Phenylbutyrate and Tretinoin in Treating Patients With Hematologic Cancer

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed myelodysplastic syndrome (MDS) * Refractory anemia * Primary refractory leukopenia or thrombocytopenia with morphologic features of MDS * Refractory anemia with excess blasts (RAEB) * Refractory anemia with ringed sideroblasts * RAEB in transformation * Must have excess blasts or be hematopoietically compromised, defined as one of the following: * RBC transfusion dependent * Granulocyte count less than 1,000/mm\^3 * Platelet count less than 50,000/mm\^3 OR * Diagnosis of chronic myelomonocytic leukemia * Hematopoietically compromised (as defined above) OR * Excess blasts OR * Evaluable disease related symptomatology (organomegaly or leukemia cutis) OR * Diagnosis of acute myeloid leukemia * WBC less than 20,000/mm\^3 and stable for at least 2 weeks * Unlikely to require cytotoxic therapy during study * No CNS or pulmonary 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) * No disseminated intravascular coagulation Hepatic: * Bilirubin less than 2.0 mg/dL (unless due to hemolysis or Gilbert's syndrome) Renal: * Creatinine less than 2.0 mg/dL Other: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception for 2 weeks prior, during, and for 3 months after study * No active infection PRIOR CONCURRENT THERAPY: Biologic therapy: * See Disease Characteristics * At least 3 weeks since prior biologic therapy, including hematopoietic growth factors, and recovered Chemotherapy: * See Disease Characteristics * At least 3 weeks (1 month for MDS patients) since prior chemotherapy and recovered Endocrine therapy: * Not specified Radiotherapy: * At least 3 weeks since prior radiotherapy and recovered Surgery: * Not specified