Diagnosis: Gliosarcoma

Symptoms: Foot drop

Medication: —

Clinical Procedure: —

Specialty: Neurosurgery

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.

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.

An experimental design framework for Markovian gene regulatory networks under stationary control policy

BACKGROUND

A fundamental problem for translational genomics is to find optimal therapies based on gene regulatory intervention. Dynamic intervention involves a control policy that optimally reduces a cost function based on phenotype by externally altering the state of the network over time. When a gene regulatory network (GRN) model is fully known, the problem is addressed using classical dynamic programming based on the Markov chain associated with the network. When the network is uncertain, a Bayesian framework can be applied, where policy optimality is with respect to both the dynamical objective and the uncertainty, as characterized by a prior distribution. In the presence of uncertainty, it is of great practical interest to develop an experimental design strategy and thereby select experiments that optimally reduce a measure of uncertainty.

RESULTS

In this paper, we employ mean objective cost of uncertainty (MOCU), which quantifies uncertainty based on the degree to which uncertainty degrades the operational objective, that being the cost owing to undesirable phenotypes. We assume that a number of conditional probabilities characterizing regulatory relationships among genes are unknown in the Markovian GRN. In sum, there is a prior distribution which can be updated to a posterior distribution by observing a regulatory trajectory, and an optimal control policy, known as an "intrinsically Bayesian robust" (IBR) policy. To obtain a better IBR policy, we select an experiment that minimizes the MOCU remaining after applying its output to the network. At this point, we can either stop and find the resulting IBR policy or proceed to determine more unknown conditional probabilities via regulatory observation and find the IBR policy from the resulting posterior distribution. For sequential experimental design this entire process is iterated. Owing to the computational complexity of experimental design, which requires computation of many potential IBR policies, we implement an approximate method utilizing mean first passage times (MFPTs) - but only in experimental design, the final policy being an IBR policy.

CONCLUSIONS

Comprehensive performance analysis based on extensive simulations on synthetic and real GRNs demonstrate the efficacy of the proposed method, including the accuracy and computational advantage of the approximate MFPT-based design.

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 with primitive neuronal, chondroid, osteoid and ependymal elements

A 51-year-old man presented with a 2-week history of malaise. MRI revealed a large solid and cystic lesion with ring enhancement measuring 6.5 cm in diameter in the right frontal lobe. Histologically, the tumor consisted of various components: diffuse growth of atypical astrocytic cells consistent with glioblastoma, fascicular proliferation of atypical spindle cells such as fibrosarcoma, clusters of primitive neuronal cells, and foci of ependymal cells. The sarcomatous component also focally exhibited chondroid and osteoid differentiation. Immunohistochemically, tumor cells in the primitive neuronal component were immunoreactive for synaptophysin and CD56. The spindle cells were immunopositive for Slug and Twist, regulators of epithelial-mesenchymal transition. Direct DNA sequencing demonstrated C228T mutation in the TERT promoter in astrocytic, sarcomatous and primitive neuronal components, suggesting their identical origin. Although a few cases of gliosarcoma with primitive neuronal differentiation have previously been described, the finding that neuronal, glial and sarcomatous components share an identical mutation of the TERT promoter has not been reported. The tumor recurred at the original site 11 months after the first surgery. Interestingly, the recurrent tumor was composed exclusively of a glioblastomatous component, unlike past cases of recurrent gliosarcoma.

Gliosarcomas in the Elderly: Analysis of 7 Cases and Clinico-Pathological Remarks

Aims and Background

Gliosarcomas are rare malignant primary brain tumors that usually affect the fifth or sixth decades of life. The purpose of this study was to describe our experience with such lesions in elderly patients and to establish their prognosis factors.

Methods

Between 1993 and 2001, 7 patients over 60 years of age were treated at our institute for cerebral gliosarcomas. All patients underwent surgery for total or at least sub-total removal of a neoplastic mass.

