%0 Journal Article
%T Flow cytometric minimal residual disease measurement accounting for cytogenetics in children with non-high-risk acute lymphoblastic leukemia treated according to the ALL-MB 2008 protocol.
%A Popov A
%A Henze G
%A Tsaur G
%A Budanov O
%A Roumiantseva J
%A Belevtsev M
%A Verzhbitskaya T
%A Movchan L
%A Lagoyko S
%A Zharikova L
%A Olshanskaya Y
%A Riger T
%A Valochnik A
%A Miakova N
%A Litvinov D
%A Khlebnikova O
%A Streneva O
%A Stolyarova E
%A Ponomareva N
%A Novichkova G
%A Aleinikova O
%A Fechina L
%A Karachunskiy A
%J Cancer Med
%V 13
%N 8
%D 2024 Apr
%M 38651186
%F 4.711
%R 10.1002/cam4.7172
%X <B>BACKGROUND: </B>Quantitative measurement of minimal residual disease (MRD) is the "gold standard" for estimating the response to therapy in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Nevertheless, the speed of the MRD response differs for different cytogenetic subgroups. Here we present results of MRD measurement in children with BCP-ALL, in terms of genetic subgroups with relation to clinically defined risk groups.<BR><B>METHODS: </B>A total of 485 children with non-high-risk BCP-ALL with available cytogenetic data and MRD studied at the end-of-induction (EOI) by multicolor flow cytometry (MFC) were included. All patients were treated with standard-risk (SR) of intermediate-risk (ImR) regimens of "ALL-MB 2008" reduced-intensity protocol.<BR><B>CONCLUSIONS: </B>Among all study group patients, 203 were found to have low-risk cytogenetics (ETV6::RUNX1 or high hyperdiploidy), while remaining 282 children were classified in intermediate cytogenetic risk group. For the patients with favorable and intermediate risk cytogenetics, the most significant thresholds for MFC-MRD values were different: 0.03% and 0.04% respectively. Nevertheless, the most meaningful thresholds were different for clinically defined SR and ImR groups. For the SR group, irrespective to presence/absence of favorable genetic lesions, MFC-MRD threshold of 0.1% was the most clinically valuable, although for ImR group the most informative thresholds were different in patients from low-(0.03%) and intermediate (0.01%) cytogenetic risk groups.<BR><B>CONCLUSIONS: </B>Our data show that combining clinical risk factors with MFC-MRD measurement is the most useful tool for risk group stratification of children with BCP-ALL in the reduced-intensity protocols. However, this algorithm can be supplemented with cytogenetic data for part of the ImR group.