Background :
Acute myelod leukemia (AML) is a hematologic malignant disease characterized by uncontrolled proliferation of myeloid cells in marrow and arrest in their maturation. It accounts for 70∼80% of chromosomal abnormalities and
t(8;21) has been found in 40% of AML-M2. Because cytogenetic studies can help classifying the disease, providing the clues of disease progression and monitoring remission after chemotherapy, we have performed cytogenetic studies to identify the incidence of t(8;21) and other chromosomal abnormalities and to assure their prognostic significance in patients with AML-M2.
Methods : From August 1998 to July 2000, 38 patients with AML-M2 were treated with ara- C and idarubicin in order to induce complete remission. We evaluated chromosomal abnormalities by high resolution banding technique. We divided patients
into 3 groups. Patients having normal and intermediate risk karyotype belonged to group A, t(8;21) to group B and, unfavorable and undetermined prognostic karyotype to group C.
Results :
The incidence of chromosomal abnormalities was 71% (27/38), and the proportion of A, B, and C group were 40%, 30% and 30%, respectively. The median follow up duration of evaluable patients was 381 (55∼1,295) days. The complete
remission (CR) rate accounted for 79% (30/38). The CR rate in A, B and C group were 88% (14/16), 91% (10/ 11) and 55% (6/11), respectively (P=0.06). The median remission duration had not been reached yet. The median remission duration of group A and B had not been reached yet, but that of group C was 337 days (P=0.60). The overall median survival duration was 567 days, and the median survival duration of group B had not been reached yet, otherwise those that of group A and C were 432 days and 364
days, respectively (P=0.02).
Conclusion :
The incidence of chromosomal abnormalities was observed 71% in patients with AML-M2. The patients with t(8;21) showed higher complete remission rate and tendency to have longer remission duration and survival duration.

Keywords: Chromosomal abnormality, Acute myeloid leukemia, t(8,21)