Association of Historical Housing Discrimination and Colon Cancer Treatment and Outcomes in the United States.

Purpose: In the 1930s, the federally sponsored Home Owners' Loan Corporation (HOLC) used racial composition in its assessment of areas worthy of receiving loans. Neighborhoods with large proportions of Black residents were mapped in red (ie, redlining) and flagged as hazardous for mortgage financing. Redlining created a platform for systemic disinvestment in these neighborhoods, leading to barriers in access to resources that persist today. We investigated the association between residing in areas with different HOLC ratings and receipt of quality cancer care and outcomes among individuals diagnosed with colon cancer-a leading cause of cancer deaths amenable to early detection and treatment.
Methods: Individuals who resided in zip code tabulation areas in 196 cities with HOLC rating and were diagnosed with colon cancer from 2007 to 2017 were identified from the National Cancer Database and assigned a HOLC grade (A, best; B, still desirable; C, definitely declining; and D, hazardous and mapped in red). Multivariable logistic regression models investigated association of area-level HOLC grade and late stage at diagnosis and receipt of guideline-concordant care. The product-limit method evaluated differences in time to adjuvant chemotherapy. Multivariable Cox proportional hazard models investigated differences in overall survival (OS).
Results: There were 149,917 patients newly diagnosed with colon cancer with a median age of 68 years. Compared with people living in HOLC A areas, people living in HOLC D areas were more likely to be diagnosed with late-stage disease (adjusted odds ratio, 1.06 [95% CI, 1.00 to 1.12]). In addition, people living in HOLC B, C, and D areas had 8%, 16%, and 24% higher odds of not receiving guideline-concordant care, including lower receipt of surgery, evaluation of ≥12 lymph nodes, and chemotherapy. People residing in HOLC B, C, or D areas also experienced delays in initiation of adjuvant chemotherapy after surgery. People residing in HOLC C (adjusted hazard ratio [aHR], 1.09 [95% CI, 1.05 to 1.13]) and D (aHR, 1.13 [95% CI, 1.09 to 1.18]) areas had worse OS, including 13% and 20% excess risk of death for individuals diagnosed with early- and 6% and 8% for late-stage disease for HOLC C and D, respectively.
Conclusion: Historical housing discrimination is associated with worse contemporary access to colon cancer care and outcomes.