Measurable residual disease-based strategy and reduced-intensity
hematopoietic stem cell transplantation for acute myelogenous leukemia
in children
Abstract
Background. Measurable residual disease (MRD) is a powerful prognostic
factor in patients with acute myelogenous leukemia (AML). We previously
conducted a prospective study on an MRD-based strategy for the treatment
of children with AML, and its significance has been reported. The
present retrospective study is a pooled analysis of 34 patients who were
registered after the completion of the previous study. Procedure.
Reduced-intensity conditioning (RIC) followed by allogeneic
hematopoietic stem cell transplantation (RIC-HSCT) was adopted to
increase survival rates and minimize toxicities. The strategy was also
refined with a minor modification, with WT1 expression levels in
peripheral blood, as an MRD marker after a 2nd course of chemotherapy
(consolidation course 1), being measured in addition to WT1, chimeric
mRNA, and aberrant surface markers in bone marrow. Results. Five-year
relapse-free and overall survival rates were 76.5 and 85.2%,
respectively. RIC-HSCT was safely and effectively performed on
MRD-positive patients. Among patients who underwent RIC-HSCT,
re-emerging/rising MRD and high levels of MRD before HSCT were risk
factors for disease relapse early after HSCT. Conclusions. The MRD-based
strategy and RIC-HSCT worked well for children with AML.
HLA-haploidentical peripheral blood transplantation following RIC may be
a promising candidate for further study on patients at very high risk of
relapse.