The clinical spectrum of adult acute myeloid leukemia (AML) associated with core binding factor (CBF) translocations

Abstract

6513 Background: Although adults with AML containing CBF translocations [t(8;21) or inv(16)/t(16;16)] have a high complete response (CR) rate and improved overall survival (OS) compared to other AML patients (pts), not everyone does well. Methods: In order to better understand the spectrum of CBF-associated AML, we analyzed 373 pts with newly diagnosed CBF-related AML treated on SWOG, ECOG or MDA protocols. Results: Pts ranged in age from 16–83 (median 39) with a slight male predominance (56%). Overall, 53% of pts had inv(16) or t(16;16) while 47% had t(8;21); 58% had chromosomal abnormalities in addition to the CBF translocation. Pts with t(8;21) tended to be younger (p=0.03), have lower white counts (p<0.0001) and more often have additional chromosomal abnormalities (p<0.0001). CR was achieved in 86% of pts (95% confidence interval [CI] 82–89%) and the estimated resistant disease (RD) rate was 8% (CI 5–12%). Increasing age was the major factor associated with a decreased CR rate (p=0.0029) and increased incidence of RD (p=0.0014). OS at 10 years was 43% (CI 38–49%), and was significantly lower in older pts (p<0.0001) and those with higher peripheral blast percentage (p=0.0001). Relapse-free survival (RFS) was 40% (CI 34–46%) at 10 years and likewise was associated with age and peripheral blast percent. The treatment results did not differ significantly between pts with t(8:21) versus inv(16) and were not significantly influenced by the presence of additional chromosomal abnormalities. Conclusions: Although pts with CBF-associated AML do relatively well with 43% 10-year OS, considerable improvement is needed, particularly in older patients and those presenting with a higher percent of blasts in their peripheral blood. No significant financial relationships to disclose.