The incidence and the effect of translocations t(15;17), t(8;21), inv(16), t(9;22) on prognosis in our patients with acute myeloid leukemia

Background and Aim: Acute myeloid leukemia (AML) is a heterogenous clonal malignancy of haematopoietic stem cells, has a increased incidence with age. Differentiation capability is being lost in these growing stem cell clone, and resulted with depressed normal haematopoiesis. The diagnosis based on detection of increased immatur blastic cells in bone marrow higher than 20%. Molecular, cytogenetic and previous haematologic disease constitute the main of the WHO classification. More than a hundered cytogenetic defect has been determined. However, the most often chromosomal abnormalities were t(8;21), t(15;17), inv(16) and t(16;16). Patients with t(8;21), inv(16) or t(15;17) have relatively good, and with t(9;22) have relatively poor prognosis. In this presented study, we investigate the incidence and impact of these most common chromosomal abnormalities on prognosis of patients with newly diagnosed AML.Material and Methods: Totally 82 consecutive patients with AML who admitted to Dicle University, Faculty of Medicine, Department of Haematology were included into the study. These most common chromosomal abnormalities, t(8;21), t(15;17), inv(16) and t(9;22) were studied with Real Time PCR (Roche-lightCycler).Findings: In our study, the incidence of t(8;21) was 6%, of t(15,17) was 17%, of inv(16) was 9.7%. t(9;22) was not detected in any of patients with AML. All patients with t(15;17) positivity were treated with ATRA-Ida protocole. Remission was achieved in all of them, and any of them did not relapsed. t(15;17) was disappeared in all of these patients during follow up period. A significant difference was found between t(8;21) positive and negative groups in terms of relapse. We did not find any difference between t(8;21) positive and negative groups in terms of refractoriness, overall response and overall survey. Similarly, there was no statistically significant difference in relaps rate, refractoriness, overall response and survey of patients with inv16 positive and negative patients. Patients with good prognostic chromosomal abnormalities (patients with t(8;21) or inv(16)) were significantly different from others in terms of development of relapse. However, there were no statistically significant difference in terms of refractoriness, overall response and survey between these groups.Conclusion: Chromosomal abnormalities which effect the prognosis of the disease should be investigated in all newly diagnosed AML cases. In addition, complete caryotypical analysis should be performed to determine additional chromosomal abnormalities, and to consider different treatment options, and thought about prognosis. Larger scale studies needed to determine the importance of additional chromosomal abnormalities.Key words: Acute miyeloid leukemia, t(15;17), t(8;21), inv16, t(9;22)