Pediatric acute promyelocytic leukemia: all-transretinoic acid therapy in a Brazilian pediatric hospital.

Acute promyelocytic leukemia (APL) is an uncommon form of pediatric acute nonlymphocytic leukemia. It is characterized by clinical (refractory coagulopathy), morphologic (promyelocytic differentiation arrest), and cytogenetic t(15;17) hallmarks. The introduction of all-transretinoic acid (ATRA) or tretinoin, a biologic response modifier, in its therapy was followed by dramatic improvement in its outcome. To show the results of APL treatment in our hospital, we reviewed the information about 15 patients less than 18 years old, newly diagnosed with APL between November 2002 and November 2006. The diagnosis was made upon examination of bone marrow aspirates. The clinical charts were searched for data regarding clinical presentation, diagnosis, initial response with induction therapy, toxicity of ATRA, and antracyclic drug (daunorubicin). The median age was 10 years; the male-to-female ratio was 2:1. Fourteen patients received induction chemotherapy. Thirteen achieved complete remission. Six patients showed signs of coagulopathy. Only 1 patient was diagnosed with ATRA syndrome. There was a death owing to sepsis before the beginning of the therapy and 2 relapses with death associated with the therapy discontinuation. Preliminary results are encouraging and confirm that ATRA is safe and efficacious as first choice therapy for APL.