Results

Owing to poor clinical conditions (Karnofsky performance score = 40), one patient was not treated postoperatively. Remaining patients were treated with whole-brain radiotherapy, whereas concomitant chemotherapy (temozolomide) was administrated only to 4 patients. Histological examination showed the prevalence of sarcomatous aspects in 3 patients; the gliomatous aspect prevailed in 4 patients.

Conclusions

Sarcomatous aspects and multimodality treatment (surgery, radiotherapy and chemotherapy) were associated with a better prognosis and showed in these elderly patients a trend similar to that of young people.

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.

Treatment-associated TP53 DNA-binding domain missense mutations in the pathogenesis of secondary gliosarcoma

Background

Gliosarcoma is a rare variant of glioblastoma (GBM) that exhibits frequent mutations in TP53 and can develop in a secondary fashion after chemoradiation of a primary GBM. Whether temozolomide (TMZ)-induced mutagenesis of the TP53 DNA-binding domain (DBD) can drive the pathogenesis of gliosarcoma is unclear.

Methods

We identified a case of a primary GBM that rapidly progressed into secondary gliosarcoma shortly after chemoradiation was initiated. Bulk tumor was collected and gliomasphere cultures derived from both the pre- and post-treatment tumors. We performed targeted DNA sequencing and transcriptome analyses of the specimens to understand their phylogenetic relationship and identify differentially expressed gene pathways. Gliomaspheres from the primary GBM were treated with TMZ and then analyzed to compare patterns of mutagenesis in vivo and ex vivo.

Results

The pre- and post-treatment tumors shared EGFR, CDKN2A, and PTEN mutations, but only the secondary gliosarcoma exhibited TP53 DBD missense mutations. Two mutations, R110C, and R175H, were identified, each in distinct clones. Both were base transitions characteristic of TMZ mutagenesis. Gene expression analysis identified increased JAK-STAT signaling in the gliosarcoma, together with reduced expression of microRNAs known to regulate epithelial-mesenchymal transition. Ex vivo treatment of the GBM spheres with TMZ generated numerous variants in cancer driver genes, including TP53 and CDH1, which were mutated in the post-treatment tumor.

Conclusions

TMZ-induced TP53 gain-of-function mutations can have a driving role in secondary gliosarcoma pathogenesis. Analysis of variants identified in ex vivo TMZ-treated gliomaspheres may have utility in predicting GBM evolutionary trajectories in vivo during standard chemoradiation.

Clinical and molecular characteristics of gliosarcoma and modern prognostic significance relative to conventional glioblastoma

Gliosarcoma is a rare histopathologic variant of glioblastoma traditionally associated with a poor prognosis. While gliosarcoma may represent a distinct clinical entity given its unique histologic composition and molecular features, its relative prognostic significance remains uncertain. While treatment of gliosarcoma generally encompasses the same standardized approach used in glioblastoma, supporting evidence is limited given its rarity. Here, we characterized 32 cases of gliosarcoma and retrospectively evaluated survival relative to 451 glioblastoma patients diagnosed during the same era within the same institution. Overall, we identified 22 primary gliosarcomas, representing 4.7% of WHO Grade IV primary glioblastomas, and 10 secondary gliosarcomas. With median age of 62, patients were predominately Caucasian (87.5%) and male (65.6%). Tumors with available molecular profiling were primarily MGMT-unmethylated (87.5%), IDH-1-preserved (100%) and EGFR wild-type (100%). Interestingly, while no significant median survival difference between primary gliosarcoma and glioblastoma was observed across the entire cohort (11.0 vs. 14.8 months, p = 0.269), median survival was worse for gliosarcoma specifically among patients who received modern temozolomide-based (TMZ) chemoradiotherapy (11.0 vs. 17.3 months, p = 0.006). Matched-pair analysis also trended toward worse median survival among gliosarcomas (11.0 vs. 19.6 months, log-rank p = 0.177, Breslow p = 0.010). While adjuvant radiotherapy (HR 0.206, p = 0.035) and TMZ-based chemotherapy (HR 0.531, p = 0.000) appeared protective, gliosarcoma emerged as a significantly poor prognostic factor on multivariate analysis (HR 3.27, p = 0.012). Collectively, our results suggest that gliosarcoma may still portend worse prognosis even with modern trimodality therapy.

