The prolonged use of temozolomide in glioblastoma patients

The temozolomide protocol established in 2005 increased overall survival rates in patients with glioblastoma. It defined a treatment period of 6 months, but most neuro-oncological centers prescribe more than this, reaching up to 3 years of continuous therapy. The objective of this paper was to compare duration of treatment in groups of patients and analyze the overall survival in each group. Retrospectively, 54 patients were evaluated with glioblastoma operated on from 2004 to 2009. All data were statistically analyzed using Kaplan-Meier curves, ANOVA test, multivariate logistic regression models and Pearson´s correlation. Analyses consisted on age, gender, Karnofsky Performance Scale (KPS) at diagnosis, side and localization of tumor, grade of surgical removal, period of use of temozolomide until recurrence, progression-free survival, KPS after recurrence and overall survival. According to uni and multi-varied analysis there was no statistic significant correlation between survival and age < 45, gender, KPS at diagnosis, and grade of resection. The overall survival in 6, 12, 18 and 24 months were 96.3%, 72.6%, 58.1% and 43.5% respectively. The length of treatment with temozolomide before recurrence showed strong positive correlation (r=0.66) with survival up to 15 months. Also, a correlation (r=0.64) between length of use of temozolomide and progression free-survival was found. Patients receiving treatment with temozolomide presented longer survival when compared with those not treated with it. Longer survival (p=0.04) was observed in those treated more than 12 months. This series could clearly show longer survival in patients treated with 15-cicles over patients treated with 6 or 12-cicles.