A Clinical Analysis Of Acute Myeloid Leukemia With Inv(3)/t(3;3)

Purpose:The clinical and biological features of AML with inv(3)(q21q26) or t(3;3)(q21q26) are still uncertain, and no systematic study has been undertaken in large series of Chinese patients until recently.Method:This study analyzed 25 cases of AML with inv(3)/t(3;3) from 12 institutions in the east of China. And we collected 70 non-APL patients without inv(3)/t(3;3) as control. We analyzed age, gender, WBC count, hemoglobin concentration, platelet count, morphological evaluation, cytogenetic study, gene mutation and flow Cytometry Immunophenotyping using T-test or chi-square test. The survival analysis was carried out with Kaplan-Meier analysis.Result:1. In our study group, the media age was 44 years, sex ratio(male/female) was 0.786, there were no differences between study group and the control. The hemoglobin concentrations, platelet count, white blood count was 73g/1,357×109/L and 15.5 X 109/L respectfully when newly diagnosed. Compared with the control group, the AML patients with inv(3)/t(3;3)were more likely to have higher platelet count.2. M4 and M5 were the most common type of AML patients with inv(3)/t(3;3) which is similar to the control. And we figure out that BM myeloid dysplasia in our group were observed in 81.3% of the de no AML in the research, BM erythroid dysplasia covered 87.5%, and megakaryocytic dysplasia, including micromegakaryocytes, was found in all the cases.3. In our series, the expression the immature markers CD34 and HLA-DR is higher than the control, no difference in the myeloid markers shows between the study group and the control. Only a few inv(3)/t(3;3)-AML express CD41, which is marker of inv(3)/t(3;3)-AML. CD7 can be found in 38.5% in the study group. No other lymphocyte related marker was observed in inv(3)/t(3;3)-AML.4. Monosomy 7 is the most common additional karyotypic abnormalities which is higher than the control. Other karyotypic abnormalities have no difference between the two group. EVI1 expression can be observed in all patients of AML-inv(3)/t(3;3) group, no other gene abnormality was found. As limiting of the sample size of the study group, the difference of the gene mutation can’t be compared.5. By Kaplan-Meier analysis,the AML patients with Inv(3)/t(3;3) had shorter overall survival times than the other types. And de novo AML-Inv(3)/t(3;3) had poorer prognosis compared with the secondary ones.Conclusion:This showed that AML with inv(3)/t(3;3) often elevated platelet counts at the initial diagnosis, hyperplasia with dysplasia of megakaryocytes, poor prognosis, and bone marrow (BM) transplantation maybe had a low curative potential. And studies involving leukemia with the special karyotype should help unfold the characteristics of this disease.