Abstract A105: Trends in acute lymphocytic leukemia (ALL) incidence in the US from 2000-2016
Authors: Feng Qianxi , Vergara-Lluri Maria , Muskens Ivo , McKean-Cowdin Roberta , Kogan Scott , Brynes Russell , de Smith Adam , Wiemels Joseph 
Published: September 2020

Objectives. The causes of ALL are determined in part by genetic factors but less clear is the role of the environment. Temporal and demographic changes in incidence may help illuminate causes and help direct new lines of research. We sought to investigate in the US from 2000-2016, 1) the distribution of ALL incidence by race/ethnicity, 2) trend change in ALL incidence and 3) the association between ALL incidence and location of birth (US or a foreign country) among different ages and race/ethnicity groups. Methods. We used data from the population-based Surveillance, Epidemiology and End Results (SEER) Registry. Age-adjusted incidence rates (AAIRs) per 100,000 persons were calculated for people of Latino ethnicity (all races), Non-Latino (NL) White, NL Black, NL Asian and Pacific Islander (API), NL American Indian, and Alaskan Native (AIAN). Trends of ALL from 2000 to 2016 were evaluated with the annual percent change (APC) of AAIRs. We further used a Poisson regression model with standardized population offset to analyze the association between the community-level percent of people born in a foreign country and the AAIR of ALL among NL Whites, NL Blacks, and Latinos. The analyses were stratified by race/ethnicity and age groups, and adjusted for sex, year of diagnosis and socioeconomic position (SEP, identified with a time-dependent Yost index variable from census tract). Results. Among 23,829 individuals of all ages diagnosed with ALL from 2000 to 2016 in the US, 8,297 were Latinos, 11,714 were NL Whites, and 1,639 were non-Latino Blacks. Compared to NL Whites (AAIR=1.56), the AAIR was significantly higher for Latinos (AAIR=2.43; p&lt;.001) but lower for NL Blacks (AAIR=0.95; p&lt;.001). The AAIR increased significantly from 2000-2016 overall (APC=0.97; 95% CI:0.67, 1.27), with the highest increase in Latinos (APC=1.18; 95% CI: 0.76, 1.60). The AAIR for NL Whites, APIs, and AIANs remained stable during the study period. In adjusted models, AAIRs increased significantly with the percent of foreign-born for NL Whites (p-trend&lt;.001) and Blacks (p-trend&lt;.001), but decreased with the percent of foreign-born for Latinos (p-trend&lt;.001). This finding was consistent for all age groups. Conclusion. The Age Adjusted Incidence Rates (AAIRs) of ALL from 2000-2016 were highest among Latinos compared to other ethnic groups. Latinos had the fastest increase in AAIR in this period, which was significant in the childhood, young adult, and older adult age groups. Our analysis showed several intriguing trends relating to ethnicity and country of origin which remain unexplained in the scientific literature. Most notably, we show that previously-noted increases in the incidence of ALL for Latinos have continued to climb, in both children and adults, establishing this group as the most highly burdened with this disease. These trends should help direct future research into risk identification and disease prevention in the most vulnerable populations.

Citation Format: Qianxi Feng, Maria Vergara-Lluri, Ivo Muskens, Roberta McKean-Cowdin, Scott Kogan, Russell Brynes, Adam de Smith, Joseph Wiemels. Trends in acute lymphocytic leukemia (ALL) incidence in the US from 2000-2016 [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr A105.