Clinical outcome of gliosarcoma compared with glioblastoma multiforme: a clinical study in Chinese patients

Gliosarcoma (GSM) is a rare biphasic neoplasms of the central nervous system composed of a glioblastoma multiforme (GBM) admixed with a sarcomatous component. In clinical practice GSM is generally managed similarly to GBM. However, there are conflicting reports regarding their clinical aggressiveness, cell line of origin and possible prognosis compared with those of GBM. The objective of this study was to compare clinic-pathological features in GSM patients with the GBM patients during the same study period. 518 patients with GBM were treated at our hospital between 2008 and 2013, among them 51 were GSM. In this series the GSMs represented 9.8% of all GBMs and included 58.8% male with a median age of 44.7 years. The locations, all supratentorial, included temporal in 41.2%, frontal in 25.5%, parietal in 19.6%, and occipital in 13.7%. All patients underwent tumor resection followed by post-operative radiation and adjuvant chemotherapy. The O6-methylguanine-DNA methyltransferase promoter methylation studies were significantly more frequent in the GBMs than GSMs (80.1% vs. 44.7%, P < 0.001). The median progression free survival and overall survival for the patients with GSM were 8.0 and 13.0 months, respectively, as compared with 9.0 and 14.0 months in the GBM group (log rank test P = 0.001 and 0.004, respectively). The Cox proportional hazards regression model indicated that the extent of tumor resection (HR = 1.518, P = 0.009) and pathological types (HR = 0.608, P = 0.002) were the significant prognostic factors in our own series. With regard to clinical features and outcomes, GSM and GBM cannot be distinguished clinically. GSM in China may be managed similarly to GBM, with maximal safe surgical resection followed by chemo-radiotherapy. Our study adds further evidence to support GSM as a unique clinical entity with a likely worse prognosis than GBM.