Combination Chemotherapy in Treating Patients With Acute Myeloid Leukemia or Myelodysplastic Syndrome

OBJECTIVES: I. Determine the toxicity, remission rate, event-free survival, and overall survival following induction with cytarabine/mitoxantrone (ARA-C/DHAD), intensification with ARA-C and etoposide (VP-16), and consolidation with cladribine (2-CdA) and VP-16 in patients with acute myeloid leukemia (AML) that is secondary, in first relapse, or has failed initial remission induction therapy. II. Compare the remission induction rate and event-free survival on this trial with prior second-line studies (i.e., protocols CCG-243, CCG-201, and CCG-261P). III. Compare survival of patients on this trial with the survival of patients relapsing or failing to achieve an initial complete remission (CR) on previous front-line AML trials (i.e., protocols CCG-251, CCG-213, CCG-2861, and CCG-2891). IV. Determine the frequency and prognostic significance of mdr1 gene expression and p53, topoisomerase II, and deoxycytidine kinase gene mutations in these patients. V. Determine the disease-free and overall survival of patients achieving a CR on this study in relation to the post-intensification therapy received (i.e., bone marrow transplantation, chemotherapy, or no further therapy). VI. Determine the frequency and degree of abnormal cardiac function on echocardiogram or MUGA at 1 and 5 years in patients treated with mitoxantrone following anthracycline therapy during initial treatment. VII. Provide a control arm evaluating the safety of using phase I or II agents in an "upfront window" approach planned for future CCG studies. VIII. Determine the toxicity, remission rate, event-free survival, and overall survival in patients who fail to achieve a CR with ARA-C/DHAD induction and are then treated with 2-CdA/VP-16. IX. Determine the biologic characteristics, toxicity, remission rate, event-free survival, and overall survival following this treatment regimen in patients who develop AML as a second malignancy.

OUTLINE: Patients who do not achieve M1/M2a marrow following Induction proceed to Salvage Induction; all others proceed to Intensification. Patients receive Consolidation therapy on Regimen A, B, or C according to the investigator's choice. The following acronyms are used: ARA-C Cytarabine, NSC-63878 2-CdA Cladribine (2-Chlorodeoxyadenosine), NSC-105014 DHAD Mitoxantrone, NSC-301739 G-CSF Filgrastim, NSC-614629 HC Hydrocortisone, NSC-10483 HD High Dose MTX Methotrexate, NSC-740 PBSC Peripheral Blood Stem Cells TBI Total-Body Irradiation TIT Triple Intrathecal Therapy (IT ARA-C/IT HC/IT MTX) VP-16 Etoposide, NSC-141540 INDUCTION: 2-Drug Combination Chemotherapy plus CNS Prophylaxis/Therapy. ARA-C/DHAD; G-CSF; plus IT ARA-C and, if CNS disease at entry, TIT. SALVAGE INDUCTION: 2-Drug Combination Chemotherapy. 2-CdA/VP-16. INTENSIFICATION: 2-Drug Combination Chemotherapy followed, as indicated, by Radiotherapy. HD ARA-C/VP-16; followed, in patients with persistent CNS disease, CNS relapse, or chloromas, by irradiation using megavoltage equipment (minimum Co60 and maximum 6 MV x-rays or electrons). CONSOLIDATION: Regimen A: 2-Drug Combination Chemotherapy. 2-CdA/VP-16. Regimen B: Myeloablative Chemoradiotherapy followed by Hematopoietic Rescue. TBI (equipment unspecified) with electron boosts to the testes, chest, extramedullary sites, and, if indicated, craniospinal region; VP-16; followed by allogeneic or autologous bone marrow or PBSC. Regimen C: No further therapy.

PROJECTED ACCRUAL: A total of 90 patients will be entered. The study may be closed if there are 7 or more deaths in the first 45 patients who complete Intensification.

DISEASE CHARACTERISTICS: Acute myeloid leukemia (AML) or myelodysplastic syndrome in one of the following categories: In first relapse Failed to achieve initial complete remission Newly diagnosed secondary AML eligible Required bone marrow status: Greater than 25% blasts (M3) OR Persistent abnormal clone on cytogenetics and 5-25% blasts (M2) No Fanconi's anemia

PATIENT CHARACTERISTICS: Age: Under 22 Performance status: Not specified Hematopoietic: See Disease Characteristics Hepatic: Bilirubin no greater than 1.5 times normal AST or ALT less than 4.0 times normal Renal: Creatinine no greater than 1.5 times normal OR Creatinine clearance or GFR greater than 70 mL/min per 1.73 square meters or GFR in equivalent institutional normal range Cardiovascular: Shortening fraction greater than 27% by echocardiogram or in institutional normal range OR Ejection fraction greater than 47% by radionuclide angiogram

PRIOR CONCURRENT THERAPY: No more than 1 prior treatment No prior salvage therapy No prior mitoxantrone