Genotype-outcome correlations in pediatric AML: the impact of a monosomal karyotype in trial AML-BFM 2004

We conducted a cytogenetic analysis of 642 children with de novo acute myeloid leukemia (AML) treated on the AML-Berlin-Frankfurt-Münster (BFM) 04 protocol to determine the prognostic value of specific chromosomal aberrations including monosomal (MK + ), complex (CK + ) and hypodiploid (HK + ) karyotypes, individually and in combination. Multivariate regression analysis identified in particular MK + ( n =22) as a new independent risk factor for poor event-free survival (EFS 23±9% vs 53±2% for all other patients, P =0.0003), even after exclusion of four patients with monosomy 7 (EFS 28±11%, P =0.0081). CK + patients without MK had a better prognosis ( n =47, EFS 47±8%, P =0.46) than those with MK + ( n =12, EFS 25±13%, P =0.024). HK + ( n =37, EFS 44±8% for total cohort, P =0.3) influenced outcome only when t(8;21) patients were excluded (remaining n =16, EFS 9±8%, P