Gefitinib Plus Temozolomide in Treating Patients With Malignant Primary Glioma

DISEASE CHARACTERISTICS: * Histologically confirmed malignant primary glioma * Glioblastoma multiforme * Anaplastic astrocytoma * Anaplastic oligodendroglioma * Anaplastic mixed oligoastrocytoma * Malignant astrocytoma not otherwise specified * Stable or progressive disease * Progressive disease after interstitial brachytherapy or stereotactic radiosurgery must be confirmed by positron emission tomography or thallium scan, magnetic resonance spectroscopy, or surgical biopsy * Prior treatment for no more than 3 prior relapses allowed PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * Karnofsky 60-100% Life expectancy: * More than 8 weeks Hematopoietic: * WBC greater than 3,000/mm\^3 * Absolute neutrophil count greater than 1,500/mm\^3 * Platelet count greater than 120,000/mm\^3 * Hemoglobin greater than 10 g/dL (transfusion allowed) Hepatic: * Bilirubin less than 1.5 times upper limit of normal (ULN) * SGOT less than 1.5 times ULN Renal: * Creatinine less than 1.5 mg/dL OR * Creatinine clearance greater than 60 mL/min Other: * Not pregnant * Negative pregnancy test * Fertile patients must use effective contraception * No active infection * No other concurrent significant medical illness that would preclude study participation * No significant gastrointestinal risk factors (e.g., active ulcerative colitis) within the past 6 months * No other malignancy within the past 3 years except non-melanoma skin cancer or carcinoma in situ of the cervix PRIOR CONCURRENT THERAPY: Biologic therapy: * At least 1 week since prior interferon * No concurrent filgrastim (G-CSF) during the first course of study therapy Chemotherapy: * At least 2 weeks since prior vincristine * At least 3 weeks since prior procarbazine * At least 6 weeks since prior nitrosoureas * Prior or concurrent temozolomide allowed if there is no evidence of progression while receiving therapy Endocrine therapy: * At least 1 week since prior tamoxifen * Must be on a stable dose of corticosteroids for at least 5 days Radiotherapy: * See Disease Characteristics * At least 3 weeks since prior radiotherapy Surgery: * See Disease Characteristics * At least 1 week since prior surgical resection Other: * Recovered from all prior therapy * No prior gefitinib * At least 1 week since prior non-cytotoxic agents except radiosensitizers * At least 4 weeks since prior cytotoxic therapy * At least 4 weeks since prior investigational agents * At least 3 years since prior therapy for other malignancy * Concurrent therapeutic agents allowed at stable dosage * Concurrent enzyme-inducing anti-epileptic drugs allowed if continued during study participation