Abstract
Background: FAB-M4 and M5 are unique subgroups of pediatric acute myeloid leukemia. However, for these patients, few studies have demonstrated the clinical and biological characteristics and efficacy of hematopoietic stem cell transplantation (HSCT), and especially haplo-HSCT. Procedure: We retrospectively evaluated the outcomes of 70 children with FAB-M4/M5 enrolled in our center from January 2013 to December 2017. Results: Of the patients, 32, 23, and 15 were in low-risk, intermediate-risk, and high-risk groups, respectively. T(16;16), inv16/CBFB-MYH11 was the most frequent cytogenetic abnormality. Among detected genetic alterations, WT1 was mutated at the highest frequency, followed by FLT3-ITD, NPM1, and CEBPA. Thirty-three patients received HSCT (haplo-HSCT = 30), of which four, 18, and 11 were in low-risk, intermediate-risk, and high-risk groups, respectively. For all patients, the 3-year overall survival (OS), event-free survival (EFS), and cumulative incidence of relapse (CIR) were 85.3 ± 4.3%, 69.0 ± 5.7%, and 27.9 ± 5.2%, respectively. By multivariate analysis, low-risk stratification predicted superior OS, EFS, and PLT ≤ 50 × 109/L at diagnosis, with FLT3-ITD mutations predicting higher CIR and poorer EFS. In intermediate- and high-risk groups, HSCT was independently associated with higher EFS and lower CIR. With a median post-transplant observation time of 30.0 months, the 3-year OS, EFS, CIR, and non-relapse mortality in the haplo-HSCT group were 74.2 ± 8.6%, 68.3 ± 8.9, 24.6 ± 7.6%, and 6.6 ± 4.1%, respectively. Conclusions: Risk-oriented treatment is important for pediatric FAB-M4/M5. For intermediate- and high-risk groups, HSCT significantly improved survival and haplo-HSCT might be a viable alternative approach.
Allogeneic Hematopoietic Cell Transplantation in First Remission Abrogates Poor Outcomes Associated with High-Risk Pediatric Acute Myeloid Leukemia