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.

Gliosarcomas with the BRAF V600E mutation: a report of two cases and review of the literature

Gliosarcoma, which is regarded as a variant of glioblastoma, is a rare malignant neoplasm of the central nervous system. Both its sarcomatous component and glial component are reported to share significant clinical and genetic similarities. However, gliosarcomas are considered to be characterised by a lack of the BRAF V600E mutation. Here, we report two cases of gliosarcoma harbouring the BRAF V600E mutation, of which one case appears to have arisen de novo, while the other likely arose from ganglioglioma. Interestingly, the BRAF V600E mutation was detected only in the glial component in the first case, but was present in both the glial and the sarcomatous components in the recurrent gliosarcoma. Furthermore, the different mutation state of BRAF V600E in our two cases suggests that the malignant transformation of gliosarcoma might have different underlying genetic alterations and mechanisms in de novo versus recurrent gliosarcoma.

Detailed magnetic resonance imaging features of a case series of primary gliosarcoma

Objective We aimed to characterise the magnetic resonance imaging (MRI) features of a case series of primary gliosarcoma, with the inclusion of diffusion-weighted imaging and perfusion imaging with dynamic susceptibility contrast MRI. Materials and methods We conducted a retrospective study of cases of primary gliosarcoma from the Pathology Department database from January 2006 to December 2014. Clinical and demographic data were obtained. Two neuroradiologists, blinded to diagnosis, assessed tumour location, signal intensity in T1 and T2-weighted images, pattern of enhancement, diffusion-weighted imaging and dynamic susceptibility contrast MRI studies on preoperative MRI. Results Seventeen patients with primary gliosarcomas had preoperative MRI study: seven men and 10 women, with a mean age of 59 years (range 27-74). All lesions were well demarcated, supratentorial and solitary (frontal n = 5, temporal n = 4, parietal n = 3); 13 tumours abutted the dural surface (8/13 with dural enhancement); T1 and T2-weighted imaging patterns were heterogeneous and the majority of lesions (12/17) showed a rim-like enhancement pattern with focal nodularities/irregular thickness. Restricted diffusion (mean apparent diffusion coefficient values 0.64 × 10^-3 mm²/s) in the more solid/thick components was present in eight out of 11 patients with diffusion-weighted imaging study. Dynamic susceptibility contrast MRI study ( n = 8) consistently showed hyperperfusion in non-necrotic/cystic components on relative cerebral volume maps. Conclusions The main distinguishing features of primary gliosarcoma are supratentorial and peripheral location, well-defined boundaries and a rim-like pattern of enhancement with an irregular thick wall. Diffusion-weighted imaging and relative cerebral volume map analysis paralleled primary gliosarcoma with high-grade gliomas, thus proving helpful in differential diagnosis.

Analysis of Outcomes of Multidisciplinary Management of Gliosarcoma: A Single-Center Study, 2000-2013

BACKGROUND

Gliosarcoma is a rare tumor of the central nervous system with a reported incidence of ∼2%-8% of all gliomas. We reviewed the outcomes of patients treated at our institution over a 14-year period from 2000 to 2013 to characterize overall survival (OS) and progression-free survival as well as to elucidate the additive effect of chemoradiotherapy.

METHODS

From January 1, 2000 to December 31, 2013, we retrospectively reviewed the clinical notes of all patients treated at our institution with a histopathologic diagnosis of gliosarcoma. This review yielded 21 patients whose clinicoradiologic data were analyzed with respect to age, sex, ethnicity, preoperative/postoperative Glasgow Coma Scale and Karnofsky Performance Scale, location, extent of resection, methylguanine DNA methyl transferase methylation status, and administration of adjuvant therapy.

