Racial minority patients are impacted differently by the social and physical characteristics of their environments, which may negatively affect cancer outcomes compared with White patients with cancer, according to a new study by Robinson-Oghogho et al presented during the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved (Abstract A115). Addressing these disparities necessitates incorporating processes and tools that tackle structural racism, concluded the study authors.
There is abundant evidence supporting the relationship between societal factors and health outcomes, including those related to cancer. And while some racial disparities in cancer mortality rates in the United States have narrowed, many still persist, leading the Centers for Disease Control and Prevention to declare racism a serious public health threat and contributor to cancer health disparities in 2021.
Study Methodology
The researchers used data for their analysis from a previously developed standard index of county-level structural racism and publicly available data on 2015–2019 cancer mortality rates from the United States Cancer Statistics Data Visualization Tool; 2019 County Health Rankings and Roadmaps; the Environmental Protection Agency’s 2006–2010 Environmental Quality Index report; and 2015–2019 estimates from the Census American Community Survey.
The outcome of interest was the number of deaths for all cancer types per 100,000 people. The researchers’ primary independent variable was the county standardized factor score for structural racism. To account for the counties’ level of environmental burden, they utilized the overall environmental quality index score, and also accounted for factors associated with cancer mortality rates, including race (ie, non-Hispanic Black, White, Asian/Pacific Islander, American Indian/Alaskan Native), adult smoking rates, obesity, excessive drinking, insurance status, rates of sexually transmitted infection, and mammography screening rates, as well as the primary care physician–to-population ratio.
Multiple linear regression analyses were used to examine associations between cancer mortality rates and structural racism standardized factor scores, overall and between racial groups, while accounting for the above covariates, county geographic mobility, and percentage of the population considered to be living in a rural area.
Results
The researchers’ analyses of 1,026 counties in the United States indicated cancer mortality rates increased by 3.3 deaths per 100,000 people (95% confidence interval [CI] = 1.2–5.3) for every standard deviation increase in structural racism factor score, while controlling for all other covariates. Additionally, they found that race modified the relationship between structural racism and cancer mortality. Compared to the White population, cancer mortality rates among Black patients increased by 11.9 deaths per 100,000 individuals (95% CI = 8.8–14.8), Asian/Pacific Islander rates increased by 4.7 deaths per 100,00 individuals (95% CI = 1.3–8.1), and American Indian/Alaskan Native mortality rates increased by 17.4 deaths per 100,000 individuals (95% CI = 4.2–30.6) for every standard deviation increase in county structural racism factor score.
“This demonstrates how race groups are differentially impacted by the social and physical characteristics of their environments. Our analysis extends the evidence illuminating structural racism as a root cause of cancer health disparities,” concluded the study authors.
How Structural Racism Impacts Cancer Outcomes
“Applying measures that attempt to capture the multiple and compounding ways racism presents in policies, laws, and practices at a population level shows how racism manifests beyond interpersonal interactions to negatively impact cancer outcomes,” said presenting study author Joelle N. Robinson-Oghogho, PhD, MPH, a postdoctoral fellow at Johns Hopkins Bloomberg School of Public Health, Department of Health, Behavior, and Society, in a statement. “Studying the impact of structural racism on cancer outcomes allows us to further understand the persistent racial disparities in cancer and broaden our scope of intervention.”
Disclosure: Funding for this study was provided by the National Cancer Institute, the National Institute on Aging, and the National Institute for Minority Health Disparities.
