DISEASE CHARACTERISTICS:

• Histologically confirmed incurable anaplastic astrocytoma that has progressed, recurred, or persisted after completion of standard therapy (including radiation therapy)
• Measurable disease by MRI or CT scan
• Tumor must be at least 5 mm
• Must have received prior standard therapy (i.e., radiation therapy, chemotherapy, immunotherapy, or cytodifferentiating agent)

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• Karnofsky 60-100%

Life expectancy:

• At least 2 months

Hematopoietic:

• WBC at least 2000/mm^3
• Platelet count at least 50,000/mm^3

Hepatic:

• Bilirubin no greater than 2.5 mg/dL
• SGOT and SGPT no greater than 5 times upper limit of normal
• No hepatic failure

Renal:

• Creatinine no greater than 2.5 mg/dL
• No history of renal conditions that contraindicate high dosages of sodium

Cardiovascular:

• No uncontrolled hypertension
• No history of congestive heart failure
• No history of other cardiovascular conditions that contraindicate high dosages of sodium

Pulmonary:

• No serious lung disease such as severe chronic obstructive pulmonary disease

Other:

• Not pregnant or nursing
• Fertile patients must use effective contraception during and for 4 weeks after study
• No active infection
• No other serious concurrent disease

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• At least 4 weeks since prior immunotherapy and recovered
• No concurrent immunomodulating agents

Chemotherapy:

• At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas) and recovered
• No concurrent antineoplastic agents

Endocrine therapy:

• Concurrent corticosteroids allowed

Radiotherapy:

• At least 8 weeks since prior radiotherapy and recovered

Surgery:

• Fully recovered from any prior surgery

Other:

• Prior cytodifferentiating agent allowed
• No prior antineoplaston therapy