Prognostic significance of concomitant radiotherapy in newly diagnosed glioblastoma multiforme: a multivariate analysis of 116 patients

BACKGROUND AND OBJECTIVES: Currently, radiotherapy with concomitant and adjuvant temozolomide has become the standard treatment for glioblastoma. The purpose of this study was to report our experience with radiation plus concomitant temozolomide in 116 patients with glioblastoma multiforme (GBM) and examine the value of different prognostic factors. DESIGN AND SETTING: Retrospective analysis of 116 patients with newly diagnosed GBM, who were treated at our department between January 1994 and March 2009. PATIENTS AND METHODS: Age, gender, Karnofsky performance scale (KPS) score, a preoperative history of seizures, extent of surgery, total radiotherapy dose, and use of concomitant and adjuvant temozolomide were evaluated in uni- and multivariate analyses. Survival was determined using the Kaplan-Meier method, and differences were compared using the log rank test. Cox regression analysis was conducted to identify the independent prognostic factors. RESULTS: The median overall survival time was 9 months, and the 1- and 2-year survival rates were 41.9% and 9.6%, respectively. The univariate analysis revealed that age, KPS score, presence of seizures, radiation doses, and use of concomitant and adjuvant temozolomide were significant prognostic factors. The multivariate analysis confirmed that the age, KPS score, presence of seizures, radiation doses, and use of concomitant and adjuvant temozolomide were independent, significant prognostic factors. CONCLUSIONS: The results of our analyses demonstrate that radiation with concomitant and adjuvant temozolomide yields encouraging outcomes in patients with GBM, validating the results published in research papers. In addition, age, KPS score, presence of seizures, and radiation doses were identified as prognostic factors.