[Incidence and prognostic significance of Auer rods in children with acute myeloid leukemia in the studies AML-BFM-78 and -83]

Abstract

The prognostic significance of Auer rods in children with AML was investigated in 129 patients of the study AML-BFM-78 and 154 patients of the study AML-BFM-83. Auer rods were found in 68 patients (53%) in the study AML-BFM-78 and 69 patients (45%) in the study AML-BFM-83. The incidence was higher in the subtypes FAB M1 (61%) and M2 (75%) compared to the subtypes FAB M4 (44%) and M5 (5%). In both studies the remission rate was higher in Auer rod-positive patients. Moreover, in the study AML-BFM-83 patients with Auer rods had a significant longer remission duration: the probability of an event-free interval (EFI) of 5 years was 77% (SD 6%) in Auer rod-positive patients compared with 44% (SD 7%) in Auer rod-negative patients (p less than 0.01). In the study AML-BFM-78 no differences regarding remission duration between both groups were detected. Analysis of the individual FAB subtypes revealed a significant higher event-free survival rate (EFS) after 5 years in Auer rod-positive compared with 18% (SD 12%) in Auer rod-negative patients (p less than 0.0001). No prognostic significance of Auer rods in other subtypes could be detected. In the overall group of all patients absence of Auer rods was associated with the unfavourable parameters hyperleucocytosis (greater than or equal to 100 x 10(3)/microliters) and acute monocytic leukemia (FAB M5) (p less than 0.01, p less than 0.001, respectively). The multivariate analysis in the study AML-BFM-83 showed that Auer rods were of prognostic significance independent from the initial leukocyte count and the FAB type M5.(ABSTRACT TRUNCATED AT 250 WORDS)