Temozolomide in Treating Patients With Brain Metastases

DISEASE CHARACTERISTICS: * Metastatic lesions to the brain * Must not require immediate radiotherapy * If received prior radiotherapy, must have progressive disease * Evaluable disease by CT scan or MRI * Neurologically stable PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * Karnofsky 70-100% Life expectancy: * More than 12 weeks Hematopoietic: * Absolute neutrophil count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 * Hemoglobin at least 10 g/dL Hepatic: * Bilirubin less than 1.5 times upper limit of normal (ULN) * SGOT or SGPT less than 2.5 times ULN * Alkaline phosphatase less than 2 times ULN Renal: * Blood urea nitrogen 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 nonmalignant systemic disease * No acute infection requiring treatment with IV antibiotics * HIV negative * No frequent vomiting or medical condition that would preclude oral medication administration (e.g., partial bowel obstruction, inability to swallow) PRIOR CONCURRENT THERAPY: Biologic therapy: * No concurrent hematopoietic growth factors, including epoetin alfa * No other concurrent biologic therapy Chemotherapy: * At least 4 weeks since prior chemotherapy, unless evidence of disease progression * No other concurrent chemotherapy Endocrine therapy: * Concurrent corticosteroids allowed if nonincreasing dose for at least 1 week prior to study Radiotherapy: * See Disease Characteristics * At least 4 weeks since prior radiotherapy to the brain, unless evidence of disease progression * No concurrent radiotherapy Surgery: * At least 3 weeks since prior surgery, unless evidence of disease progression, and recovered Other: * No other concurrent investigational drugs