Temozolomide and seizure outcomes in a randomized clinical trial of elderly glioblastoma patients

Introduction: Tumor-related epilepsy may respond to chemotherapy. In a previously-published multi-centre randomized clinical trial of 562 elderly glioblastoma patients, temozolomide plus short-course radiotherapy conferred a survival benefit over radiotherapy alone. Seizure outcomes were not reported.

Methods: We performed an unplanned secondary analysis of this trial's data. The trial design has been previously reported. Seizures were recorded by clinicians as adverse events and by patients in quality of life questionnaires. A Chi-square test of seizure rates between the two groups (α = 0.05) and a Kaplan-Meier estimator of time-to-first self-reported seizure were planned.

Results: Almost all patients were followed until they died. In the radiotherapy alone group, 68 patients (24%) had a documented or self-reported seizure versus 83 patients (30%) in the temozolomide plus radiotherapy group, Chi-square analysis showed no difference (p = 0.15). Patients receiving radiotherapy alone tended to develop seizures earlier than those receiving temozolomide plus radiotherapy (p = 0.054). Patients with seizures had shorter overall survival than those without seizures (hazard ratio 1.24, p = 0.02).

Conclusions: This study was not powered to detect differences in seizure outcomes, but temozolomide seemed to have minimal impact on seizure control in elderly patients with glioblastoma.

Clinical trial registration: NCT00482677 2007-06-05.

Keywords: Epilepsy; Glioblastoma; Randomized controlled trial; Seizures; Temozolomide.