Acute promyelocytic leukemia in childhood and adolescence: treatment results of a modified AIDA protocol at a Brazilian center

INTRODUCTION: Acute promyelocytic leukemia currently presents an excellent chance of cure with protocols based on all-trans-retinoic acid (ATRA) and anthracycline or only differentiation agents. However, high early mortality rates continue to be reported METHODS: Between 2000 and 2018, patients were enrolled and retrospectively analyzed by medical records. A modified AIDA protocol, with a 1-year shortening of the treatment duration, reduction in the number of drugs and a strategy to reduce early mortality by the postponement of the initiation of anthracyclines were employed. Overall and event-free survival rates and toxicity were analyzed RESULTS: Thirty-two patients were enrolled, of whom 56% were female, with a median age of 12 years and 34% belonged to the high-risk group. Two patients had the hypogranular variant and three had another cytogenetic alteration, in addition to the t(15;17). The median start of the first anthracycline dose was 7 days. There were two early deaths (6%) due to central nervous system (CNS) bleeding. All patients achieved molecular remission after the consolidation phase. Two children relapsed and were rescued by arsenic trioxide and hematopoietic stem cell transplantation. The presence of disseminated intravascular coagulation (DIC) at diagnosis (p = 0.03) was the only factor with survival impact. The five-year event-free survival (EFS) was 84% and 5-year overall survival (OS) was 90% CONCLUSION: The survival results were comparable to those found in the AIDA protocol, with a low rate of early mortality in relation to the Brazilian reality.