Relapsed acute megakaryoblastic leukemia in Down syndrome (AMKL-DS) may be cured with chemotherapy alone, without stem cell transplantation (HSCT)

Abstract

17543 Background: Children with recurrent AMKL -DS have an extremely poor prognosis without HSCT. Methods: We report a case of a relapsed AMKL-DS cured with intensive chemotherapy alone, without HSCT. Results: A 19 month old boy with Down syndrome, who had transient leukemia as a newborn, developed AMKL-DS (GATA1 positive) and was treated with four cycles of CI-TAD: continuous infusion of cytarabine and daunorubicin, and oral thioguanine for four days, and intrathecal cytarabine; followed by two cycles of high dose cytarabine plus L-Asparaginase; and three weekly doses of intrathecal cytarabine. Although he achieved remission at the completion of first cycle of the induction chemotherapy, he relapsed within 6 weeks after the completion of therapy. He then received the following chemotherapy over the next six months: Cycle 1 and 2. High dose Ara-C ( 33. 3 mg/kg q 12 hours x 8 doses) on days 0 to 3 plus mitoxantrone 0. 4 mg/kg/day x 4 on days 3 to 6 Cycle 3. High dose Ara-C 33. 3 mg/kg q 12 hours x 8 doses Cycle 4 and 5 (FLAG): Fludarabine 0. 8 mg/kg/day x 4 plus Ara-C 67 mg/kg/d x 4 and G-CSF 10 mcg/kg/day x 4 all on days 0 to 3. He achieved complete remission after the 1st cycle of chemotherapy, and underwent further cycles of chemotherapy while waiting for HSCT from an unrelated donor. But after the 5th cycle of chemotherapy, he developed a pulmonary lesion of fungal etiology for which he received three months of therapy with liposomal amphotericin. Because of a persistent lung lesion on imaging, he was considered ineligible for HSCT, and no further therapy was given. His bone marrow aspirate after the 3rd cycle of therapy was negative for GATA1. He has been disease-free for 59 months after the completion of his last cycle of chemotherapy, and he is currently in good health without any evidence of pulmonary or cardiac dysfunction. Conclusions: Intensive chemotherapy alone, without HSCT, may be curative for relapsed AMKL- DS. No significant financial relationships to disclose.