Nitrocamptothecin in Treating Patients With Glioblastoma Multiforme

DISEASE CHARACTERISTICS: Histologically or cytologically confirmed glioblastoma multiforme Recurrent disease confirmed by CT or MRI Bidimensionally measurable disease At least one lesion with the largest diameter at least 2 cm PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: At least 3 months Hematopoietic: Absolute neutrophil count at least 2,000/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin less than 1.5 times upper limit of normal (ULN) Alkaline phosphatase and transaminases no greater than 2.5 times ULN (no greater than 5 times ULN in case of liver metastases) Renal: Creatinine no greater than 1.7 mg/dL Cardiovascular: No history of ischemic heart disease in past 6 months Other: Not pregnant or nursing Fertile patients must use effective contraception No other prior or concurrent malignancies except cone biopsied carcinoma of the cervix or adequately treated basal or squamous cell skin carcinoma No other unstable systemic disease No active uncontrolled infection No psychological, familial, sociological, or geographical condition that would preclude study PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: At least 6 weeks since prior adjuvant chemotherapy No other prior or concurrent chemotherapy allowed Endocrine therapy: Concurrent corticosteroids allowed Stable or decreasing dose for at least 2 weeks Radiotherapy: No high dose radiotherapy, stereotactic radiosurgery, or internal radiotherapy unless recurrence is histologically confirmed At least 3 months since prior radiotherapy to the brain Surgery: No prior surgery for recurrent brain tumor except biopsy At least 3 months since prior surgery for primary brain tumor Other: No other concurrent anticancer therapy No other concurrent investigational therapy