Cancer Epidemiol Biomarkers Prev. 2021 Jun 9:cebp.1728.2020. doi: 10.1158/1055-9965.EPI-20-1728. Online ahead of print.
BACKGROUND: Colorectal cancer (CRC) is curable if diagnosed early and treated properly. Black and Hispanic CRC patients are more likely to experience treatment delays, and/or receive lower standards of care. Socioeconomic deprivation may contribute to these disparities, but this has not been extensively quantified. We studied the interrelationship between patient race/ethnicity and neighborhood socioeconomic status (nSES) on receipt of timely appropriate treatment among CRC patients in California.
METHODS: 26,870 White, Black, and Hispanic patients diagnosed with stage I-III CRC (2009-2013) in the California Cancer Registry were included. Logistic regression models were used to examine the association of race/ethnicity and nSES with three outcomes: undertreatment, >60-day treatment delay, and >90-day treatment delay. Joint effect models and mediation analysis were used to explore the interrelationships between race/ethnicity and nSES.
RESULTS: Hispanics and Blacks were at increased risk for undertreatment (Black OR=1.39, 95%CI=1.23-1.57; Hispanic OR=1.17, 95%CI=1.08-1.27), and treatment delay (Black/60-day OR=1.78, 95%CI=1.57-2.02; Hispanic/60-day OR=1.50, 95%CI=1.38-1.64), compared to Whites. Of the total effect (OR=1.15, 95%CI=1.07-1.24) of non-white race on undertreatment, 45.71% was explained by nSES.
CONCLUSION: Lower nSES patients of any race were at substantially higher risk for undertreatment and treatment delay, and racial/ethnic disparities are reduced or eliminated among non-white patients living in the highest SES neighborhoods. Racial and ethnic disparities persisted after accounting for neighborhood socioeconomic status, and between the two, race/ethnicity explained a larger portion of the total effects.
IMPACT: This research improves our understanding of how socioeconomic deprivation contributes to racial/ethnic disparities in colorectal cancer.