DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed solid tumor or lymphoma for which standard curative or palliative measures do not exist or are no longer effective

  • Pathological confirmation of diagnosis not required in patients with liver mass, raised alpha-fetoprotein levels (at least 500 ng/mL), and positive serology for hepatitis consistent with a diagnosis of hepatocellular carcinoma
  • Any solid tumor or lymphoma tumor type eligible
  • Must have had thoracic and upper abdominal CT scan, including entire liver and adrenals, within 28 days before study entry

• Patients with glioma or brain metastases must be on a stable dose of corticosteroids and be seizure-free for the past month

  • Prior whole brain or gamma knife radiotherapy required for known brain metastases
  • No unstable or untreated (non-irradiated) brain metastases

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• Zubrod 0-2

Life expectancy

• Not specified

Hematopoietic

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

Hepatic

• See Disease Characteristics
• Patients with biliary obstruction for which a shunt has been placed are allowed if shunt is in place for at least 10 days and liver function is stable
• Abnormal liver function (bilirubin and SGOT) allowed regardless of cause (metastases or other causes)
• No evidence of biliary sepsis

Renal

• Creatinine no greater than 1.5 mg/dL

Cardiovascular

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

Other

• No concurrent uncontrolled illness
• No ongoing or active infection
• No uncontrolled diarrhea
• No peripheral neuropathy grade II or greater
• No psychiatric illness or social situation that would preclude study compliance
• HIV negative
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective barrier contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy

• No concurrent immunotherapy for malignancy

Chemotherapy

• More than 2 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin)
• No other concurrent chemotherapy for malignancy

Endocrine therapy

• See Disease Characteristics
• No concurrent oral contraceptives

• No concurrent hormone therapy for malignancy

  • Concurrent luteinizing hormone-releasing hormone agonists allowed

Radiotherapy

• See Disease Characteristics
• More than 4 weeks since prior radiotherapy and recovered
• No concurrent radiotherapy for malignancy

Surgery

• More than 2 weeks since prior major surgery

Other

• Recovered from prior therapy
• No concurrent medications that are known to be inhibitors of CYP3A4