Abstract Details

Gliosarcoma (GSM) is a variant of glioblastoma (GBM) with sarcomatous features and lower 5-year survival rates. GSMs are divided into primary (de novo) and secondary (arising from another glial neoplasm).

Few studies describe gliosarcoma so we sought to study the demographic, pathologic, and survival characteristics of this rare cancer.

We identified patients who presented at MD Anderson Cancer Center between 2004 and 2020 with a pathology-confirmed diagnosis of gliosarcoma, using retrospective review. We performed descriptive analyses and used Kaplan-Meier survival estimates and log-rank test to compare survival between groups. We defined overall survival from the date of pathological diagnosis of gliosarcoma. For the secondary GSM, we also defined overall survival from the initial diagnosis of other neoplasm. For patients with unknown date of death, records were censored as of the date of last follow-up.

Of the 96 GSM patients, 69(71.9%) were primary and 27(28.1%) secondary. The patients in both groups were similar in age, sex, clinical characteristics, treatments, tumor characteristics, and mutations. Median age at initial diagnosis for all GSM patients was 59 years [IQR:50-65]. Molecular analysis of GSM tumor samples revealed that 47.2% were GFAP positive, 38.0% S-100 positive, and 84.1% reticulin positive. Among the tested samples 3.9% had IDH and 73.2% had TP53 mutations. The median overall survival (OS) from the pathological diagnosis of gliosarcoma for all patients was 16.8 months. Median OS from the pathological diagnosis of gliosarcoma was 17.3 months for primary and 11.1 months for secondary GSM. Median OS from the initial diagnosis of other neoplasm for secondary GSM was 30.8 months. Kaplan-Meier survival analysis showed significantly lower OS in secondary than primary GSM (log-rank p=0.01).

Our study is the largest single institution evaluation of GSM and provides insight into patterns of survival for GSM. Secondary GSM had significantly lower overall survival compared to primary.