Impact of Dysplasia on Outcome of Patients with Acute Myeloid Leukemia and Response to Allogeneic Hematopoetic Stem Cell Transplant

Background: Myelodysplastic syndromes (MDS) are a heterogeneous group of malignancies characterized by dysplasia, cytopenia, ineffective hematopoiesis and by an increased risk of transformation to acute myeloid leukemia (AML). Recurrent aberrant karyotypes cannot entirely account for the genetic defects that are at the basis of the pathogenesis of MDS, as they are detected only in approximately 50% of patients.

Allogeneic hematopoietic cell transplantation (HCT) likely prolongs survival in patients with AML and MDS. In this report, we evaluated the impact of presence of dyspoesis in paients with AML with or without cytogenetic (CG) abnormality on outcome in our center.

Methods: We retrospectively reviewed all patients who were diagnosed with AML (non promyelocytic) in our center between 2002 and 2012. Primary objective was to study the impact of MDS with or without CG abnormalities on outcome of patients with AML. Demographics and disease-related variables were collected. OS was defined as the time from diagnosis to the time of death or last contact.

Results: Between 2002 and 2012, 123 patients with high or intermediate risk AML patients were treated at our center. Median age at diagnosis was 60 (range 19-89). Median OS for all patients was 368 days. Of 123 patients, 51 had MDS while 73 did not. CG abnormalities were present in 35 (68%) of patients with dyspoetic changes. Median age of AML patients with MDS was 59 while median age of AML without MDS patients was 55. Median number of blasts in bone marrow and peripheral blood in AML patients with MDS was 38% and 6% respectively. While median number of blasts in bone marrow and peripheral blood in AML patients without MDS was 67% and 39% respectively. Of 51 AML patients with MDS, 14 received HCT with median age of 56. Half of these received myeloablative regimen while the other half received reduced toxicity regimen.

The median survival time for AML patients without MDS was 401 days while the median survival time for AML patients with MDS was 278 days (p = 0.0201), Fig1. 

For AML with MDS who received HCT, the median survival time was 586 days while it was 164.5 days for AML patient with MDS who did not receive HCT (p = 0.0013), Fig2.

Conclusion: In this small cohort from a single center, the results suggest that AML patients with dyspoetic changes do have a worse prognosis despite having lower percentage of blasts in bone marrow or peripheral blood. This can be explained by what Walter et al reprted, using next-generation sequencing, that the proportion of neoplastic marrow cells is indistinguishable in MDS and secondary-AML even with myeloblast count of zero. HCT can be performed in those patients including older patients with promising results.

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