Abstract P1-06-01: Associations of historic and contemporary “redlining” with breast cancer stage at diagnosis
Authors: Wiese Daniel , Stroup Antoinette M. , Jemal Ahmedin , Henry Kevin A. , Islami Farhad 
Published: March 2023

Breast cancer is the most commonly diagnosed cancer among US women across all racial/ethnic groups. Stage at diagnosis is one of the major factors determining breast cancer prognosis. The 5-year relative survival for breast cancer ranges from 99% for localized stage at diagnosis, to 84% for regional stage, and to 27% for distant (metastatic) stage breast cancer. The proportion of women diagnosed with breast cancer at later stages (regional and distant) in the US are higher among women with lower socio-economic status and among non-Hispanic Black women. Historic mortgage security redlining, implemented by the Home Owners’ Loan Corporation (HOLC) in the 1930s across numerous US cities, continues to have a negative influence on breast cancer stage at diagnosis, largely due to continued social and economic isolation and poor living environments resulting in many adverse consequences, including lower education, limited job opportunities, no/limited health insurance coverage, and suboptimal access to care, including cancer screening services. Additionally, studies have reported that living in areas with greater contemporary mortgage lending bias towards the non-Hispanic Black population (measured as higher odds of mortgage denial) is associated with late-stage breast cancer diagnosis in several US metropolitan areas.

In this study, we aim to examine the association between the historic HOLC-based “redlining” and contemporary mortgage lending bias and stage of breast cancer at diagnosis among women aged 18 years and older in New Jersey diagnosed with first primary invasive breast cancer in 2010-2015 (N= 32,939). The study population was derived from the New Jersey State Cancer Registry. Historic “redlining” data based on 1930s neighborhood boundaries and transformed to corresponding 2010 census tracts borders were obtained from Inter-university Consortium for Political and Social Research. Mortgage lending bias score for the study period was calculated at the census tract level following methodology developed by Beyers and colleagues. Associations between census tract-level historic “redlining”, contemporary mortgage lending bias and breast cancer stage at diagnosis were evaluated using multinomial logistic regression models after adjusting for age alone, and then for age, race/ethnicity, marital status, and health insurance status.

The study included 21,038 local, 9,765 regional, and 2,136 distant stage breast cancer cases. After adjusting for age, race/ethnicity, marital status, and health insurance, women living in historically redlined census tracts were more likely to be diagnosed with regional (OR=1.23; 95% CI 1.03-1.48) and distant (OR=1.55; 95% CI 1.09-2.22) stage breast cancer compared to women living in other census tracts. Odds for regional (OR=1.14; 95% CI 1.06-1.23) and distant (OR=1.33; 95% CI 1.16-1.53) stage breast cancer were also significantly higher for women living in areas with highest mortgage lending bias score. Stratifying by age (&lt; 65 and &gt;=65 years) showed similar patterns (data not shown).

Both historic “redlining” and contemporary mortgage lending bias were associated with being diagnosed with breast cancer at later stages, notably distant stage. Targeting the legacy of systematic racism and addressing any contemporary discriminatory policies may help reduce breast cancer disparities in the diagnosis stage and thus mortality.

Association between the historic redlining and contemporary mortgage lending bias and stage of breast cancer at diagnosis among women aged ≥18 years in New Jersey, 2010-2015 Note: For contemporary mortgage lending bias, highest score is indicative of highest bias (highest proportion of mortgage denial) towards Black people. *Fully adjusted model includes covariates: age, race/ethnicity, marital status, health insurance status ^Areas designated ”Best” were individual housing markets with sufficient levels of financing and were preserved exclusively for White and wealthy population. Areas defined as “Hazardous” were those lacking financial resources and were designated for Black and poor population.

Citation Format: Daniel Wiese, Antoinette M. Stroup, Ahmedin Jemal, Kevin A. Henry, Farhad Islami. Associations of historic and contemporary “redlining” with breast cancer stage at diagnosis [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-06-01.