Improved Median Survival for Glioblastoma Multiforme Following Introduction of Adjuvant Temozolomide Chemotherapy

Abstract

The use of adjuvant temozolomide (TMZ) in patients managed with surgery and adjuvant radiation therapy (RT) for glioblastoma multiforme (GBM) has been demonstrated to improve median and 2-year survival in a recent large international multicentre study. To confirm this result in routine clinical practice, an audit of the management and outcome of patients with GBM at The Cancer Institute Radiation Oncology was performed. All patients with GBM managed radically at The Cancer Institute Radiation Oncology from May 2002 to 2006 were entered into a prospective database. Patient, tumour and treatment factors were analysed for association with the outcome of median survival (MS). Survival was calculated using the Kaplan-Meier technique and correlation was assessed using Cox proportional hazards regression. Forty-one patients with GBM were managed with radical intent over the 4- year period. The median age was 54 years and 66% were Eastern Cooperative Oncology Group (ECOG) 0-1 performance status. Macroscopic, subtotal and biopsy alone procedures were performed in 61%, 29% and 10% of patients, respectively. The median time from surgery to RT was 26 days. Adjuvant TMZ was used in 44% of patients (n = 18). The MS of the total group was 13.6 months, with a 24% 2-year overall survival. The use of TMZ was associated with improved MS (19.6 versus 12.8 months; P = 0.035) and improved 2-year survival (43% versus 0%). A requirement of dexamethasone dose greater than 4 mg at the end of RT (P = 0.012) was associated with worse survival, but there was no association of MS with age, ECOG, tumour size or extent of surgery. The median and 2-year survival outcomes are comparable to the results of the European Multicentre Study and justify the continued use of TMZ in routine clinical practice.