Clinical Useful Prognostic Index for Adult Patients with Acute Myeloid Leukemia in First Relapse.

The treatment of acute myeloid leukemia (AML) in first relapse is associated with unsatisfactory rates of complete responses that are usually short lived. Previously proposed prognostic classification methods serving therapeutic decisions and evaluation of investigational treatment strategies at relapse of AML have been based on the duration of the relapse free interval and have largely neglected the influence of other known prognostic factors. Here we present an improved clinically useful prognostic index. This index has been developed from a multivariate analysis of 667 AML patients in first relapse among 1540 newly diagnosed non-M3 AML patients of age 15 to 60 years entered into three successive HOVON/SAKK Collaborative Group trials. The score, which has a range of 0 to 14 points, uses four relevant parameters. The parameters are: length of relapse free interval after first complete remission (more than 18 months: 0 points; 7 to 18 months: 3 points; 6 months or less: 5 points), cytogenetics at diagnosis (t(16;16) or inv(16): 0 points; t(8;21): 3 points; other cytogenetics: 5 points), age at relapse (35 years or younger: 0 points; 36 to 45 years: 1 point; older than 45 years: 2 points) and whether or not a previous stem cell transplantation (SCT) has been undertaken in first complete remission (no SCT: 0 points; previous SCT: 2 points). These points were assigned following estimations of the relative values of each of these factors contributing to outcome. Ultimately, three risk groups were defined: a favorable prognostic group A (0 to 6 points; overall survival of 70% at one year and 46% at five years), an intermediate risk group B (7 to 9 points; overall survival of 49% at one year and 18% at five years), and an unfavorable risk group C (10 to 14 points; overall survival of 16% at one year and 4% at five years). Thus, four commonly applied clinical parameters may identify among patients with AML in first relapse those for salvage or investigational therapy.