OUTLINE: Patients are stratified according to ECOG performance status (0-1 vs 2), prior surgery (yes vs no), prior radiotherapy (yes vs no), and prior chemotherapy regimens (0 vs 1 vs 2). Patients receive oral temozolomide every 12 hours for 5 days. Courses repeat every 4 weeks for at least 18 months in the absence of unacceptable toxicity or disease progression. Patients are followed every 3 months for the first 18 months, every 6 months for the next 18 months, and then annually thereafter until death.