Acute Leukemia in Children with Down Syndrome: A Report from the Hellenic HESPHO Group

Background/Objectives: Down syndrome (DS), affecting 1 in 1000 births, has been linked to an increased risk of acute leukemia (AL). Patients with DS–acute lymphoblastic leukemia (DS-ALL) have historically had inferior outcomes when they have received risk-adapted therapy. Transient abnormal myelopoiesis (TAM) constitutes a transient leukemia with spontaneous remission in the neonatal period or represents a preleukemic state, preceding DS–acute myeloid leukemia (DS-AML). DS-AML has a better prognosis than that of AML without DS (NDS-AML) due to genetic and biological underlying features, a better response to chemotherapeutic agents, and a lower frequency of relapses. Methods: This retrospective cohort study presents the DS-AL outcomes from a nationwide survey in pediatric oncology centers. A total of 20 patients were studied, 10 with DS-ALL, 4 with DS-AML, 5 with TAM, and 1 with DS-AML after TAM, at median follow-ups of 9.25 (0.6–17.42) years and 7.25 (0.25–18.25) years for DS-ALL and DS-AML, respectively. Results: The median age at diagnosis was 4.7 (1.16–13.83) and 1.92 (1.25–3) years for ALL and AML, respectively. All DS-ALL patients had B-cell precursor ALL and achieved complete remission (CR). One patient relapsed and succumbed due to a severe infection. Three DS-AML patients had AMKL. All DS-AML patients achieved CR. One patient with TAM demanded treatment, all achieved CR, and one progressed to DS-AML. The overall survival (OS) was 70% and 80% for DS-ALL and DS-AML. Conclusions: The improved survival rates of our patients have been due to new protocols with less toxic therapies and better supportive care.