Prognostic factors of childhood and adolescent acute myeloid leukemia (AML) survival: evidence from four decades of US population data

Abstract

Growing insight into prognosis of pediatric acute myeloid leukemia (AML) survival has led to improved outcome over time and could be further enhanced through investigation using a large number of patients. To characterize the extent of the association of pediatric AML survival with its identified prognostic factors, we analyzed the United States population-based Surveillance Epidemiology and End Results (SEER) large dataset of 3442 pediatric AML patients diagnosed and followed between 1973 and 2011 using a Cox proportional hazards model stratified by year of diagnosis. Patients diagnosed between 10 and 19 years of age were at a higher risk of death compared to those diagnosed before age 10 (adjusted hazard ratio (aHR): 1.30, 95% confidence interval (CI): 1.17-1.44). African Americans (1.27, 1.09-1.48) and Hispanics (1.15, 1.00-1.32) had an elevated risk of mortality than Caucasians. Compared to the subtype acute promyelocytic leukemia, AML with minimal differentiation (2.44, 1.78-3.35); acute erythroid leukemia (2.34, 1.60-3.40); AML without maturation (1.87, 1.35-2.59); and most other AML subtypes had a higher risk of mortality, whereas AML with inv(16) had a substantially lower risk. Age at diagnosis, race-ethnicity, AML subtype, county level poverty and geographic region appeared as significant prognostic factors of pediatric AML survival in the US. Contrary to previous findings, the subtypes of AML with t(9;11)(p22;q23)MLLT3-MLL, AML without maturation and acute myelomonocytic leukemia emerged to be indicative of poor outcome.

Keywords: Acute myeloid leukemia; Heterogeneous; Prognostic factors; SEER; Stratified Cox-proportional hazard model.

Fig. 1.

Survival of pediatric AML patients by prognostic factors, SEER data, 1973–2011. Survival (unadjusted) by AML subtype was displayed in two plots due to difference in SEER reporting years (Table 1). Subtypes including APL and others (lower left) were available since 1978; data for AML inv(16) and other subtypes (lower right) were available since 2001.