Prognostic factors of local control and survival in patients irradiated for glioblastoma multiforme (GBM)

Abstract

Background/Aim: Standard treatment of glioblastoma multiforme (GBM) includes resection, longer-course radiotherapy and chemotherapy. Some patients cannot tolerate these regimens and may benefit from personalized treatments. This study aims to contribute to treatment personalization by identifying predictors of outcomes after longer-course radiotherapy. Patients and Methods: In 91 patients, number/site/diameter of lesions, Ki-67, MGMT promoter methylation, Karnofsky performance score (KPS), symptoms, gender, age and resection were evaluated for local control and survival. Results: On univariate analyses, gross resection (p=0.029) was significantly associated with improved local control. It maintained significance in the multivariate analysis [hazard ratio (HR)=1.64, p=0.025]. MGMT-methylation (p=0.004), KPS ≥80 (p=0.022) and resection (p<0.001) were significantly associated with improved survival on univariate analyses, unifocal GBM (p=0.056) showed a trend. In the multivariate analyses, MGMT-methylation (HR=3.63, p=0.009), KPS (HR=2.01, p=0.018) and resection (HR=3.29, p<0.001) were significant. Conclusion: Predictors of local control and survival were identified that may guide physicians when tailoring treatments to patients with GBM.