Acute Promyelocytic Leukemia in Children: a Report on Eleven Cases

We report 11 children (aged less than 20 years) with acute promyelocytic leukemia (APL), who represented 14% of our total number of patients with APL. There were 8 girls and 3 boys and the median age was 13.5 (range 3-19). Extramedullary leukemia was present in only 1 patient and hyperleukocytosis in 3 patients. Cytologically, 9 patients had "classical" APL, and 2 had the microgranular variant APL. Translocation (15;17) was present in all 4 karyotyped patients. Disseminated intravascular coagulation was seen in 8 patients at diagnosis, and was triggered by chemotherapy in 2 other cases. Induction chemotherapy was daunorubicin (DNR) alone in 6 patients, DNR + Ara C in 4 and zorubicin + Ara C in the remaining case. All patients received heparin during induction. Seven patients (64%) achieved complete remission (CR), 2 had resistant leukemia and 2 died during induction. Among the complete remitters, one received no further therapy and relapsed after 4 months, and another died of an unrelated cause after 4 weeks, while still in CR. The 5 others all relapsed after 3 to 13 months. Median survival was 5.5 months. Disease free survival (DFS) was significantly shorter than in our adult APL patients treated with the same regimens. APL is a rare disease in children and our results suggest that it may be associated with short remissions, especially when compared with adult APL. This could justify therapeutic reinforcement in these cases, such as allogeneic bone marrow transplantation, whenever possible, after CR has been achieved.