Outcome and prognostic factors in cerebellar glioblastoma multiforme in adults: a retrospective study from the Rare Cancer Network.

Abstract

The aim of this study was to assess the outcome in patients with cerebellar glioblastoma (GBM) treated in 15 institutions of the Rare Cancer Network. Data from a series of 45 adult patients with cerebellar GBM were collected in a retrospective multicenter study. Median age was 50.3 years. Brainstem invasion was observed in 9 (20%) patients. Radiotherapy (RT) was administered to 36 patients (with concomitant chemotherapy, 7 patients). Adjuvant chemotherapy after RT was administered in 8 patients. Median RT dose was 59.4 Gy. Median follow-up was 7.2 months (range, 3.4-39.0). The 1-year and 2-year actuarial overall survival rate was 37.8% and 14.7%, respectively, and was significantly influenced by salvage treatment (p = 0.048), tumor volume (p = 0.044), extent of neurosurgical resection (p = 0.019), brainstem invasion (p = 0.0013), additional treatment after surgery (p < 0.001), and completion of the initial treatment (p < 0.001) on univariate analysis. All patients experienced local progression: 8 and 22 had progression with and without a distant failure, respectively. The 1- and 2-year actuarial progression free survival was 25% and 10.7%, respectively, and was significantly influenced by brainstem invasion (p = 0.002), additional treatment after surgery (p = 0.0016), and completion of the initial treatment (p < 0.001). On multivariate analysis, survival was negatively influenced by the extent of surgery (p = 0.03) and brainstem invasion (p = 0.02). In this multicenter retrospective study, the observed pattern of failure was local in all cases, but approximately 1 patient of 4 presented with an extracerebellar component. Brainstem invasion was observed in a substantial number of patients and was an adverse prognostic factor.