DISEASE CHARACTERISTICS:

• Histologically confirmed solid tumor

  • Refractory disease
• Not amenable to conventional surgery, chemotherapy, or radiotherapy
• No known brain metastasis

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2 OR
• Karnofsky 60-100%

Life expectancy

• At least 12 weeks

Hematopoietic

• Absolute neutrophil count ≥ 1,500/mm^3
• Platelet count ≥ 100,000/mm^3
• Hemoglobin ≥ 9.0 g/dL

Hepatic

• AST < 2.5 times upper limit of normal
• Bilirubin < 1.5 mg/dL

Renal

• Creatinine < 1.5 mg/dL OR
• Creatinine clearance ≥ 60 mL/min

Cardiovascular

• No symptomatic congestive heart failure
• No unstable angina pectoris
• No cardiac arrhythmia
• No New York Heart Association class III or IV heart disease

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No concurrent uncontrolled illness
• No active or ongoing infection
• No psychiatric illness or social situation that would preclude study compliance

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• At least 3 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered

Endocrine therapy

• Not specified

Radiotherapy

• At least 4 weeks since prior large-field radiotherapy and recovered

Surgery

• Not specified

Other

• At least 4 weeks since prior investigational agents
• At least 3 weeks since prior anticancer therapy and recovered
• No concurrent combination antiretroviral therapy for HIV-positive patients
• No other concurrent investigational agents or therapies
• No other concurrent anticancer agents or therapies