DISEASE CHARACTERISTICS:

• Histologically confirmed solid tumor at original diagnosis that has failed standard therapy or for which no standard therapy exists

  • Patients must have a disease for which there is no known curative potential

• Patients must meet the following criteria for bone marrow function:

  • Status post stem cell transplantation (SCT)
  • Absolute neutrophil count at least 1,500/mm^3
  • Platelet count at least 100,000/mm^3 (transfusion independent)
  • Hemoglobin at least 8.0 g/dL (RBC transfusions allowed)
• No lymphomas
• No CNS tumors or known metastatic disease to the brain or spinal cord

PATIENT CHARACTERISTICS:

Age:

• 1 to 21

Performance status:

• Karnofsky 50-100% (age 11 to 21)
• Lansky 50-100% (age 1 to 10)

Life expectancy:

• At least 8 weeks

Hematopoietic:

• See Disease Characteristics

Hepatic:

• Bilirubin no greater than 1.5 times upper limit of normal (ULN)
• ALT no greater than 3 times ULN
• No significant hepatic dysfunction

Renal:

• Creatinine clearance or radioisotope glomerular filtration rate at least 70 mL/min OR

• Creatinine, based on age, as follows:

  • Age 1 to 5: no greater than 0.8 mg/dL
  • Age 6 to 10: no greater than 1.0 mg/dL
  • Age 11 to 15: no greater than 1.2 mg/dL
  • Age 16 to 21: no greater than 1.5 mg/dL
• No significant renal dysfunction

Cardiovascular:

• Shortening fraction at least 28% by echocardiogram OR
• Ejection fraction at least 45% by MUGA

Pulmonary:

• No significant pulmonary dysfunction

Other:

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No serious uncontrolled infections
• No other end-organ dysfunction that would preclude study entry
• No other clinically significant systemic illness

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• See Disease Characteristics
• Recovered from prior immunotherapy
• At least 1 week since prior growth factors or other biologic agents
• At least 6 months since prior autologous SCT
• At least 6 months since prior allogeneic bone marrow transplantation and recovered with no evidence of graft-versus-host disease
• No concurrent immunomodulating agents
• No concurrent prophylactic growth factors during the first course of the study
• No concurrent immunotherapy or other biologic therapy

Chemotherapy:

• Recovered from prior chemotherapy
• At least 2 weeks since prior myelosuppressive chemotherapy (6 weeks for nitrosoureas)
• No prior life-time cumulative doxorubicin dose of more than 450 mg/m^2 or equivalent
• No other concurrent chemotherapy

Endocrine therapy:

• Concurrent chronic steroids allowed

Radiotherapy:

• Recovered from prior radiotherapy
• More than 2 weeks since prior localized palliative radiotherapy (small port)
• More than 6 months since prior substantial radiotherapy to bone marrow (craniospinal radiotherapy, total body irradiation, or hemi-pelvic radiotherapy)
• No concurrent radiotherapy

Surgery:

• Not specified

Other:

• Concurrent chronic medications (e.g., narcotics or antiepileptics) allowed
• No other concurrent investigational agents
• No other concurrent cancer therapy