Minimal residual disease monitoring via AML1-ETO breakpoint tracing in childhood acute myeloid leukemia

Relapse of childhood AML1-ETO (AE) acute myeloid leukemia is the most common cause of treatment failure. Optimized minimal residual disease monitoring methods is required to prevent relapse. In this study, we used next-generation sequencing to identify the breakpoints in the fusion gene and the DNA-based droplet digital PCR (ddPCR) method was used for dynamic monitoring of AE-DNA. The ddPCR technique provides more sensitive and precise quantitation of the AE gene during disease progression and relapse. Quantification of the AE fusion gene by ddPCR further contributes to improved prognosis. Our study provides valuable methods for dynamic surveillance of AE fusion DNA and assistance in determining the prognosis

Gene expression prognostic of early relapse risk in low‐risk B‐cell acute lymphoblastic leukaemia in children

Abstract ETV6::RUNX1 is the most common fusion gene in childhood acute lymphoblastic leukaemia (ALL) and is associated with favorable outcomes, especially in low‐risk children. However, as many as 10% of children relapse within 3 years, and such early relapses have poor survival. Identifying children at risk for early relapse is an important challenge. We interrogated data from 87 children with low‐risk ETV6::RUNX1‐positive B‐cell ALL and with available preserved bone marrow samples (discovery cohort). We profiled somatic point mutations in a panel of 559 genes and genome‐wide transcriptome and single‐nucleotide variants. We found high TIMD4 expression (> 85th‐percentile value) at diagnosis was the most important independent prognostic factor of early relapse (hazard ratio [HR] = 5.07 [1.76, 14.62]; p = 0.03). In an independent validation cohort of low‐risk ETV6::RUNX1‐positive B‐cell ALL (N = 68) high TIMD4 expression at diagnosis had an HR = 4.78 [1.07, 21.36] (p = 0.04) for early relapse. In another validation cohort including 78 children with low‐risk ETV6::RUNX1‐negative B‐cell ALL, high TIMD4 expression at diagnosis had an HR = 3.93 [1.31, 11.79] (p = 0.01). Our results suggest high TIMD4 expression at diagnosis in low‐risk B‐cell ALL in children might be associated with high risk for early relapse