COL-3 in Treating Patients With Progressive or Recurrent Brain Tumors

DISEASE CHARACTERISTICS: Histologically proven high grade glioma that is progressive or recurrent following radiotherapy or chemotherapy Anaplastic astrocytoma Anaplastic oligodendroglioma Glioblastoma multiforme Prior low grade glioma that has progressed to high grade glioma following radiotherapy and/or chemotherapy allowed Measurable disease by MRI or CT scan PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 60-100% Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 1,500/mm^3 Platelet count at least 100,000/mm^3 Hepatic: Bilirubin normal SGOT or SGPT no greater than 2.5 times upper limit of normal Renal: Creatinine no greater than 1.5 mg/dL OR Creatinine clearance greater than 60 mL/min Cardiovascular: No myocardial infarction, stroke, or congestive heart failure within the past 3 months Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception during and for 1 month after study No serious active infection or medical illness that would preclude compliance HIV negative No history of gastrointestinal disorders that would interfere with absorption of study drug No other malignancy within the past 5 years except curatively treated carcinoma in situ of the cervix or breast, or basal cell or squamous cell skin cancer No hypersensitivity to tetracyclines or its derivatives PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent filgrastim (G-CSF) Chemotherapy: At least 4 weeks since prior chemotherapy (6 weeks since prior nitrosoureas) and recovered No more than 2 prior chemotherapy regimens Endocrine therapy: Not specified Radiotherapy: No prior large field radiotherapy (greater than 20% of total bone marrow) At least 3 months since other prior radiotherapy and recovered Surgery: No prior major upper gastrointestinal surgery At least 14 days since other prior major surgery Other: No other concurrent investigational agents No prolonged sun exposure