Neoplastic disorders of hematopoiesis in children with Down's syndrome - A single institution experience in Taiwan

Background and Purpose: Children suffering from Down's syndrome (DS) are predisposed to the development of neoplastic disorders of the hematopoietic system and tend to display many unique characteristics. This study analyzed the clinical characteristics and treatment outcomes of 16 children with DS who developed neoplastic disorders. Methods: All DS patients aged < 18 years of age with a diagnosis of leukemia or myelodysplastic syndrome (MDS) from 1990 to 2002 were included in this retrospective study. The clinical and laboratory characteristics of patients, including age at diagnosis, gender, initial hemogram, cytogenctic findings, immimophenotype, treatment regimen and outcomes were analyzed. Results: Sixteen patients met the inclusion criteria. Among them, 9 patients (56%) had acute myeloid leukemia (AML), mainly of the megakaryoblastic subtype. All 8 AML patients who had analyzable metaphase cells revealed clonal chromosomal abnormalities in addition to trisomy 21. Three of these patients developed MDS prior to the onset of AML. Of the 5 patients who underwent chemotherapy, 3 remained in remission with a survival time of 29, 59, and 109 months, and the remaining 2 died as a consequence of chemotherapy toxicity. Among the 6 patients (38%) who developed transient myeloproliferative disorder, 2 were lost to follow-up, 2 died from DS-associated congenital heart abnormalities and 2 survived without any AML changes. The remaining 1 patient (6%) who developed ALL was still in his first remission although this patient suffered profound chemotherapy complications during treatment. Conclusions: This study found that AML is the most common hematologic neoplasm in Taiwanese children with DS, especially megakaryoblastic leukemia. This finding is comparable to the reported results from related studies in different countries. Long-term remission of AML in DS patients can be achieved with appropriate treatment.