1. SIGNIFICANCE OF ETV6-RUNX1 FUSION GENE TRANSCRIPT DETECTION IN PEDIATRIC B-CELL PRECURSOR ACUTE LYMPHOBLASTIC LEUKEMIA WITH TRANSLOCATION t(12;21)(p13;q22)
- Author
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G. A. Tsaur, Т. О. Riger, A. M. Popov, T. Yu. Verzhbitskaya, L. V. Vakhonina, A. A. Vlasova, Yu. V. Olshanskaya, А. N. Kazakova, O. V. Streneva, O. V. Makarova, S. V. Tsvirenko, L. I. Saveliev, О. R. Arakaev, and L. G. Fechina
- Subjects
acute lymphoblastic leukemia ,children ,minimal residual disease ,translocation t(12 ,21)(p13 ,q22) ,etv6-runx1 fusion gene transcript ,Diseases of the blood and blood-forming organs ,RC633-647.5 - Abstract
Introduction. Translocation t(12;21)(p13;q22) is one of the most common structural genetic abnormalities in childhood acute lymphoblastic leukemia (ALL). It cannot be detected by conventional G-banding, so a reverse-transcriptase polymerase chain reaction (RT-PCR) or fluorescent in situ hybridization are used for this purpose.The aim of the study was to evaluate the prognostic significance of qualitative and quantitative detection of ETV6-RUNX1 fusion gene transcript at various time points in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL) patients.Materials and methods. ETV6-RUNX1 fusion gene transcript was revealed by both reverse-transcriptase PCR and quantitative real-time PCR (RQ-PCR) in 34 out of 166 (20.5 %) children with BCP-ALL. Qualitative ETV6-RUNX1-positivity at days 36 and 85 led to unfavorable outcome (lower event-free survival –EFS and higher cumulative incidence of relapse – CIR). While ETV6-RUNX1 status at day 15 did not allow to divide patients with different outcomes. By ROC curve analysis we determined threshold levels (TL) for ETV6-RUNX1/ABL1 ratio at days 0, 15, 36 and 85. Afterwards we adjusted obtained results to 10-fold scale.Results. So practically applicable TL were as follows 500.0 %, 1 %, 0.1 % и 0.01 % for days 0, 15, 36 and 85, respectively. EFS and CIR were both worse in patients with ETV6-RUNX1/ABL1 ratio equal or above defined TL. Moreover, initial ratio ≥500,0 % corresponded to delayed blast clearance at days 15 and 36. We showed good qualitative (84.8 %) and quantitative (R2 = 0.953) concordance between ETV6-RUNX1/ABL1 ratio and MRD data obtained by flow cytometry at days 15, 36, 85. Of note, defined TL for ETV6-RUNX1/ABL1 at days 15, 36, 85 were equal to prognostically important levels for flow cytometry MRD.Conclusion. Thus, qualitative detection and quantitative value of ETV6-RUNX1 fusion gene transcript showed prognostic significance in the course of treatment in children with BCP-ALL. Based on these results we propose standardization approaches for Moscow – Berlin ALL study group.
- Published
- 2018
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