Patterns of care and outcomes in gliosarcoma: an analysis of the National Cancer Database

Abstract

OBJECTIVE The authors compared presenting characteristics and survival for patients with gliosarcoma (GS) and glioblastoma (GBM). Additionally, they performed a survival analysis for patients who underwent GS treatments with the hypothesis that trimodality therapy (surgery followed by radiation and chemotherapy) would be superior to nontrimodality therapy (surgery alone or surgery followed by chemotherapy or radiation). METHODS Adults diagnosed with GS and GBM between the years 2004 and 2013 were queried from the National Cancer Database. Chi-square analysis was used to compare presenting characteristics. Kaplan-Meier, Cox regression, and propensity score analyses were employed for survival analyses. RESULTS In total, data from 1102 patients with GS and 36,658 patients with GBM were analyzed. Gliosarcoma had an increased rate of gross-total resection (GTR) compared with GBM (19% vs 15%, p < 0.001). Survival was not different for patients with GBM (p = 0.068) compared with those with GS. After propensity score analysis for GS, patients receiving trimodality therapy (surgery followed by radiation and chemotherapy) had improved survival (12.9 months) compared with those not receiving trimodality therapy (5.5 months). In multivariate analysis, GTR, female sex, fewer comorbidities, trimodality therapy, and age < 65 years were associated with improved survival. There was a trend toward improved survival with MGMT promoter methylation (p = 0.117). CONCLUSIONS In this large registry study, there was no difference in survival in patients with GBM compared with GS. Among GS patients, trimodality therapy significantly improved survival compared with nontrimodality therapy. Gross-total resection also improved survival, and there was a trend toward increased survival with MGMT promoter methylation in GS. The major potential confounder in this study is that patients with poor functional status may not have received aggressive radiation or chemotherapy treatments, leading to the observed outcome. This study should be considered hypothesis-generating; however, due to its rarity, conducting a clinical trial with GS patients alone may prove difficult.

Gliosarcoma: Neuroimaging and Immunohistochemical Findings

“…In patients receiving a combination of surgery, chemotherapy, and radiation therapy, survival time improved to 12.9 months from 5.5 months in patients without this combination. A trend of improved survival was also seen with MGMT promoter methylation . Both extent of resection and adjuvant chemotherapy were noted to be independent prognostic factors for increased survival in elderly GSC patients .…”

“…A trend of improved survival was also seen with MGMT promoter methylation. 30 Both extent of resection and adjuvant chemotherapy were noted to be independent prognostic factors for increased survival in elderly GSC patients. 32 A multimodality approach has been found to be overall associated with improved outcomes.…”

“…26 Though GSC has a larger rate of gross-total resection than GBM due to its margins being more well defined, overall survival time was not significantly different in a large analysis of the National Cancer Database, or in other case series. 27,30,31 In patients receiving a combination of surgery, chemotherapy, and radiation therapy, survival time improved to 12.9 months from 5.5 months in patients without this combination. A trend of improved survival was also seen with MGMT promoter methylation.…”

Clinically Important sex differences in GBM biology revealed by analysis of male and female imaging, transcriptome and survival data

“…While low-grade glioma incidence is nearly identical in males and females, malignant brain tumors in general occur more commonly in males, regardless of patient age or geographical location (6,15) (5,11). From multiple recent reports, GBM occurs with a male to female ratio of 1.6:1 (5,(8)(9)(10). More specifically, while concepts of molecular subtypes of GBM are still evolving (16), of the four originally described transcriptional subtypes of GBM, three -Mesenchymal, Proneural and Neural GBM -exhibit a 2:1 male to female incidence ratio, while Classical GBM occurs with equal incidence (17,18).…”

“…In a study analyzing more than 27,000 patients, Trifiletti et al found that female sex was associated with longer survival (10). Similarly, female patients exhibited longer survival from gliosarcoma (8), and being female was associated with better outcome in a newly developed nomogram for predicting GBM patient survival (9). Thus, the elucidation of mechanisms for sex differences in the development and treatment of GBM has a substantial potential to improve outcome for all patients by refining our understanding of disease causation and outcome.…”