Feasibility and results of autologous stem cell transplantation in de novo acute myeloid leukemia in patients over 60 years old. Results of the CETLAM AML-99 protocol.

BACKGROUND AND OBJECTIVES The benefits of high-dose cytarabine, anthracyclines and hematopoietic stem cell transplantation in the treatment of acute myeloid leukemia (AML) are greater in younger rather than in older patients. We assessed the proportion of patients over 60 years with de novo AML who qualified for intensive therapy and determined the feasibility and results of autologous stem cell transplantation (ASCT) in first complete remission (CR). DESIGN AND METHODS Induction therapy included idarubicin, cytarabine and etoposide. Patients who achieved CR received one cycle of mitoxantrone and cytarabine and ASCT as consolidation therapies. RESULTS Over a 4-year period, 258 patients were registered of whom 135 (52%) were enrolled for intensive treatment. The CR rate was 61%, advanced age (p=0.033) and unfavorable cytogenetics (p=0.015) emerged as independent negative prognostic factors for CR. The 2-year overall survival (OS) was 23 % (CI 14%-30%) and was poorer in patients with unfavorable cytogenetics (p=0.035), age over 70 years (p=0.019) or leukocytosis (p=0.006). Only 27% of the potential candidates underwent ASCT. The probability of 2-year leukemia-free survival after consolidation was 39% (CI 6%-71%) for these patients and 22% (CI 6% - 39%) for candidate patients not undergoing ASCT (p=0.07). INTERPRETATION AND CONCLUSIONS Over 25% of the patients 60 to 70 years with de novo AML benefit from standard intensive treatment. In these patients, ASCT has a tolerable toxicity and may have a positive impact on leukemia-free survival.