Effect of Age on the Prognosis of Molecular Abnormalities in Pediatric Acute Myeloid Leukemia

[Introduction] Infant AML has been defined as AML in patients aged [Methods] This study enrolled patients aged [Results] We first analyzed the distribution of fusion genes and FAB classification in 503 patients with clinical samples. Fusion genes were found in >50% of the patients in each age group. RUNX1-RUNX1T1, KMT2A-R, and CBFB-MYH11 were present in almost all age groups. RUNX1-RUNX1T1 was the most frequently identified fusion gene in all age groups excluding those Furthermore, we analyzed the prognosis of KMT2A-R and CBFB-MYH11 in all 723 patients and confirmed that these fusions had significantly different prognoses between patients In patients with KMT2A-R (n = 131), no molecular markers were identified as prognostic markers in combination with age; however, high WBC counts were related to poor prognosis regardless of age. Particularly, among patients 3-10,000/µL (n = 37) had a significantly poorer prognosis than those with WBC In patients with CBFB-MYH11 with clinical samples (n = 39), NRAS-mutated patients (n = 13) had significantly better 5y EFS and CIR than NRAS-wild-type patients (n = 26) (100% vs 60.5%, p = 0.012, and 0% vs 35.7%, respectively). Moreover, the combination of NRAS status with age identified the worst prognosis in NRAS-wild-type patients [Conclusions] Although age has not been used for the risk stratification of recent pediatric AML clinical trials, it might be a useful prognostic maker of this disease in combination with some molecular makers. Disclosures No relevant conflicts of interest to declare.