Minimal residual disease evaluation in childhood acute lymphoblastic leukemia

If levels of minimal residual disease are high at the end of the first or second phases of treatment in newly diagnosed patients, at the end of the first phase of treatment for relapsed patients, and before a stem cell transplant, patients are more likely to relapse. [...] In this study, more than 2,000 patients with precursor-B ALL (precursor B-cell) were enrolled between 2000 and 2005 and had MRD evaluated in bone marrow at the end of induction and again at the end of consolidation, as well as in the peripheral blood on Day 8 after the start of treatment. [...] In 2014, the Foundation for the National Institutes of Health and partners including the National Cancer Institute launched an MRD study that includes undertaking standardization of flow cytometric measurement of MRD across North America, and will be coordinated with the Children’s Oncology Group program to transition its MRD measurements to a new laboratory service model.28 The POGO MRD Working G [...] Finally, three main factors that can raise the quality of evidence were considered: the large magnitude of effect, the dose-response gradient, and any residual confounding factors.52 For more detailed information, please refer to the latest series of GRADE articles.52 The GRADE Working Group adapted considerations of the above GRADE domains.53 This GRADE guidance was used for evaluating the qualit [...] Most studies used PCR techniques for MRD evaluation; only two used flow cytometry.57,62,64,66 The quantitative range (i.e., lowest sensitivity of detection) of the assays in the studies were all on the order of 10−4 (i.e., 1 in 10,000 cells), with the minimum detection of 10−3 (i.e., 1 in 1,000 cells).