Historical Redlining Linked to Lower Breast Cancer Screening

Census tracts that received the most severe historical redlining grades had significantly lower breast cancer screening prevalence than the least redlined tracts, even after accounting for present-day social vulnerability, neighborhood conditions, and geographic access to mammography facilities, according to a cohort study published in JAMA Network Open.¹

The study examined 1152 census tracts with historical Home Owners’ Loan Corporation (HOLC) grades across the University of Kansas Cancer Center (KUCC) catchment area, which spans 123 counties in Kansas and Missouri. HOLC grades classify neighborhoods from A ("best") to D ("hazardous") based on perceived mortgage lending risk and have long been used as a marker of historical redlining and subsequent neighborhood disinvestment.

Using census tract-level breast cancer screening prevalence from the CDC's Population Level Analysis and Community Estimates (PLACES) database, which produces small-area health estimates, spanning 2016 to 2024, researchers applied a Bayesian spatiotemporal statistical model designed to account for geographic clustering and year-to-year trends. The model adjusted for Social Vulnerability Index (SVI) quintile, socioeconomic and housing characteristics, transportation access, and distance to the nearest mammography facility.

Grade C, D Tracts Show 6% Lower Screening Odds After Adjustment

Grade C tracts (OR, 0.94; 95% credible interval [CrI], 0.90-0.99) and grade D tracts (OR, 0.94; 95% CrI, 0.89-0.99) had significantly lower adjusted odds of screening compared with grade A tracts. The unadjusted model, by contrast, showed no statistically significant differences between grades.

Median screening prevalence was highest in grade A tracts (79.6%; IQR, 79.0%-80.0%) and lowest in grade D tracts (75.2%; IQR, 71.7%-79.2%), a 4.4 percentage-point gap the authors characterized as a population-level public health signal rather than an individual-level risk estimate.

Poverty, Education Drive Most of the Association

A mediation analysis restricted to 2024 found that the association between HOLC grade D and lower screening operated primarily through socioeconomic pathways. Poverty accounted for the largest share of the total association (44.5%; 95% CI, 22.7%-76.1%), followed by lower educational attainment (25.5%; 95% CI, 6.7%-54.0%); lack of health insurance contributed minimally (1.4%; 95% CI, -11.0% to 15.1%).

In the fully adjusted model, lower educational attainment (OR, 0.94; 95% CrI, 0.92-0.96) and higher mobile home prevalence (OR, 0.98; 95% CrI, 0.97-1.00) were independently associated with lower screening odds. Distance to the nearest mammography facility was not significantly associated with screening after adjustment (OR, 0.97; 95% CrI, 0.93-1.01). The authors noted that some lower-than-expected screening clusters were located near mammography facilities, suggesting proximity alone does not explain the disparity; specific lower-than-expected clusters identified included Independence, Blue Valley, North Kansas City, and Armourdale, while higher-than-expected clusters appeared in Midtown/Hyde Park, Waldo/Armour Hills, and Prairie Village.

Notably, the highest SVI quintile was associated with modestly increased screening odds (OR, 1.08; 95% CrI, 1.01-1.14) in the fully adjusted model. The authors cautioned this finding should be read as a conditional association rather than an overall vulnerability gradient, given SVI's conceptual overlap with the individual socioeconomic and housing covariates modeled separately.

84% of Tract-Years Fell Short of National Screening Target

Substantial residual spatial heterogeneity persisted even after adjustment, with 711 of 1152 tracts (61.7%) showing spatial random effects with 95% credible intervals excluding the null. Screening prevalence also showed strong year-to-year dependence, peaking in 2018 to 2019, remaining stable through 2023, and declining in 2024.

Across the full study period, most tract-years in the catchment area, 972 of 1152 (84.4%), fell short of the Healthy People 2030 breast cancer screening target of 80.3%. Model-based projections for 2025 and 2026 suggested lower-screening patterns may persist in parts of Wyandotte and eastern Jackson counties.

Prior research has similarly linked historical redlining to lower odds of meeting national screening targets for breast, cervical, and colorectal cancer, independent of present-day social vulnerability.²

The authors noted several limitations.¹ The ecological, tract-level design does not permit individual-level inference. CDC PLACES model-based small-area estimates may introduce smoothing and measurement error. HOLC grades were available for only a subset of census tracts, limiting generalizability to nongraded areas; rurality could not be evaluated separately because the analytic sample comprised urban tracts only.

The findings, the authors wrote, support place-based outreach, navigation, and resource allocation strategies targeted at historically redlined neighborhoods and have been shared with KUCC's Community Outreach and Engagement leadership to inform planning.

“Persistent geographic clustering and temporal variation in screening were observed, with scenario-based projections suggesting these disparities may persist despite the passage of time,” wrote the researchers. “These pathway findings should be interpreted as descriptive rather than causal. Together, these findings highlight enduring place-based inequities and support targeted, place-based strategies to advance progress toward national screening targets.”

References

1. Rahman MA, Ratnayake I, Pepper S, et al. Historical redlining and spatiotemporal patterns in breast cancer screening. JAMA Netw Open. 2026;9(9):e2630685. doi:10.1001/jamanetworkopen.2026.30685
2. Moazzam Z, Woldesenbet S, Endo Y, et al. Association of historical redlining and present-day social vulnerability with cancer screening. J Am Coll Surg. 2023;237(3):454-464. doi:10.1097/XCS.0000000000000779