PA038 Down syndrome patients with acute lymphoblastic leukemia have an intermediate prognosis with high infectious morbidity

Purpose: Even with modern therapy the outcome of ALL in children with Down’s syndrome (DS) remains inferior to non-DS patients. The higher incidence of infections in this group of patients may result not only in toxic-mortality, but may also impact on leukemia-related outcomes due to therapy omissions and delays.Method: This retrospective analysis looks at the outcome of DS patients with ALL diagnosed between 1997 and 2009 at our institution.Results: Of 24 patients, 14 were males with a median age of 4.8 years (mean5.0þ0.53 years; range 1.4–12.8 years) at diagnosis. Two patients had corrected congenital cardiac defects. The mean WBC count was 35.8 x 109/L (SEMþ24.66; range 0.89–500). All patients had precursor B-cell phenotype, two had CNS disease and none had any risk-associated cytogenetic features. Two patients received 3-druginduction and 21 were started on a 4-drug induction. There were three early deaths during induction; one patient died of parainfluenza-related ARDS, one with multi-organism sepsis and H1N1 influenza infection and the third with disseminated aspergillosis. Of 22 patients who were evaluated for BM response at day 14 only one had residual leukemia, with 50% blasts. All 21 patients who completed induction achieved CR. OS at a median follow-up of 3 years is 69% compared to 81% for non-DS pre-B ALL patients treated during the same time period with similar protocols. Five relapsed (2 BM, 2 CNS, 1 BM+CNS) at a median of 11.8 months; RFS is 73.2%at a median of 3.1 years. Infectious toxicity was high during induction and intensification phases of therapy compared to other phases.Conclusion: ALL patients with DS need to be treated with fairly intensive therapy in order to improve disease related outcomes; however, one has to balance this with the increased risk of infections, particularly during induction and intensification phases