Predictive Factors of Response and Survival Following Chemotherapy Treatment In Acute Leukemia with Complex Karyotype Aberrations

Abstract 4857 Background: Acute leukemia (AL) is a clonal hematopoietic stem cell disorder with diverse genetic abnormalities and various responses to treatment. AL was categorized into favorable, intermediate and adverse karyotype according to cytogenetic characteristics comprising different groups of patients with similar treatment response, relapse risk and overall survival. In particular, Patients with complex chromosome aberrations (CCA) harboring three or more acquired chromosome aberrations always have poor outcomes. It is necessary to investigate the clinical and laboratory features of AL patients with CCA, and to explore the underlying mechanisms of leukemogenesis in order to improve prognosis in these patients. Methods: 83 AL patients with CAA were investigated and other 83 AL patients with none-complex chromosome aberrations (N-CCA) were regarded as control group from January 2005 to August 2008. The diagnosis of AL was based on morphological picture, immunophenotypical analysis, and cytochemical studies and FAB criteria were used for AL subtype classifications. Karyotypes were also analysed using conventional G-banding method. After patients had comfirmed diagnosis with AL, corresponding induction and consolidation chemotherapy in the two groups were given. Finally the treatment efficacy and prognosis were assessed. All the statistical analyses were performed using Kaplan-Meier. Results: There was no significant difference about sex, age and peripheral blood parameters before treatment between AL patients with CAA and the control group during the same period (p>0.05). CD34 was expressed in 72.3% of the AL patients with CCA, significantly higher than that in the control group (37.4%)(p<0.01). CD34+ AL patients with CCA showed a lower complete remission (CR) rate than in CD34- cases (p<0.05). 3-years EFS and OS were shorter in CD34+ patients than in CD34- cases. Using Kaplan-Meier analysis, the median survival time of AL patients with CCA was only 9 months, significantly shorter than the control group (21.5 months). There was no significant difference between AML and ALL patients with complex chromosome aberrations about CR rate and the survive time. Conclusion: The prognosis of patients with complex karyotype who received chemotherapy was extremely poor. In view of this, such patients should be considered as a unique entity and separated from those with a non-complex adverse cytogenetic change. They maybe benefit to some extent from allogeneic stem cell transplantation in younger patients according to some related reports. CD34 was associated with CAA while the underlying mechanisms between them were unknown. Disclosures: No relevant conflicts of interest to declare.