Purpose Although outcomes of
children with
acute myeloid leukemia (AML) have improved over the last decades, around one-third of
patients relapse . Measurable (or minimal) residual
disease (MRD)
monitoring may guide
therapy adjustments or pre-emptive
treatments before overt hematological
relapse .
Methods In this study, we
review 297
bone marrow samples from 20 real-
life pediatric AML
patients using three MRD
monitoring methods: multiparametric
flow cytometry (MFC),
fluorescent in situ hybridization (FISH) and
polymerase chain reaction (
PCR ). Results
Patients showed a 3-year overall
survival of 73% and a 3-year
event-free survival of 68%. Global
relapse rate was of 25%. All
relapses were preceded by the reappearance of MRD
detection by (1) MFC (p = 0.001), (2)
PCR and/or FISH in
patients with an identifiable
chromosomal translocation (p = 0.03) and/or (3) one log increase of
Wilms tumor gene 1 (WT1) expression in two consecutive samples (p = 0.02). The median times from MRD
detection to
relapse were 26, 111, and 140 days for MFC, specific
PCR and FISH, and a one log increment of WT1, respectively. Conclusions MFC, FISH and
PCR are complementary
methods that can anticipate
relapse of childhood AML by weeks to several months. However, in our series, pre-emptive
therapies were not able to prevent
disease progression . Therefore, more sensitive MRD
monitoring methods that further anticipate
relapse and more effective pre-emptive
therapies are needed (AU)