DISEASE CHARACTERISTICS:

• Diagnosis of 1 of the following:

  • Histologically confirmed solid tumor

    • No brain tumors

  • Myelodysplastic syndromes (MDS)

    • No refractory anemia with excess blasts in transformation or other forms of acute myeloid leukemia (AML)
    • No FAB diagnosis of refractory anemia with excess blasts in transition and other forms of AML
    • Newly diagnosed MDS with chromosome 5q abnormalities
• Relapsed or refractory disease including relapse after stem cell transplantation
• Measurable or evaluable disease (solid tumor patients only)
• No known curative or life-prolonging therapy exists
• No bone marrow involvement by tumor (solid tumor patients only)
• No CNS tumors

PATIENT CHARACTERISTICS:

Age

• 1 to 21

Performance status

• Karnofsky 50-100% (for patients > 10 years of age)
• Lansky 50-100% (for patients ≤ 10 years of age)

Life expectancy

• Not specified

Hematopoietic

• Absolute neutrophil count ≥ 1,000/mm^3 (for patients with solid tumors)

• Platelet count ≥ 100,000/mm^3 (30,000 for patients with MDS)

  • Only patients with MDS may receive transfusions to support platelet counts
• Hemoglobin ≥ 8.0 g/dL (transfusions allowed)

Hepatic

• Bilirubin ≤ 1.5 times upper limit of normal (ULN)
• ALT ≤ 110*
• Albumin ≥ 2 g/dL NOTE: *For purposes of this study, the ULN for SGPT is 45 U/L

Renal

• Creatinine clearance OR radioisotope glomerular filtration rate ≥ 70 mL/min OR

• Creatinine based on age as follows:

  • Creatinine ≤ 0.8 mg/dL (for patients ≤ 5 years of age)
  • Creatinine ≤ 1 mg/dL (for patients 6 to 10 years of age)
  • Creatinine ≤ 1.2 mg/dL (for patients 11 to 15 years of age)
  • Creatinine ≤ 1.5 mg/dL (for patients over 15 years of age)

Cardiovascular

• No parent or sibling with a known history of venous thrombosis before the age of 50 OR arterial thrombosis before the age of 40
• No thromboembolic event except catheter-related thrombosis

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective double-method contraception 4 weeks before, during, and for ≥ 4 weeks after completion of study treatment
• Body surface area ≥ 0.4m^2
• No uncontrolled infection
• No active graft-vs-host disease from prior stem cell transplant or rescue

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Recovered from prior immunotherapy
• At least 1 week since prior biologic agents
• At least 1 week since prior hematologic growth factors (2 weeks for pegfilgrastim)
• At least 3 months since prior stem cell transplant or rescue (without total body irradiation [TBI])
• Prior thalidomide allowed
• No other concurrent immunotherapy
• No other concurrent biologic therapy

Chemotherapy

• More than 3 weeks since prior myelosuppressive chemotherapy (6 weeks for nitrosoureas) and recovered
• No concurrent chemotherapy

Endocrine therapy

• Concurrent dexamethasone allowed provided the dose has been either decreasing or stable for the past 7 days

Radiotherapy

• See Biologic therapy
• Recovered from prior radiotherapy
• At least 2 weeks since prior local palliative (small port) radiotherapy
• At least 6 months since prior TBI, craniospinal radiotherapy, or radiotherapy to ≥ 50% of the pelvis
• At least 6 weeks since other prior substantial bone marrow radiotherapy
• No concurrent radiotherapy

Surgery

• Not specified

Other

• No other concurrent investigational drugs or agents
• No other concurrent anticancer agents