RESULTS

The median age was 58 years (range, 40-80 years) with a male preponderance (1.6:1). Tumor location was mainly temporal (n = 6) but also parietal (n = 5), frontal (n = 4), multilobar (n = 4), and cerebellar (n = 1). Surgical resection was deemed to be total in 15 patients and subtotal in 6 patients. Methylguanine DNA methyl transferase methylation status was available for only 5 patients, with a methylation rate of 60% (3/5) and no impact on survival. Nine patients received both radiotherapy and chemotherapy (OS, 7.9 months), 7 received radiotherapy only (OS, 5.7 months), and 5 patients received no adjuvant therapy (OS, 1.4 months). The overall median survival was 5.7 months (range, 1-21.5 months) and median progression-free survival was 5 months (range, 1.4-12.4 months).

CONCLUSIONS

Despite an overall poor prognosis, a multimodality approach aiming for complete resection followed by radiotherapy and chemotherapy appears to be associated with better outcomes.

AKT can modulate the in vitro response of HNSCC cells to irreversible EGFR inhibitors

Epidermal growth factor receptor (EGFR) is overexpressed in up to 90% of head and neck squamous cell carcinoma (HNSCC) tumors. Cetuximab is the first targeted (anti-EGFR) therapy approved for the treatment of HNSCC patients. However, its efficacy is limited due to primary and secondary resistance, and there is no predict biomarkers of response. New generation of EGFR inhibitors with pan HER targeting and irreversible action, such as afatinib and allitinib, represents a significant therapeutic promise. In this study, we intend to compare the potential cytotoxicity of two anti-EGFR inhibitors (afatinib and allitinib) with cetuximab and to identify potential predictive biomarkers of response in a panel of HNSCC cell lines. The mutational analysis in the eight HNSCC cell lines revealed an EGFR mutation (p.H773Y) and gene amplification in the HN13 cells. According to the growth inhibition score (GI), allitinib was the most cytotoxic drug, followed by afatinib and finally cetuximab. The higher AKT phosphorylation level was associated with resistance to anti-EGFR agents. Therefore, we further performed drug combinations with anti-AKT agent (MK2206) and AKT1 gene editing, which demonstrated afatinib and allitinib sensitivity restored. Additionally, in silico analysis of TCGA database showed that AKT1 overexpression was present in 14.7% (41/279) of HNSCC cases, and was associated with perineural invasion in advanced stage. In conclusion, allitinib presented a greater cytotoxic profile when compared to afatinib and cetuximab. AKT pathway constitutes a predictive marker of allitinib response and combination with AKT inhibitors could restore response and increase treatment success.

High prevalence of TP53 mutations is associated with poor survival and an EMT signature in gliosarcoma patients

Gliosarcoma (GS) is a rare variant (2%) of glioblastoma (GBM) that poses clinical genomic challenges because of its poor prognosis and limited genomic information. To gain a comprehensive view of the genomic alterations in GS and to understand the molecular etiology of GS, we applied whole-exome sequencing analyses for 28 GS cases (6 blood-matched fresh-frozen tissues for the discovery set, 22 formalin-fixed paraffin-embedded tissues for the validation set) and copy-number variation microarrays for 5 blood-matched fresh-frozen tissues. TP53 mutations were more prevalent in the GS cases (20/28, 70%) compared to the GBM cases (29/90, 32%), and the GS patients with TP53 mutations showed a significantly shorter survival (multivariate Cox analysis, hazard ratio=23.9, 95% confidence interval, 2.87-199.63, P=0.003). A pathway analysis showed recurrent alterations in MAPK signaling (EGFR, RASGRF2 and TP53), phosphatidylinositol/calcium signaling (CACNA1s, PLCs and ITPRs) and focal adhesion/tight junction (PTEN and PAK3) pathways. Genomic profiling of the matched recurrent GS cases detected the occurrence of TP53 mutations in two recurrent GS cases, which suggests that TP53 mutations play a role in treatment resistance. Functionally, we found that TP53 mutations are associated with the epithelial-mesenchymal transition (EMT) process of sarcomatous components of GS. We provide the first comprehensive genome-wide genetic alternation profiling of GS, which suggests novel prognostic subgroups in GS patients based on their TP53 mutation status and provides new insight in the pathogenesis and targeted treatment of GS.