Azacitidine and low-dose cytarabine in palliative patients with acute myeloid leukemia and high bone marrow blast counts - a retrospective single-center experience

We retrospectively analyzed and compared the efficacy and toxicity of azacitidine (AZA) and low-dose cytarabine (LD-Ara-C) in 65 palliative patients with acute myeloid leukemia (AML) showing high bone marrow blast counts (>= 30%) before start of treatment. Twenty-seven and 38 patients received AZA and LD-Ara-C, respectively. The median patient age was 71 yr. Patient and disease characteristics did not differ between the treatment groups, except for BM blast counts, and peripheral leukocyte and blast counts which were significantly higher in the LD-Ara-C group. AZA and LD-Ara-C were first-line treatment in 12 (44%) and 17 patients (45%), respectively. Response and hematologic improvement rates were low and similar in both treatment groups. In both treatment groups, most common non-hematologic toxicities included febrile neutropenia, pneumonia, and bleedings without significant differences regarding frequencies. Estimated 1-yr survival rates were 15% (95% CI 8-22) and 13% (95% CI 7-19) in the AZA and LD-Ara-C groups, respectively, without statistically significant difference. In multivariate analysis (n = 65), previous treatment (HR 2.27, 95% CI 1.00-5.22, P = 0.05) and adverse cytogenetics (HR 2.50, 95% CI 1.20-5.22, P = 0.02) were independent predictors of poor survival. In our center and within the limitations of a retrospective study, both treatment regimens showed similar but limited efficacy in palliative patients with AML and high BM blast counts.