Down syndrome and acute leukemia in children: a 10-year retrospective survey from Childrens Cancer Study Group.

Review of 5406 children with acute lymphoblastic (ALL) or nonlymphoblastic leukemia (ANLL) registered with Childrens Cancer Study Group (CCSG) since 1972 identified 115 patients (2.1%) with Down syndrome. The proportion of patients with Down syndrome was the same for ALL (2.1%) and ANLL (2.1%). Patients with ALL with and without Down syndrome did not differ significantly with respect to age at diagnosis, sex, race, morphology (FAB classification), cell surface markers, initial white blood cell count, pretreatment hemoglobin value, hepatomegaly, lymphadenopathy, presence of mediastinal mass, CNS disease at diagnosis, or prognostic group as defined by age and initial white blood cell count. Patients with ALL-Down syndrome less frequently had splenomegaly, had lower pretreatment platelet counts, and more often had normal or elevated IgG or IgA levels. In addition, they had a significantly lower rate of remission (81% versus 94%), a higher mortality during induction therapy (14% versus 3%), and a poorer overall survival with 5-year life table rates of 50% versus 65% (P less than 0.001). If an initial remission was achieved, there were no significant differences with respect to remission duration, survival, or disease-free survival. Patients with ANLL-Down syndrome were younger at diagnosis than those without Down syndrome. There was no significant difference in the remission rates between these patients. Analysis of findings in patients with ANLL provided results similar to those obtained for patients with ALL with regard to clinical outcome after achievement of an initial remission.