Children with Down Syndrome
Children with Down syndrome have a tenfold to twentyfold increased risk of leukemia compared with children without Down syndrome; the ratio of acute lymphoblastic leukemia to acute myeloid leukemia (AML) is nevertheless typical for childhood acute leukemia. The exception is during the first 3 years of life, when AML, particularly the megakaryoblastic subtype, predominates and exhibits a distinctive biology characterized by GATA1 mutations and increased sensitivity to cytarabine.[1-9] Importantly, these risks appear to be similar whether a child has phenotypic characteristics of Down syndrome or whether a child has only genetic bone marrow mosaicism.
In addition to increased risk of AML during the first 3 years of life, about 10% of neonates with Down syndrome also develop a transient myeloproliferative disorder (TMD) (also termed transient leukemia). This disorder mimics congenital AML, but typically improves spontaneously within the first 3 months of life, though TMD can remit as late as 20 months. Although TMD is usually a self-resolving condition, it can be associated with significant morbidity and may be fatal in 10% to 20% of affected infants.[11-13] Infants with progressive organomegaly, visceral effusions, preterm delivery (less than 37-weeks gestation), bleeding diatheses, failure of spontaneous remission, laboratory evidence of progressive liver dysfunction (elevated direct bilirubin), and very high white blood cell count are at particularly high risk for early mortality.[12,14] Death has been reported to occur in 21% of these patients with high-risk TMD. Three risk groups have been identified based on the diagnostic clinical findings of hepatomegaly with or without life-threatening symptoms: (1) low risk includes those with neither finding (38% of patients and 92% ± 8% OS); (2) intermediate risk with hepatomegaly alone (40% of patients and 77% ± 12% overall survival [OS]); and (3) high risk with both characteristics (21% of patients and 51% ± 19% OS). Therapeutic intervention is warranted in patients in whom severe hydrops or organ failure is apparent. Several treatment approaches have been used, including exchange transfusion, leukapheresis, and low-dose cytarabine.
The mean time for the development of AML in the 10% to 30% of children who have a spontaneous remission of TMD but then develop AML has been reported to be approximately 16 months, with a range of 1 to 30 months.[11,15,17] Thus, most infants with Down syndrome and TMD who later develop AML will do so within the first 3 years of life. Patients with Down syndrome who develop AML with an antecedent TMD have superior event-free survival (EFS) (91% ± 5%) compared with such children without TMD (70% ± 4%) at 5 years, although this was not observed in another study. While TMD is generally not characterized by cytogenetic abnormalities other than trisomy 21, the presence of additional cytogenetic findings may connote an increased risk for developing subsequent AML.
Outcome is generally favorable for children with Down syndrome who develop AML.[18,19] The prognosis is particularly good (EFS exceeding 80%) in children aged 4 years or younger at diagnosis, the age group that accounts for the vast majority of Down syndrome patients with AML.[18,20] A large study of 451 children with AML and Down syndrome (age >6 months and <5 years) confirmed the generally favorable outcome for this patient population (7-year EFS of 78% and 7-year OS of 79%). Multivariate analyses revealed that white blood cell (WBC) count (≥20 × 109/L) and age (>3 years) were independent predictors for lower EFS, although 7-year EFS for the older population (>3 years) and for the higher WBC count population still exceeded 60%. Absence of leukemia cell cytogenetic abnormalities (other than trisomy 21), observed in approximately 30% of patients, independently predicted for inferior OS and EFS (7-year EFS of 65% compared with 82% for patients with aberrant karyotypes).
Appropriate therapy for younger children (aged ≤4 years) with Down syndrome and AML is less intensive than current standard childhood AML therapy, and hematopoietic stem cell transplant is not indicated in first remission.[3,17,18,20,22-25]
Children with mosaicism for trisomy 21 are recommended to be treated similarly to those children with clinically evident Down syndrome. Children with Down syndrome who are older than 4 years have a significantly worse prognosis. Although an optimal treatment for these children has not been defined, they are usually treated on AML regimens designed for children without Down syndrome.
