Combination Chemotherapy and Bone Marrow Transplantation in Treating Patients With Leukemia or Myelodysplastic Syndrome

DISEASE CHARACTERISTICS: Primary or secondary acute nonlymphocytic leukemia and acute lymphocytic leukemia in one of the following states: First or greater remission Early relapse Chronic myelogenous leukemia (CML) in one of the following states: First or greater chronic phase Treatment on this protocol is preferred to total body irradiation containing protocols for patients under 40 with CML in stable first chronic phase who are otherwise eligible for allogeneic bone marrow transplantation Accelerated phase Myeloid or lymphoid blast crisis Myelodysplastic syndromes of the following types: Refractory anemia Refractory anemia with ringed sideroblasts Refractory anemia with excess blasts Chronic myelomonocytic leukemia Multiple myeloma Non-Hodgkin's lymphoma HLA identical bone marrow donor available Unable to undergo total body irradiation because of one of the following reasons: Under age 2 (CNS still growing and at high risk of permanent radiation injury) Prior high dose radiotherapy to the brain, lungs, heart, liver, or abdomen In relapse following allogeneic or autologous transplant using total body irradiation for ablation, but eligible for a second transplant No current CNS involvement PATIENT CHARACTERISTICS: Age: 50 and under (patients aged 51-55 accrued on a case-by-case basis after discussion and approval by the BMT service) Performance status: Karnofsky 70-100% Life expectancy: Greater than 8 weeks Hematopoietic: Not specified Hepatic: Bilirubin less than 1.5 mg/dL AST no greater than 3 times normal Neither value increasing for at least 2-4 weeks prior to transplant Renal: Creatinine less than 2 times normal and not rising for at least 2-4 weeks prior to transplant OR Creatinine clearance greater than 80 mL/min Cardiovascular: Left ventricular ejection fraction at least 50% Cardiac function good Pulmonary: No severe restrictive lung disease No chronic obstructive pulmonary disease Other: No active viral or bacterial infection at transplant No coexisting medical problem that would significantly increase the risk of the transplant procedure Not pregnant PRIOR CONCURRENT THERAPY: Prior therapy allowed, including prior bone marrow transplant