Prognostic factors associated with patient characteristics

Age: Several reports have identified older age as an adverse prognostic factor.[11,24,25,27-29] The age effect is not large with regard to OS, but in general, the adverse outcomes seen in adolescents (≥16 years) compared with younger children appear to be primarily caused by increases in toxic mortality.[30] In the COG AAML1031 (NCT01371981) trial, age older than 11 years was an independent predictor of more favorable EFS on multivariable analysis.[31]While outcome for infants with acute lymphoblastic leukemia (ALL) remains inferior to that of older children, outcome for infants (<12 months) with AML is similar to that of older children when they are treated with standard AML regimens.[27,32-34] Infants have been reported to have a 5-year survival rate of 60% to 70%, but with increased treatment-associated toxicity, particularly during induction.[27,32-35]

Race and ethnicity: In both the Children's Cancer Group (CCG) CCG-2891 and COG-2961 (NCT00002798) studies, White children had higher OS rates than Black and Hispanic children.[24,36,37] Black children also experienced lower survival rates than White children in St. Jude Children’s Research Hospital AML clinical trials.[38] Further analysis revealed this disparity was primarily seen in patients who did not harbor core-binding factor variants and received standard induction therapy. This poorer outcome was attributed to a significantly higher prevalence of single nucleotide variants in genes involved in worse cytarabine metabolism in Black children than in White children.[39]

Down syndrome: For children with Down syndrome who develop AML, survival is generally favorable when diagnosed at a young age.[40-42] The prognosis is particularly good (EFS rate exceeding 80%) for children younger than 4 years at diagnosis, the age group that accounts for the vast majority of patients with Down syndrome and AML. Children older than 4 years have similar outcomes to patients without Down syndrome.[42-46]

Body mass index: Obesity (body mass index more than the 95th percentile for age) is predictive of inferior survival.[24,47] Inferior survival was attributable to early treatment-related mortality that was primarily caused by infectious complications.[47,48]