DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed surgically incurable solid tumor or hematologic malignancy for which no standard or palliative therapy exists or is no longer effective

  • All tumor types are eligible, including:

    • Chronic myelogenous leukemia or other Philadelphia chromosome-positive leukemia OR
    • Gastrointestinal stromal tumors
• Patients with gliomas that require corticosteroids or anticonvulsants must be on a stable dose and seizure-free for 1 month
• No unstable or untreated (non-irradiated) brain metastases

PATIENT CHARACTERISTICS:

Age:

• Over 15 (Patients 15 -18 years are eligible only if refractory disease and no alternative therapy options exist)

Performance status:

• ECOG 0-2 OR
• Karnofsky 60-100%

Life expectancy:

• More than 3 months

Hematopoietic:

• WBC at least 3,000/mm^3
• Absolute neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3
• No active hemolysis

Hepatic:

• See Surgery
• No evidence of biliary sepsis

Renal:

• Creatinine normal OR
• Creatinine clearance at least 60 mL/min

Cardiovascular:

• No symptomatic congestive heart failure
• No unstable angina pectoris
• No cardiac arrhythmia

Other:

• Able to swallow pills
• No other uncontrolled concurrent illness that would preclude study participation
• No ongoing or active infection
• No uncontrolled diarrhea
• No psychiatric illness or social situation that would preclude study compliance
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective barrier contraception during and for 6 months after study completion

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• At least 24 hours since prior colony-stimulating factors
• No concurrent colony-stimulating factors

Chemotherapy:

• At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered

Endocrine therapy:

• See Disease Characteristics

Radiotherapy:

• See Disease Characteristics
• At least 4 weeks since prior radiotherapy and recovered

Surgery:

• See Disease Characteristics
• At least 10 days since prior placement of shunt for treatment of biliary obstruction
• At least 14 days since prior major surgery
• No prior solid organ transplantation

Other:

• No other concurrent investigational agents
• No concurrent therapeutic doses of warfarin for anticoagulation
• No other concurrent investigational or commercial agents or therapies for treatment of this disease
• No concurrent combination antiretroviral therapy for HIV-positive patients
• No concurrent acetaminophen of more than 4,000 mg/day