RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die.

PURPOSE: Phase II trial to study the effectiveness of irinotecan in treating patients who have recurrent glioma.

OBJECTIVES: I. Determine the efficacy of irinotecan in the treatment of patients with recurrent glioma. II. Assess the toxicities of irinotecan in these patients. III. Correlate the pharmacological parameters with toxicity and response to therapy.

OUTLINE: This is a two arm study. Patients are stratified according to prior nitrosourea administration. Patients are assigned to 1 of 2 arms, with only 1 arm being open at any time. Patients assigned to arm I receive irinotecan IV over 90 minutes on days 1, 8, 15, and 22. This is followed by a 2 week rest and continues for a maximum of 6 courses. Patients assigned to arm II receive irinotecan on day 1 every 3 weeks for up to 12 courses. Patients in both arms who received prior nitrosoureas receive reduced starting doses of irinotecan. The dosages may be increased once per patient after the first course if toxic effects are acceptable. Arm I closed as of 10/98, Arm II open as of 10/98. Patients are followed every 3 months for the first year, every 6 months for the next 4 years, then annually until death.

DISEASE CHARACTERISTICS: Histologically proven primary brain glioma Astrocytoma Gliosarcoma Oligodendroglioma Oligoastrocytoma Tumor progression by CT scan or MRI following radiotherapy Measurable or evaluable disease

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 1500/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 9 g/dL Hepatic: Bilirubin no greater than 1.5 mg/dL AST no greater than 3 times upper limit of normal No prior Gilbert's syndrome Renal: Creatinine no greater than 2.0 mg/dL Cardiovascular: No history of myocardial infarction within 6 months No congestive heart failure requiring therapy Other: No concurrent active second malignancy No uncontrolled infection No other severe concurrent disease Not pregnant or lactating Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No more than 1 prior adjuvant chemotherapy regimen and 1 for recurrence (Gliadel is considered 1 regimen) At least 4 weeks since prior chemotherapy At least 6 weeks since prior nitrosoureas No prior irinotecan, topotecan, or aminocamptothecin Endocrine therapy: At least 2 weeks on fixed dose of corticosteroids (or no corticosteroids) prior to baseline scan Radiotherapy: At least 8 weeks since prior radiotherapy Surgery: No surgical resection between last radiotherapy or chemotherapy and study therapy, unless unequivocal tumor growth since surgery