Mortgage discrimination and breast cancer survival among older women in the United States.

e13615 Background: Although racism and racial residential segregation are widely considered to contribute to health disparities, including in breast cancer, studies examining the impact of mortgage discrimination, a factor contributing to residential racial segregation, and breast cancer survival are limited. The objective of this study is to examine the relationship between redlining (mortgage discrimination based on property location) and survival among older women with breast cancer. Methods: Using the Home Mortgage Disclosure Act (HMDA) database, we estimated redlining for all census tracts in the Metropolitan Statistical Areas (MSAs) within 15 Surveillance Epidemiology and End Results (SEER) areas. This measure was linked by tract with a SEER-Medicare cohort of 27,516 women aged 66-90 years with an incident stage I-IV breast cancer in 2007-2009 and claims information through 2014. We used cox proportional hazards regression models with survival time as the outcome variable and a 4-level categorical logged redlining variable as the key predictor. We also modeled the hazard ratio using redlining as a continuous variable. Models were stratified by stage, ER/PR status, and age group and adjusted for comorbidity and MSA-level standard error. Results: At a median follow-up of 72 months, one-third of the cohort was deceased. The majority of the cohort had no comorbidities and had hormone receptor-positive, early stage (I/II) cancers. Redlining was associated with poorer survival. When redlining is discretized into four groups with approximate equal-sized intervals, the first and second highest redlining groups are significantly associated with all-cause mortality (HR = 1.226 [1.108, 1.355] for the highest group; HR = 1.159 [1.095, 1.228] for the second highest group). When redlining and its quadratic terms are included in the model, the original and square terms are significantly associated with all-cause mortality (HR = 1.177 [1.111, 1.248] for redlining; HR = 0.982 [0.973, 0.991] for squared redlining). Conclusions: The study suggests that redlining could negatively contribute to breast cancer survival. Persistent place-based mortgage discrimination, as a manifestation of institutional racism, could have long-term effects on people’s health, possibly by impacting health care access or exposing residents to harmful neighborhood conditions. Housing policies that seek to reduce or eliminate place-based mortgage discrimination could contribute to reducing breast cancer survival disparities.