[1381] Acquired Trisomy 21 as a Sole Chromosomal Abnormality Is Associated with a Heterogeneous Group of Myeloid Neoplasms and Variable Disease Outcome

Su S Chen, C Cameron Yin, Sergej N Konoplev, Ken H Young, Ramya Muddasani, L Jeffrey Medeiros, Gary Lu. University of Texas MD Anderson Cancer Center, Houston, TX

Background: Trisomy 21 (+21) is a common trisomy in myeloid neoplasms, and is typically associated with other numerical and/or structural chromosomal abnormalities that have prognostic significance. Trisomy 21 as a sole cytogenetic abnormality is rare and its role in the pathogenesis of myeloid neoplasms is unclear. We studied the clinicopathologic and molecular features of 40 patients with myeloid neoplasms associated with isolated +21.
Design: Myeloid neoplasms in bone marrow with isolated +21 were collected from the database of our institution. Clinical and other laboratory data were collected by review of the medical records. Myeloid neoplasms were diagnosed and categorized based on the 2008 World Health Organization (WHO) classification.
Results: We identified 40 patients with isolated +21, including 23 (57.5%) acute myeloid leukemia (AML), 15 (37.5%) myelodysplastic syndromes (MDS), and 2 (5%) myelodysplastic/myeloproliferative neoplasms (MDS/MPN). The median age was 62 years (range, 39-88) and there were 26 males and 14 females. The AML cases were classified as: AML with myelodysplasia related changes (n=7), acute myelomonocytic leukemia (n=3), acute monocytic leukemia (n=2), AML with maturation (n=2), therapy-related AML (n=1), mixed phenotype acute leukemia, B/myeloid, NOS (n=1), and AML, NOS (n=7). The median bone marrow blast count was 41% (range, 4-82), median peripheral white blood cell count 29 x 109/L (range, 1-133), median hemoglobin 9.0g/dL (range, 8-12), and median platelet count 74 x 109/L (range, 13-325). Genetic analysis showed FLT3 mutation in 4/18 (22.2%), NPM1 mutation in 1/5 (20%), RAS mutation in 3/17 (17.6%), KIT mutation in 0/6 (0%). Complete remission was achieved in 17/21 (80.9%) patients with follow-up. The median overall survival was16 months (range, 0-164). The MDS cases were classified as: refractory anemia with excess blasts-2 (n=6), refractory anemia with excess blasts-1 (n=1), refractory cytopenia with multilineage dysplasia (n=4), therapy related-MDS (n=1), and MDS, NOS (n=3). The median diagnostic bone marrow blast count was 3% (range, 0-15). Genetic analysis showed FLT3 mutation in 0/13 (0%), NPM1 mutation in 0/3 (0%), RAS mutation in 1/14 (7%), and KIT mutation in 0/3 (0%). The median overall survival was 27 months (range, 6-48).
Conclusions: Trisomy 21 as a sole chromosomal abnormality is associated with a heterogeneous group of myeloid neoplasms including AML and MDS of various types as well as MDS/MPN.
Category: Hematopathology

Tuesday, March 20, 2012 9:30 AM

Poster Session III # 212, Tuesday Morning


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