Abstract:

Objective To analyze the significance of minimal residual disease（MRD）dynamic monitoring in the prognosis of acute B-lymphoblastic leukemia（B-ALL） children with positive and negative ETV6/RUNX1 fusion genes. Methods The clinical data of 234 children with B-ALL in the Children's Hospital of Zhengzhou University from January 2018 to June 2021 were collected. There were 78 children with ETV6/RUNX1 fusion gene（positive group） and 156 children without ETV6/RUNX1 fusion gene（negative group）. The differences in relapse-free survival（RFS） between positive and negative groups were compared. The results of MRD in the 2 groups on the 15th day（MRD1） and the 33rd day（MRD2） of induction chemotherapy and before the start of consolidation therapy（the 12th week，MRD3） were calculated，and the significance of MRD1，MRD2 and MRD3 in the prognosis of B-ALL children was analyzed. Results Compared with negative group，the RFS in positive group were prolonged（P=0.029）. In negative group，there was no statistical significance in RFS between MRD1 negative and positive children（P>0.05），but the RFS of MRD2 and MRD3 negative children were longer than those of MRD2 and MRD3 positive children（P<0.05），and MRD3 was an independent risk factor for RFS odds ratio was 3.678， 95% confidence interval 1.254-10.785，P=0.018）. In positive group，there was no statistical significance in RFS between MRD1 and MRD2 positive and negative children（P>0.05），but the RFS of MRD3 negative children was longer than those of MRD3 positive children，but MRD3 was not an independent risk factor for RFS（P>0.05）. Conclusions MRD dynamic monitoring has prognostic significance for B-ALL children with negative ETV6/RUNX1 fusion gene，and MRD dynamic monitoring should be carried out. For positive ETV6/RUNX1 fusion gene children，the significance of MRD dynamic monitoring is weak. Clinic can decide whether to use according to actual situation.

Key words: Minimal residual disease, Acute B-lymphoblastic leukemia, ETV6/RUNX1 fusion gene, Flow cytometry, Prognosis