Clinical Significance of the Chromosomal Abnormalities and Immunophenotype in Acute Myeloid Leukemia

Kwon, Hyuk Chan

Abstract

BACKGROUND: Acute myeloid leukemia (AML) is a hematologic malignant disease characterized by an uncontrolled proliferation of myeloid cells in marrow and arrest in their maturation. Immunophenotyping is a widely used method to diagnose and classify leukemia, and cytogenetic studies can help providing the clues of disease progression and monitoring remission status after chemotherapy.
METHODS
From August 1997 to July 2000, 68 patients with AML were treated with ara-C and idarubicin for remission induction, then followed by consolidation therapy. A panel of monoclonal antibodies (CD5, CD7, CD10, CD19, CD22, CD14, CD13, CD33, HLA-DR) were used to characterize immunologic phenotypes by flow cytometry. Chromosomal abnormalities by high resolution banding technique were evaluated. Patients were divided into three groups (favorable : A, intermediate : B, unfavorable : C).
RESULTS
The incidence of chromosomal abnormalities was 57% (39/68), and the proportion of patients per groups were 21% (14/68) for group A, 57% (39/68) for group B, and 22% (15/68) for group C. The median follow- up duration of the 68 evaluable patients was 12.7 months. The complete remission (CR) rate was 63.2% (43/68). The CR rate in group A, B, and C were 92.9% (13/14), 66.7% (26/39) and 26.7% (4/15), respectively (P=0.005). The AML patients who expressed CD19 (P=0.048) or did not express CD14 (P=0.013) had better CR than other groups. The median leukemia free survival duration of group A and B were 39.5 months and 11.9 months, respectively, and the leukemia free survival duration of group C has not been reached at median value (P=0.038). The median overall survival duration was 12.3 months, the survival duration of group A has not been reached at median value, and the median survival duration of group B and C were 12.0 months and 1.5 months, respectively (P=0.001). The AML patients without CD7 (P=0.029), without CD14 (P=0.023), or with CD19 (P=0.047) showed a better survival than other groups. In multivariate analysis, karyotype proved to be a significant prognostic factor (P=0.018).
CONCLUSION
This study demonstrated that karyotype was an important prognostic factor in AML patients. Among surface marker expressions, CD7, CD14, CD19 may be used as a prognostic factor. Further study will be needed to confirm the role of immunophenotyping in AML.