All-trans-retinoic acid (ATRA): pediatric acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloblastic leukemia (AML). In this report, we present the clinical features, management, and outcome of pediatric patients with APL treated with all-trans-retinoic acid (ATRA). Of 52 newly diagnosed cases of APL between February 1992 and December 1996, 15 were in the pediatric age group (younger than 15 years). Four patients were treated with ATRA alone and 11 were allocated to receive ATRA followed by chemotherapy. Eighty-six percent of the patients achieved a complete response. The patients who received ATRA alone as maintenance therapy had relapses with a median duration of remission of 8 months (range 6-12). The patients who received ATRA, followed by consolidation chemotherapy, had a prolonged duration of remission, with a median of 20 months (range 13-28). In addition, rapid correction of coagulopathy was observed in these patients. The median duration for correction of coagulopathy was 7 days (range 5-11) and the median duration for recovery from neutropenia after chemotherapy was 10 days (range 7-20). Two major side effects of ATRA were hyperleukocytosis and retinoic acid syndrome. Significantly prolonged disease-free survival was seen in patients who received ATRA with chemotherapy. APL is not uncommon in the pediatric age group. ATRA was well-tolerated by these patients. Consolidation with chemotherapy helps in prolonging the disease-free survival in patients with APL in comparison to treatment with ATRA alone.