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- Gamis AS: Acute myeloid leukemia and Down syndrome evolution of modern therapy--state of the art review. Pediatr Blood Cancer 44 (1): 13-20, 2005. [PUBMED Abstract]
- Bassal M, La MK, Whitlock JA, et al.: Lymphoblast biology and outcome among children with Down syndrome and ALL treated on CCG-1952. Pediatr Blood Cancer 44 (1): 21-8, 2005. [PUBMED Abstract]
- Massey GV: Transient leukemia in newborns with Down syndrome. Pediatr Blood Cancer 44 (1): 29-32, 2005. [PUBMED Abstract]
- Taub JW, Ge Y: Down syndrome, drug metabolism and chromosome 21. Pediatr Blood Cancer 44 (1): 33-9, 2005. [PUBMED Abstract]
- Crispino JD: GATA1 mutations in Down syndrome: implications for biology and diagnosis of children with transient myeloproliferative disorder and acute megakaryoblastic leukemia. Pediatr Blood Cancer 44 (1): 40-4, 2005. [PUBMED Abstract]
- Jubinsky PT: Megakaryopoiesis and thrombocytosis. Pediatr Blood Cancer 44 (1): 45-6, 2005. [PUBMED Abstract]
- Ge Y, Stout ML, Tatman DA, et al.: GATA1, cytidine deaminase, and the high cure rate of Down syndrome children with acute megakaryocytic leukemia. J Natl Cancer Inst 97 (3): 226-31, 2005. [PUBMED Abstract]
- Kudo K, Hama A, Kojima S, et al.: Mosaic Down syndrome-associated acute myeloid leukemia does not require high-dose cytarabine treatment for induction and consolidation therapy. Int J Hematol 91 (4): 630-5, 2010. [PUBMED Abstract]
- Homans AC, Verissimo AM, Vlacha V: Transient abnormal myelopoiesis of infancy associated with trisomy 21. Am J Pediatr Hematol Oncol 15 (4): 392-9, 1993. [PUBMED Abstract]
- Massey GV, Zipursky A, Chang MN, et al.: A prospective study of the natural history of transient leukemia (TL) in neonates with Down syndrome (DS): Children's Oncology Group (COG) study POG-9481. Blood 107 (12): 4606-13, 2006. [PUBMED Abstract]
- Muramatsu H, Kato K, Watanabe N, et al.: Risk factors for early death in neonates with Down syndrome and transient leukaemia. Br J Haematol 142 (4): 610-5, 2008. [PUBMED Abstract]
- Klusmann JH, Creutzig U, Zimmermann M, et al.: Treatment and prognostic impact of transient leukemia in neonates with Down syndrome. Blood 111 (6): 2991-8, 2008. [PUBMED Abstract]
- Gamis AS, Alonzo TA, Gerbing RB, et al.: Natural history of transient myeloproliferative disorder clinically diagnosed in Down syndrome neonates: a report from the Children's Oncology Group Study A2971. Blood 118 (26): 6752-9; quiz 6996, 2011. [PUBMED Abstract]
- Al-Kasim F, Doyle JJ, Massey GV, et al.: Incidence and treatment of potentially lethal diseases in transient leukemia of Down syndrome: Pediatric Oncology Group Study. J Pediatr Hematol Oncol 24 (1): 9-13, 2002. [PUBMED Abstract]
- Ravindranath Y, Abella E, Krischer JP, et al.: Acute myeloid leukemia (AML) in Down's syndrome is highly responsive to chemotherapy: experience on Pediatric Oncology Group AML Study 8498. Blood 80 (9): 2210-4, 1992. [PUBMED Abstract]
- Sorrell AD, Alonzo TA, Hilden JM, et al.: Favorable survival maintained in children who have myeloid leukemia associated with Down syndrome using reduced-dose chemotherapy on Children's Oncology Group trial A2971: a report from the Children's Oncology Group. Cancer 118 (19): 4806-14, 2012. [PUBMED Abstract]
- Lange BJ, Kobrinsky N, Barnard DR, et al.: Distinctive demography, biology, and outcome of acute myeloid leukemia and myelodysplastic syndrome in children with Down syndrome: Children's Cancer Group Studies 2861 and 2891. Blood 91 (2): 608-15, 1998. [PUBMED Abstract]
- Creutzig U, Reinhardt D, Diekamp S, et al.: AML patients with Down syndrome have a high cure rate with AML-BFM therapy with reduced dose intensity. Leukemia 19 (8): 1355-60, 2005. [PUBMED Abstract]
- Blink M, Zimmermann M, von Neuhoff C, et al.: Normal karyotype is a poor prognostic factor in myeloid leukemia of Down syndrome: a retrospective, international study. Haematologica 99 (2): 299-307, 2014. [PUBMED Abstract]
- Craze JL, Harrison G, Wheatley K, et al.: Improved outcome of acute myeloid leukaemia in Down's syndrome. Arch Dis Child 81 (1): 32-7, 1999. [PUBMED Abstract]
- Gamis AS, Woods WG, Alonzo TA, et al.: Increased age at diagnosis has a significantly negative effect on outcome in children with Down syndrome and acute myeloid leukemia: a report from the Children's Cancer Group Study 2891. J Clin Oncol 21 (18): 3415-22, 2003. [PUBMED Abstract]
- Zeller B, Gustafsson G, Forestier E, et al.: Acute leukaemia in children with Down syndrome: a population-based Nordic study. Br J Haematol 128 (6): 797-804, 2005. [PUBMED Abstract]
- Taga T, Shimomura Y, Horikoshi Y, et al.: Continuous and high-dose cytarabine combined chemotherapy in children with down syndrome and acute myeloid leukemia: Report from the Japanese children's cancer and leukemia study group (JCCLSG) AML 9805 down study. Pediatr Blood Cancer 57 (1): 36-40, 2011. [PUBMED Abstract]