Temozolomide Compared to Procarbazine, Lomustine, and Vincristine in Treating Patients With Recurrent Malignant Glioma

DISEASE CHARACTERISTICS: * Histologically confirmed anaplastic astrocytoma, glioblastoma multiforme, or gliosarcoma * WHO grade III or IV at diagnosis or relapse * Must have undergone primary therapy including radiotherapy * Must be in first recurrence confirmed by CT scan or MRI * Evaluable disease by CT scan or MRI PATIENT CHARACTERISTICS: Age * 18 and over Performance status * WHO 0-3 Life expectancy * At least 1 month Hematopoietic * Absolute neutrophil count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 Hepatic * Total and direct bilirubin less than 1.5 times upper limit of normal (ULN) * SGOT or SGPT less than 3 times ULN * Alkaline phosphatase less than 2 times ULN Renal * BUN less than 1.5 times ULN * Creatinine less than 1.5 times ULN Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No other concurrent serious illness * Considered fit to receive chemotherapy PRIOR CONCURRENT THERAPY: Biologic therapy * Not specified Chemotherapy * No prior chemotherapy for glioma Endocrine therapy * Not specified Radiotherapy * See Disease Characteristics * At least 2 months since prior radiotherapy * No prior radiosurgery, interstitial radiotherapy, or brachytherapy for glioma Surgery * Prior debulking surgery for recurrent disease allowed