DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed myeloid metaplasia with myelofibrosis (MMM), including all of the following subtypes:

  • Chronic idiopathic myelofibrosis
  • Agnogenic myeloid metaplasia
  • Post-thrombocythemic myelofibrosis
  • Post-polycythemic myelofibrosis
• Diffuse bone marrow fibrosis
• Absence of Philadelphia chromosome OR BCR-ABL rearrangement in peripheral blood cells

• Meets 1 of the following criteria:

  • Anemia (hemoglobin < 11 g/dL)
  • Palpable splenomegaly* NOTE: *Patients with palpable splenomegaly must have spleen size documented ultrasonographically AND meet standard criteria for MMM
• Morphologic evidence of advanced phase disease, including accelerated phase (10-19% blasts), or evidence of evolution to acute leukemia (≥ 20% blasts) allowed
• No known CNS disease

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2 OR
• Karnofsky 60-100%

Life expectancy

• Not specified

Hematopoietic

• See Disease Characteristics

Hepatic

• Bilirubin ≤ 2 mg/dL unless associated with hemolytic anemia as a result of predominantly unconjugated hyperbilirubinemia
• AST and ALT ≤ 3 times upper limit of normal (unless due to disease)

Renal

• Creatinine ≤ 2 mg/dL

Cardiovascular

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

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No history of allergic reaction attributed to compounds of similar chemical or biologic composition to decitabine
• No ongoing or active infection
• No other uncontrolled illness
• No psychiatric illness or social situation that would preclude study compliance

PRIOR CONCURRENT THERAPY:

Biologic therapy

• At least 2 weeks since prior growth factors (e.g., epoetin alfa, filgrastim [G-CSF], or sargramostim [GM-CSF])
• No concurrent prophylactic G-CSF or GM-CSF
• No concurrent epoetin alfa

Chemotherapy

• At least 4 weeks since prior chemotherapy (6 weeks for mitomycin or nitrosoureas)
• No prior decitabine
• No other concurrent chemotherapy

Endocrine therapy

• At least 4 weeks since prior androgenic steroids
• No concurrent androgenic steroids

Radiotherapy

• Prior splenic irradiation allowed
• At least 4 weeks since prior radiotherapy
• No concurrent radiotherapy

Surgery

• Not specified

Other

• Recovered from all prior therapy
• At least 4 weeks since other prior therapy
• No other concurrent investigational agents
• No other concurrent antineoplastic agents
• No concurrent combination antiretroviral therapy for HIV-positive patients