Resumen
An association of deletions in the IKZF1 gene (IKZF1del) with poor prognosis in acute lymphoblastic leukemia (ALL) has been demonstrated. However, the co-occurrence of IKZF1del with deletions in other genes (IKZF1plus) seems to better define prognosis. Our aim was to analyze the influence of IKZF1del and/or IKZF1plus profiles on the survival of children with ALL. We analyzed 1023 eligible cases who were classified into three subsets: IKZF1not-del: IKZF1-not-deleted (n = 835), IKZF1del: IKZF1deleted (n = 94) and IKZF1plus: IKZF1del plus deletion of other genes (n = 94). Leukemia-free-survival probability (standard deviation) (LFSp(SE)) was 75 (2)% for IKZF1not-del, 51 (6)% for IKZF1del and 48 (6)% for IKZF1plus (p-value < 0.00001). The LFSp(SE) according to ALL-IC risk-group stratification showed a statistically significant difference within Intermediate-Risk patients, LFSp (SE) being 77 (2)% for IKZF1not-del, 61 (10)% for IKZF1del and 54 (7)% for IKZF1plus (p-value = 0.0005). The LFSp(SE) of the high-risk group was: 61 (4)% IKZF1not-del, 38 (8)% IKZF1del and 35 (9)% IKZF1plus (p-value = 0.0102). Thus, the IKZF1 status was shown to define a population of patients with a poor outcome, mainly in those with intermediate risk. However, not-significant differences were observed between the LFSp of IKZF1del versus IKZF1plus groups. The study of the IKZF1 status should be incorporated into the risk-group stratification of pediatric ALL.