Clinical and epidemiological characteristics of pediatric gliosarcomas

Gliosarcoma (GS) is a glioblastoma with a sarcomatous component that is presumed to be a metaplastic differentiation of glioma cells. We studied the clinical relevance of this histological glioblastoma subentity within the pediatric population. We obtained patient data from the German HIT-GBM database, which contains clinical data for more than 600 pediatric patients with centrally reviewed high-grade gliomas. By applying defined inclusion criteria (diagnosis of GS proven by central neuropathological review; patient age 0 to 21 years), four patients were identified. In addition, after a review of the English medical scientific literature, 19 additional cases were found. The relative frequency of GS in the German HIT-GBM database was only 1.9%. In the whole series of 23 pediatric GS patients, including previously reported cases, the male-to-female-ratio was 1.2:1. GS was found in all pediatric age groups with a median age of 11 years, but there was an unexpectedly high accumulation in infants (6 of 23\3 years of age, 26%). GS showed a strong predilection of the cerebral hemispheres (22 out of 23 cases). Increased intracranial pressure was the leading symptom of a short clinical history with a median duration of 0.7 month. Interestingly, six patients (26%) were reported with a history of cranial radiotherapy prior to GS diagnosis. In 60% of the GS patients in our series, gross total resection was achieved. Median overall (OS) and event-free survivals (EFS) of the total cohort were 12.1 and 9.8 months, respectively. In conclusion, GS is a very rare tumor entity in children. Literature review suggests a relatively higher incidence in infants and in patients with a previous history of radiotherapy.