Infant leukaemia is a rare disease but the 3rd most frequent malignancy in this age group. Both acute lymphoblastic leukaemia and acute myeloid leukaemia in the first year of life have particular clinical and biological characteristics such as B-cell phenotype with co-expression of myeloid markers in acute lymphoblastic leukaemia, FAB M5 or M7 in acute myeloid leukaemia, the presence of extramedullary symptoms and a high frequency of KMT2A rearrangements. Survival rates for infant acute leukaemia are worse than for older children. In this study, the characteristics and outcome of 50 infants with acute lymphoblastic leukaemia and acute myeloid leukaemia treated at the University Hospitals of Ghent and Leuven between 1989 and 2015 were studied and correlated with literature data. With event-free survival and overall survival rates of 44% and 52% for the entire cohort, the outcome of these patients was comparable to those in published clinical trials. In general, the event-free survival and overall survival was superior in acute myeloid leukaemia compared to acute lymphoblastic leukaemia infants and not influenced by age (< or ≥6 months), white blood cell count at diagnosis or presence of a KMT2A rearrangement. For future trials in infant leukaemia, the high number of early deaths, toxic deaths and relapses remain the most challenging problems.

(BELG J HEMATOL 2018;9(2):57–63.)