Copy Number Alterations in patients with mature B (Burkitt-type) acute lymphoblastic leukaemia treated with specific immunochemotherapy

Abstract

S174 EBF1 and PAX5 deletions. In the IKZF1 deleted cohort, 13 patients (28%) showed whole gene deletions and Ik6 was the most recurrent short isoform (26%). Multivariate analysis showed that advanced age andEBF1 deletions were negative prognostic factors for achieving Complete Remission (CR) andWBC count and IKZF1 deletions significantly reduced CR duration in both the total series and in the Ph negative subgroup. Interestingly, there were significant differences in relapse rates between whole and partial IKZF1 deletions. IKZF1 haploinsufficient patients had a probability of CR duration at 6 years of 70% 36% vs. 14% 17% of partial gene deletion carriers (p1⁄40.013). Advanced age and CDKN2A/B deletions were predictors for overall survival in the whole series but also in the Ph negative subgroup. Conclusions: IKZF1, EBF1 and CDKN2A/B genetic abnormalities could help to better define prognostic subgroups in adult patients with B-ALL. Deletion Duplication IKZF1 46 (34%) 1 (1%) EBF1 15 (11%) 10 (7%)