[1275] Trisomy 11 as a Sole Abnormality in Acute Myeloid Leukmia and Myelodysplastic Syndrome has Unfavorable Prognosis but No Association with Mutations of Kit and RAS Genes

FM Alseraye, Z Zuo, CE Bueso-Ramos, LJ Medeiros, FH Barakat, G Lu. M.D. Anderson Cancer Center, Houston, TX

Background: Trisomy 11 (+11) as a sole cytogenetic abnormality is a rare, recurrent event in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). The occurrence of this abnormality as a sole cytogenetic abnormality in AML has been associated with poor prognosis. The goal of this study was to collect cases of AML and MDS with +11 as a sole cytogenetic abnormality to assess their clinicopathologic features and correlate with the result of other molecular tests performed on this cohort.
Design: We searched the cytogenetic database at our institute for isolated +11 in AML and MDS over a period of 11 years. Clinical, morphologic and flow cytometric data were reviewed.We preformed molecular studies to assess c-Kit, RAS, and FLT3 molecular aberrations.
Results: A total of 18 cases with +11 as the sole abnormality at diagnosis were found, including 14 AML and 4 MDS. There were 12 men and 6 women. The median age was 69 years(range 33-98). Eleven patients (60%) were over the age of 60 years. Clinical follow up was available in 16 patients. All 4 MDS patients developed AML, with 3 occurring in less than 6 months. Fifteen patients had a progressive clinical course with refractory/relapse disease. Survival ranged from 5 months ∼ 4 years. Only one patient showed complete remission after chemotherapy/stem cell transplantation. Ten patients were diagnosed with AML, FAB-M1 subtype, 4 patients had M2, two patients had M0. Subtypes of M5a, and M6 each was also found in 2 patients. Blast count in bone marrow was higher than 50% in 14 of 18 patients. Immunophenotyping by flow cytometry showed consistent expression for a stem cell phenotype including CD34, HLA-DR, CD13, CD13. FLT3-ITD was present in 7 cases (40%). C-Kit and RAS mutations were absent in all cases assessed.
Conclusions: Our study further confirms that isolated trisomy 11 in AML is associated with poor prognosis as previously reported and it is not restricted to a specific morphology; however, there is a tendency for FAB-M1 subtype. Although mutations of c-Kit and RAS are common in AML, they were not identified in this study.
Category: Hematopathology

Wednesday, March 24, 2010 1:00 PM

Poster Session VI # 189, Wednesday Afternoon


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