TEL/AML1+ ACUTE LYMPHOBLASTIC LEUKEMIA IN THE GREEK PEDIATRIC POPULATION

INTRODUCTION: TEL / AML1 + acute lymphoblastic leukemia (ALL) is considered to be a distinct nosological entity with excellent prognosis, but recent studies have indicated significant clinical heterogeneity. OBJECTIVE: In this study, we attempted to estimate the incidence and clinical features of TEL / AML1 + ALL for the first time in a representative cohort of Greek pediatric patients. METHODS: One hundred twenty children ( TEL / AML1 with interphase fluorescence in situ hybridization by using a commercial probe set. All patients were treated as either standard risk (SR) or high-risk (HR) cases according to a modified BFM-95 (Berlin-Frenkfurt-Munster) protocol. Follow-up ranged between 5 and 87 months (median: 45 months). RESULTS: Twenty-six patient (all of them will ALL of B-cell origin [24.3%]) were found to be positive for TEL / AML1 . The presence of TEL / AML1 was significantly associated with younger age and lower white blood cell count at diagnosis but not with remission duration or overall survival rate. The number of children who relapsed (1 vs 7) or succumbed (1 vs 5) was comparable between the TEL / AML1 + and TEL / AML1 − groups of children with ALL of B-cell origin. CONCLUSIONS: The incidence of TEL / AML1 in Greece seems comparable to that in other European and Mediterranean countries. As in most European studies, the independent prognostic value of TEL / AML1 is in doubt, because it is closely associated with other favorable factors. In this series, the modification of the therapeutic regimen (ie, omission of the SR arm) may be responsible for the similar outcome in TEL / AML1 + and TEL / AML1 − cases, because it seems to lower the relapse risk for all children with ALL.