Inclusion Criteria

DISEASE CHARACTERISTICS:

- Part I:

- Histologically confirmed, newly diagnosed glioblastoma multiforme or anaplastic
astrocytoma (closed to accrual 12/19/2000)

- Parts I and II:

- Histologically confirmed astrocytic, oligodendroglial, or mixed glial tumor

- Grade III or higher

- Recurrent or progressive after radiotherapy

- Evaluable residual disease by contrast-enhanced MRI or CT scan

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- Karnofsky 60-100%

Life expectancy:

- Not specified

Hematopoietic:

- Granulocyte count at least 1,500/mm3

- Platelet count at least 100,000/mm3

Hepatic:

- SGOT no greater than 2.5 times upper limit of normal

- Bilirubin normal

Renal:

- Creatinine no greater than 1.5 mg/dL OR

- Creatinine clearance greater than 60 mL/min

- BUN no greater than 25 mg/dL

Other:

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception during and for 2 months after study

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- At least 6 weeks since prior biologic therapy and recovered

Chemotherapy:

- At least 2 weeks since prior chemotherapy (including but not limited to topotecan)
and recovered

- Patients in trials with one of the following treatment combinations are allowed
to enroll 6 weeks after receiving carmustine (BCNU):

- BCNU on day 1

- BCNU on day 1 and topotecan on days 1, 8, 15, 22, 29, and 36

- BCNU on day 1 and irinotecan on days 1, 8, 15, and 22

Endocrine therapy:

- Patients on corticosteroids must be on a stable dose for at least 2 weeks before
study

- At least 6 weeks since other prior endocrine therapy and recovered

Radiotherapy:

- See Disease Characteristics

- At least 6 weeks since prior radiotherapy and recovered

Surgery:

- Not specified