Acute leukaemia in infants less than 18 months of age: a retrospective analysis of 13 cases

Abstract

Clinical features, blast cell immunophenotype, cytogenetic findings and treatment outcome were analyzed in a retrospective study of 13 cases of infant leukaemia diagnosed in Queen Mary Hospital, Hong Kong, over a ten-year period. There were 11 cases of acute lymphoblastic leukaemia (ALL) and two cases of acute myeloid leukaemia (AML). Bulky disease with organomegaly, central nervous system (CNS) involvement and high white cell count were prominent features at presentation. Four out of 11 cases (37%) of ALL were common ALL antigen (CALLA) negative assuming an early B-precursor phenotype. Translocation 4;11 was found in one case out of seven analyzed (14%), giving a lower incidence when compared with published data, though the sample size was small. Among ALL cases, we found a complete remission (CR) rate of 91%. Most of them relapsed, giving a probability of event-free survival (EFS) of 20.8% at 48 months. Nevertheless, a significant number was salvaged and the total survival was 56.8% at 84 months. The findings showed that infant leukaemia had distinctive clinical and biological characteristics. A high risk for relapse was noted but the probability of survival in our series was encouraging.