DISEASE CHARACTERISTICS:

• Histologically confirmed meningioma

  • Benign, malignant, or atypical disease
  • Neurofibromatosis (NF) type 1 or 2 allowed
  • Hemangiopericytoma allowed
• Unequivocal evidence of tumor recurrence or progression by MRI or CT scan (on steroid dosage that is stable for at least 5 days)
• Evaluable residual disease by MRI or CT scan if previously treated with surgical resection for recurrent or progressive disease
• Newly diagnosed recurrent disease that requires surgical debulking allowed

• Prior standard external-beam radiotherapy, interstitial brachytherapy, or gamma-knife radiosurgery allowed provided disease has progressed since completion of therapy

  • Patients who have had prior brachytherapy or stereotactic radiosurgery must have confirmation of true progressive disease rather than radiation necrosis based upon positron-emission tomography or thallium scanning, magnetic resonance spectroscopy, or surgical documentation
• Patients with a history of NF may have other stable CNS tumors (e.g., schwannoma, acoustic neuroma, or ependymoma) provided those lesions have been stable in size for the past 6 months

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• Karnofsky 60-100%

Life expectancy

• More than 8 weeks

Hematopoietic

• Absolute neutrophil count at least 2,000/mm^3
• Platelet count at least 120,000/mm^3
• Hemoglobin at least 10 g/dL (transfusions allowed)
• No bleeding disorders

Hepatic

• Bilirubin less than 2 times upper limit of normal (ULN)
• SGOT less than 2 times ULN
• PT, PTT, and INR no greater than 1.5 times ULN

Renal

• Creatinine less than 1.5 mg/dL AND/OR
• Creatinine clearance at least 60 mL/min

Cardiovascular

• No deep venous or arterial thrombosis within the past 6 weeks

Pulmonary

• No pulmonary embolism within the past 6 weeks

Other

• No serious active infection
• No prior intracranial hemorrhage
• No concurrent disease that would obscure toxicity or dangerously alter drug metabolism
• No other malignancy except nonmelanoma skin cancer or carcinoma in situ of the cervix unless the patient is in complete remission and off all therapy for that disease for at least 3 years
• No other significant medical illness that would preclude study participation
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective barrier contraception during and for 3 months after study participation

PRIOR CONCURRENT THERAPY:

Biologic therapy

• At least 1 week since prior interferon or thalidomide
• No concurrent immunotherapy
• Concurrent epoetin alfa allowed

Chemotherapy

• At least 4 weeks since prior cytotoxic chemotherapy
• At least 2 weeks since prior vincristine
• At least 6 weeks since prior nitrosoureas
• At least 3 weeks since prior hydroxyurea or procarbazine
• No concurrent chemotherapy

Endocrine therapy

• See Disease Characteristics
• At least 1 week since prior tamoxifen
• No concurrent hormonal therapy

Radiotherapy

• See Disease Characteristics
• At least 4 weeks since prior radiotherapy
• No concurrent radiotherapy

Surgery

• See Disease Characteristics
• Recovered from prior surgery

Other

• Recovered from all prior therapy
• At least 1 week since prior noncytotoxic therapy (e.g., isotretinoin) except radiosensitizers
• At least 2 weeks since prior drugs that affect hepatic metabolism
• At least 4 weeks since prior investigational agents
• No concurrent warfarin (heparin or low-molecular weight heparin allowed)
• No other concurrent investigational agents
• No concurrent acetaminophen of more than 500 mg/day
• No other concurrent anticancer therapy