Definition of a standard-risk group in children with AML

To define paediatric AML patients with a favourable outcome in order to des ign a risk-adapted therapy we analysed 489 children under 17 years of age t reated similarly in studies AMT,BFM 83 and 87. 369 patients (75.4%) achieve d remission. Estimated probabilities of survival, event-free survival (EFS) and disease-free survival (DFS) at 5 years were 50% (SE 2%), 43% (SE 2%) a nd 58% (SE 3%), respectively Multivariate analysis revealed bone marrow bla sts on day 15, morphologically defined risk groups and hyperleucocytosis to be of prognostic value. EFS at 5 years estimated for patients with less th an or equal to 5% and >5% blasts on day 15 were 56% (SE 3%) v 27% (SE 4%); for the favourable morphological subgroups (M1/M2 with Auer rods, M3 and (M 4eo) it was 60%; (SE 4%) compared with other patients (33%, SE 3%), P (Kapl an-Meier) = 0.0001 each. Hyperleucocytosis proved tu be an independent prog nostic factor, indicating a high risk, especially for early failure. The sp ecific Karyotypes t(8;21), t(15;17) and inv16 were closely related to the f avourable morphology and outcome was in the same range. We conclude that fo r the definition of a standard-risk group a combination of morphological an d response criteria may be sufficient. The standard-risk group defined by f avourable morphology and a blast cell reduction on day 15 (not required for M3) comprises 31% of all patients, P survival, pEFS and pDFS at 5 years we re 73% (SE 4%), 68% (SE 5%) and 76% (SE 4%), respectively.