| The incidence and development of tumors which maybe closely related to cytogenetic abnormalities. Acute myeloid leukemia (AML) is right a malignant tumor of hemopoietic system. It has been studied that the majority of patients with leukemia have non-random chromosome aberrations which may provide important information for typing, prognostic evaluation, options of treatment, and even the researches of pathogenesis. The purpose of this article is to study the distribution of karyotype and the relationship between chromosome abnormalities and prognostic in AML according to known domestic and international hierarchical cytogenetic classification. Karyotype analysis of 132 cases which were newly diagnosed as AML (excluding patients with acute promyelocytic leukemia) in our hospital from January 2001 to June 2006 were performed. The clinical data and survival state of 101 cases with induction therapy were recorded through a follow-up. Kaplan-Meier life-tables were constructed for survival data and were compared by means of the Log-rank test. Cox regression was used to analysis the several possible factors influencing survival of AML. The result shows: (1) In this study M2 is the most common type of AML. 82 patients presented clonal chromosome abnormalities, and rate of abnormality is 62.1%. (2) Forty-two kind of abnormalities were observed, including simply structural abnormalities, simply numerical abnormalities and compound abnormalities. The proportion of the three groups above are 41.5%, 28%, and 30.5% respectively. t (8; 21) (q22; q22) is the most common structural rearrangement, and rate is 28.8%. Inv (16)/del (16q), +21, -7, del (9q) are also observed frequently. (3) 101 patients with induction therapy were categorized into favorable, intermediate, unfavorable and unknown risk groups based on SWOG coding. Median overall survive time varied significantly between unfavorable risk group and all other three groups. There was similar significant heterogeneity of median disease-free survival time. Although there was no statistical difference in CR rates. (4) These 101 patients were also categorized into seven subgroups based on different hierarchical cytogenetic classifications. CR rate varied significantly between the simply t (8; 21) group and the t (8; 21) additional group without del (9q) and complex abnormalities, also between the latter and intermediate risk group. Median overall survive time varied significantly between the unfavorable risk group without t (8; 21) [del(9q), complex abnormalities without t (8; 21), -7] and all other six groups. (5) Median survival time was longer in the group with finally achieving complete remission (HR=0.0147). In the light of the analysis above, we can come to the following conclusions: (1) The rate of chromosome abnormalities is 62.1%. The kinds of cytogenetic abnormalities are varies, but structure abnormality is primary. Some abnormalities have been invariably associated with a specific FAB group; (2) Cytogenetic analysis is recognized as an important prognostic factor in acute leukemia. In this study, group with inv (16) /del (16q) has an superior CR and OS to others; The overall survival time of unfavorable risk group without t (8; 21) [del (9q), complex abnormalities without t (8; 21), -7] is shorter than others; (3) The simply t (8; 21) group has an superior CR to the t (8; 21) additional group without del (9q) and complex abnormalities. There was no statistical difference in survival time between intermediate risk group and group with t (8; 21), regardless of additional cytogenetic abnormalities. However, the overall survival time of the simply t (8; 21) group is longer. With the expansion of the sample, the simple t (8;21) group may be better than the t (8; 21) additional group. |
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