Low-Dose Decitabine Compared With Standard Supportive Care in Treating Older Patients With Myelodysplastic Syndrome

DISEASE CHARACTERISTICS: * Diagnosis of primary or secondary myelodysplastic syndromes (MDS) * Any FAB or WHO criteria cellular type allowed * Bone marrow blast count on aspiration or biopsy of 1 of the following: * No more than 10% with poor cytogenetic risk factors (defined as any numerical or structural abnormality of chromosome 7 and/or complex abnormalities) * 11-20% * 21-30% for patients with acute myeloid leukemia (AML) secondary to MDS (i.e., refractory anemia with excess blasts in transformation by FAB classification) * Patients who failed the cytogenetic exam are allowed provided bone marrow blasts are at least 5% and/or 2-3 cytopenias are present * No rapid progression towards full-blown AML * No blast crisis of chronic myeloid leukemia * No t(8;21) alone or in combination with other abnormalities * Ineligible for intensive chemotherapy (e.g., cytarabine or an anthracycline) PATIENT CHARACTERISTICS: Age * 60 and over Performance status * WHO 0-2 Life expectancy * Not specified Hematopoietic * See Disease Characteristics Hepatic * Bilirubin less than 1.5 times upper limit of normal (ULN) * Hepatitis B surface antigen negative Renal * Creatinine less than 1.5 times ULN Cardiovascular * No severe cardiovascular disease * No arrhythmias requiring chronic treatment * No congestive heart failure * No New York Heart Association class III or IV heart disease * No symptomatic ischemic heart disease Other * HIV negative * No active uncontrolled infection * No other malignancy within the past 3 years except basal cell or squamous cell skin cancer or carcinoma in situ of the cervix within the past 2 years * No prior or concurrent evidence of CNS or psychiatric disorders requiring hospitalization * No psychological, familial, sociological, or geographical condition that would preclude study PRIOR CONCURRENT THERAPY: Biologic therapy * More than 6 weeks since prior growth factors for primary MDS * No concurrent antiangiogenic drugs (e.g., thalidomide) * No concurrent interleukin, interferon, or anti-thymocyte globulin Chemotherapy * See Disease Characteristics * More than 6 weeks since prior hydroxyurea for primary MDS * No other prior chemotherapy for MDS or AML * Prior chemotherapy for solid tumors or lymphoma (resulting in secondary MDS) allowed Endocrine therapy * No concurrent steroids (except as inhalation therapy) Radiotherapy * Prior radiotherapy for solid tumors or lymphoma (resulting in secondary MDS) allowed Surgery * Not specified Other * More than 6 weeks since prior immunosuppressive agents for primary MDS * No concurrent amifostine * No concurrent cyclosporine * No other concurrent experimental therapies