Disparities in Acute myelogenous leukemia (AML) have been described but not studied extensively in adults. Younger age at diagnosis and cytogenetic profiles of t(8;21) and acute promyelocytic leukemia (APL) subtypes of AML have been associated with improved survival from AML but no studies to date have evaluated these factors by race. The purpose of the current study is to evaluate differences by race/ethnicity in age and select cytogenetic factors at diagnosis. The hypothesis is that disparities for minorities will be explained by older age at diagnosis and lower rates of select favorable cytogenetics.
Patients with AML were identified in the Surveillance Epidemiology End Results (SEER) database during the years 1999–2008. Kaplan-Meier survival curves were generated to predict survival by race/ethnicity, stratified by age. Multivariable Cox proportional hazard models estimated mortality by race with adjustment for age, gender, year of diagnosis, t(8;21) and APL subtypes.
A total of 27,252 patients were included in the study. Blacks and Hispanics were diagnosed at younger ages (<61 years) and had higher rates of t(8;21) and APL compared with non-Hispanic Whites (NHW). The overall KM curve demonstrates that NHWs had a worse survival compared to other races/ethnicities. However when KM curves were stratified by age, blacks and Hispanics had worse survival in every age category below age 61. In multivariable models adjusted for age, black patients had an increased risk of death compared to NHWs (HR 1.10 95% CI (1.04–1.16). In multivariable models adjusted for t(8;21) and APL subtypes, there was no attenuation for the disparity. For APL subtype, in particular, there was an increased disparity for blacks (HR 1.11 95% CI (1.05–1.17) and Hispanics (HR 1.05 95% CI (1.01–1.11) compared to NHWs.
Despite younger age and higher prevalence of favorable cytogenetics, blacks have worse mortality from AML compared to other racial/ethnic groups. Blacks and Hispanics with the APL subtype have worse mortality compared to other racial/ethnic groups. Future studies should investigate other reasons for disparities among black and Hispanics with acute myelogenous leukemia.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.