Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed myelodysplastic syndrome (MDS) indicating
one of the following:

- Refractory anemia (RA)

- Primary refractory leukopenia or thrombocytopenia with MDS morphology

- RA with excess blasts (RAEB)

- RA with ringed sideroblasts (RARS)

- Chronic myelomonocytic leukemia

- RAEB in transformation

- RA or RARS must have at least one of the following:

- Absolute neutrophil count less than 1,000/mm^3

- Untransfused hemoglobin less than 8 g/dL

- Platelet count less than 20,000/mm^3

- Anemia

- Thrombocytopenia requiring transfusion

- High risk chromosomal abnormalities

- Any stage of MDS allowed including:

- Previously untreated MDS

- Refractory MDS allowed if failure to achieve remission following prior intensive
chemotherapy of at least 1 month ago

- Relapsed, refractory, or untreated acute myeloid leukemia (AML) with the following:

- WBC less than 30,000/mm^3

- Stable for at least 2 weeks

- Unlikely to require cytotoxic therapy during study

- Untreated AML with poor risk factors for response to standard therapy including:

- Greater than 60 years old

- AML occurs in setting of antecedent hematologic disorder

- High risk chromosomes (e.g., abnormalities of chromosome 5 or 7 or complex
cytogenetic abnormalities)

- Medical conditions that preclude cytotoxic chemotherapy as primary therapy

- Refusal of cytotoxic chemotherapy allowed

- No clinical evidence of CNS leukostasis or CNS leukemia

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- Zubrod 0-2

Life expectancy:

- Not specified

Hematopoietic:

- See Disease Characteristics

- Hemoglobin at least 8 g/dL (transfusion allowed)

Hepatic:

- Bilirubin less than 2.0 mg/dL (unless due to hemolysis or Gilbert's disease)

Renal:

- Creatinine less than 2.0 mg/dL

Cardiovascular:

- No disseminated intravascular coagulation

Pulmonary:

- No pulmonary leukostasis

Other:

- No active infection

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception 2 weeks prior, during and 3 months
after study

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- At least 3 weeks since prior biologic therapy including colony stimulating factors
and recovered

Chemotherapy:

- See Disease Characteristics

- At least 3 weeks since prior chemotherapy and recovered

Endocrine therapy:

- At least 3 weeks since prior hormonal therapy and recovered

Radiotherapy:

- At least 3 weeks since prior radiotherapy and recovered

Surgery:

- Not specified