Disease biology rather than age is the most important determinant of survival of patients > or = 60 years with acute myeloid leukemia treated with uniform intensive therapy

BACKGROUND: The objectives of the current study were to evaluate the outcome of patients > or = 60 years with acute myeloid leukemia (AML) treated uniformly with high-dose daunorubicin containing induction and modified high-dose cytosine arabinoside containing postremission therapy, and to identify factors predictive of complete disease remission (CR) and survival. METHODS: Between 1998 and 2002, the authors treated 117 newly diagnosed patients (acute promyelocytic leukemia excluded) with AML > or = 60 years (median, 67 years; range, 60-82 years). Karyotype (Medical Research Council classification) at diagnosis was categorized as good risk (n = 3), intermediate risk (n = 69), adverse risk (n = 26), and suboptimal/not done (n = 19). A normal karyotype was seen in 41 patients and 40 (34%) had secondary AML. RESULTS: The outcome of induction included the following: CR, 62 (53%); early death, 5 (4%); death during hypoplasia, 14 (12%); and resistant disease, 36 (31%). The 3-year event-free (EFS) and overall survival (OS) rates were 9% (95% confidence interval [95% CI], 3-16%) and 17% (95% CI, 9-29%), respectively. In a univariate analysis, cytogenetics, lactate dehydrogenase level, leukocyte count, and performance status were the significant factors for EFS and OS. Age was not a significant prognostic factor for either CR or survival. In a multivariate model, adverse-risk cytogenetics, previous history of myelodysplastic syndrome or antecedent hematologic disorder, and high leukocyte count (> 30 x 10(9)/L) were independent adverse prognostic factors for survival. The impact of adverse karyotype on EFS and OS was time dependent and was observed after 50 and 150 days, respectively. CONCLUSIONS: The authors concluded that candidacy for intensive therapy in older patients should be based on biologic features of disease and fitness, rather than on age.