ASPO Abstracts
Joint Rural-Urban and Racial/Ethnic Disparities in Early-Onset Colorectal Cancer Incidence and Trends
Category: Cancer Health Disparities
Conference Year: 2020
Abstract Body:
Purpose: To examine joint rural-urban and racial/ethnic trends and disparities in early-onset colorectal
cancer (EOCRC) incidence rates (IR) from 2000 to 2016.Methods: We analyzed data on EOCRC (i.e.,
CRC in persons aged 20-49) incidence from the Surveillance Epidemiology and End Results (SEER),
representing 35% of the U.S. population. We calculated annual percent change (APC) in IR trends
between 2000-2016 jointly by rurality and race/ethnicity (Non-Hispanic White, Non-Hispanic Black, and
Hispanic populations). IRs and rate ratios (RR) were calculated for the most recent 5-year period (2012-
2016). Rural-urban status was determined using the United States Department of Agriculture’s Rural-
Urban Continuum Codes (1-3=urban; 4-9=rural). Results: EOCRC IRs increased 34% among rural
populations between 2000 and 2016 (APC=2.0, p<0.05), compared to a 20% increase among urban
populations (APC=1.3, p<0.05). IRs increased 40.2% between 2000 and 2016 (APC=2.6, p<0.05) in rural
Non-Hispanic White populations compared to a 22.5% increase (APC=1.7, p<0.05) in urban Non-Hispanic
White populations. Among rural Non-Hispanic Black populations, IRs increased 21.4% (APC=0.28,
p>0.05) compared to 10.8% in urban Non-Hispanic Black populations (APC=0.8, p<0.05). EOCRC IRs
increased 20.7% (APC=0.8, p>0.05) in rural Hispanic populations, but 28.1% in urban (APC=1.2, p<0.05).
From 2012 to 2016, the EOCRC IR was 13.8 per 100,000 in rural populations compared to 11.1 in urban
populations (RR=1.25; 95% CI=1.20-1.30). Rural Non-Hispanic White populations had higher rates than
their urban counterparts (RR=1.16, 95% CI=1.13-1.19). Rural Non-Hispanic Black populations also had
higher rates than their urban counterparts (RR=1.16, 95% CI=1.08-1.24) and had the highest IR among all
observed groups (14.8 per 100,000). There was no rural-urban difference among Hispanic populations.
Conclusions: EOCRC IRs increased in both rural and urban populations, but the increase was greater
among rural populations. Rural Non-Hispanic White populations experienced the greatest increase in IR.
Rural Non-Hispanic Black populations had the highest overall IR in the most recent 5-year period. Future
research should examine the etiology of these trends, focusing on geographic and racial/ethnic
disparities.
Keywords: early-onset colorectal cancer; cancer health disparities; surveillance; trends; rural health