Racial and Ethnic Differences in Socioeconomic Position and Risk of Childhood Acute Lymphoblastic Leukemia

Racial and ethnic differences in associations between socioeconomic position (SEP) and risk of childhood acute lymphoblastic leukemia (ALL) were investigated using data from population-based cancer registries in the Surveillance, Epidemiology, and End Results Program in the United States. The study included 8,383 ALL cases diagnosed at age <= 19 years in 2000-2010. Census tract-level composite SEP index in quintiles was assigned based on residence at the time of diagnosis. Incidence rate ratios and 95% confidence intervals associated with SEP and race/ethnicity, adjusted for sex, age, and year of diagnosis, were estimated using Poisson regression models. The incidence rate of childhood ALL was negatively associated with SEP among Hispanics but was positively associated among children of other races/ethnicities. As compared with the lowest SEP, the adjusted incidence rate ratios for children with the highest SEP were 1.29 (95% confidence interval (CI): 1.15, 1.44) for non-Hispanic whites, 1.67 (95% CI: 1.20, 2.34) for non-Hispanic blacks, 1.57 (95% CI: 1.17, 2.09) for Asians/Pacific Islanders, 2.33 (95% CI: 0.93, 5.83) for American Indians/Alaska Natives, and 0.70 (95% CI: 0.60, 0.81) for Hispanics. The findings of a reverse association in Hispanics need to be confirmed and further explained in future studies using different measures of SEP.