Children with Down syndrome (DS) have an increased risk for acute lymphoblastic leukemia (ALL). Although previous studies have shown that DS-ALL differs clinically and genetically from non-DS-ALL, much remains to be elucidated as regards genetic and prognostic factors in DS-ALL.
To address clinical and genetic differences between DS-ALL and non-DS-ALL and to identify prognostic factors in DS-ALL, we ascertained and reviewed all 128 pediatric DS-ALL diagnosed in the Nordic countries between 1981 and 2010. Their clinical and genetic features were compared with those of the 4,647 B-cell precursor (BCP) ALL cases diagnosed during the same time period.
All 128 DS-ALL were BCP ALL, comprising 2.7% of all such cases. The 5-year event-free survival (EFS) and overall survival (OS) were significantly (P?=?0.026 and P?=?0.003, respectively) worse for DS-ALL patients with white blood cell counts =50 ? 109/l. The age distributions varied between the DS and non-DS cases, with age peaks at 2 and 3?years, respectively; none of the DS patients had infant ALL (P?=?0.029). The platelet counts were lower in the DS-ALL group (P?=?0.005). Abnormal karyotypes were more common in non-DS-ALL (P?