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

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.

Adult type diffuse gliomas in the new 2021 WHO Classification

Adult-type diffuse gliomas represent a group of highly infiltrative central nervous system tumors with a prognosis that significantly varies depending on the specific subtype and histological grade. Traditionally, adult-type diffuse gliomas have been classified based on their morphological features with a great interobserver variability and discrepancy in patient survival even within the same histological grade. Over the last few decades, advances in molecular profiling have drastically changed the diagnostic approach and classification of brain tumors leading to the development of an integrated morphological and molecular classification endowed with a more clinically relevant value. These concepts were largely anticipated in the revised fourth-edition of WHO classification of central nervous system tumors published in 2016. The fifth-edition (WHO 2021) moved molecular diagnostics forward into a full integration of molecular parameters with the histological features into an integrative diagnostic approach. Diagnosis of adult type diffuse gliomas, IDH mutant and IDH-wildtype has been simplified by introducing revised diagnostic and grading criteria. In this review, we will discuss the most recent updates to the classification of adult-type diffuse gliomas and summarize the essential diagnostic keys providing a practical guidance to pathologists.

Computed Tomography, Magnetic Resonance Imaging, and Pathological Features of Gliosarcoma

OBJECTIVE

To investigate the clinical, imaging, and pathological features of gliosarcoma.

METHODS

The clinical data of 14 patients with gliosarcoma confirmed by surgery and pathology at our hospital between 2010 and 2021 were analyzed retrospectively, and the relevant literature was reviewed.

RESULTS

In all 14 cases, the gliosarcoma was located in the supratentorial brain parenchyma and involved a single lesion. There were more male patients (64.3%) than female patients (35.7%), and 57.1% of all the patients were 40-60 years of age. The prognosis of all 14 patients was poor, and the average survival time was approximately seven months. The computed tomography findings revealed mostly mixed density lesions, and some cases were complicated with bleeding. The magnetic resonance imaging revealed irregularly shaped mass lesions of different sizes, with uneven or circular enhancement. Cystic degeneration and necrosis could be seen in all the masses, some of which showed signs of bleeding and were surrounded by different degrees of edema and space-occupying effects. The pathological examination revealed that the tumors had bidirectional differentiation of the glial and sarcoma components, while the immunohistochemistry examination revealed glial fibrillary acidic protein-positive and reticular fiber-positive staining in the sarcoma.

CONCLUSION

The clinical manifestations of gliosarcoma are nonspecific, but imaging reveals that the condition has certain characteristics, typically consisting of a huge supratentorial mass, with an irregular heterogeneous periphery or obvious mass-like augmentation after enhancement. The final diagnosis depends on the results of a pathological examination.

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.

Clinical characteristics and disease-specific prognostic nomogram for primary gliosarcoma: a SEER population-based analysis

Because the study population with gliosarcoma (GSM) is limited, the understanding of this disease is insufficient. In this study, the authors aimed to determine the clinical characteristics and independent prognostic factors influencing the prognosis of GSM patients and to develop a nomogram to predict the prognosis of GSM patients after craniotomy. A total of 498 patients diagnosed with primary GSM between 2004 and 2015 were extracted from the 18 Registries Research Data of the Surveillance, Epidemiology, and End Results (SEER) database. The median disease-specific survival (DSS) was 12.0 months, and the postoperative 0.5-, 1-, and 3-year DSS rates were 71.4%, 46.4% and 9.8%, respectively. We applied both the Cox proportional hazards model and the decision tree model to determine the prognostic factors of primary GSM. The Cox proportional hazards model demonstrated that age at presentation, tumour size, metastasis state and adjuvant chemotherapy (CT) were independent prognostic factors for DSS. The decision tree model suggested that age <71 years and adjuvant CT were associated with a better prognosis for GSM patients. The nomogram generated via the Cox proportional hazards model was developed by applying the rms package in R version 3.5.0. The C-index of internal validation for DSS prediction was 0.67 (95% confidence interval (CI), 0.63 to 0.70). The calibration curve at one year suggested that there was good consistency between the predicted DSS and the actual DSS probability. This study was the first to develop a disease-specific nomogram for predicting the prognosis of primary GSM patients after craniotomy, which can help clinicians immediately and accurately predict patient prognosis and conduct further treatment.

Racial/ethnic differences in survival for patients with gliosarcoma: an analysis of the National cancer database

PURPOSE

Gliosarcoma is characterized by the World Health Organization as a Grade IV malignant neoplasm and a variant of glioblastoma. The association of race and ethnicity with survival has been established for numerous CNS malignancies, however, no epidemiological studies have reported these findings for patients with gliosarcoma. The aim of this study was to examine differences by race and ethnicity in overall survival, 30-day mortality, 90-day mortality, and 30-day readmission.

METHODS

Data were obtained by query of the National Cancer Database (NCDB) for years 2004-2014. Patients with gliosarcoma were identified by International Classification of Diseases for Oncology, Third Edition (ICD-O-3)-Oncology morphologic code 9442/3 and topographical codes C71.0-C71.9. Differences in survival by race/ethnicity were examined using univariable and multivariable Cox proportional hazards models. Readmission and mortality outcomes were examined with univariable and multivariable logistic regression.

RESULTS

A total of 1988 patients diagnosed with gliosarcoma were identified (White Non-Hispanic n = 1,682, Black Non-Hispanic n = 165, Asian n = 40, Hispanic n = 101). There were no differences in overall survival, 30- and 90-day mortality, or 30-day readmission between the races and ethnicities examined. Median survival was 10.4 months for White Non-Hispanics (95% CI 9.8, 11.2), 10.2 months for Black Non-Hispanics (95% CI 8.6, 13.1), 9.0 months for Asian Non-Hispanics (95% CI 5.1, 18.2), and 10.6 months for Hispanics (95% CI 8.3,16.2). 7.3% of all patients examined had an unplanned readmission within 30 days.

CONCLUSION

Race/ethnicity are not associated with differences in overall survival, 30-day mortality, 90-day mortality, or 30-day readmission following surgical intervention for gliosarcoma.

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.