Historical redlining and all-cause survival after breast cancer diagnosis.

Abstract

Background: Historical redlining was a 1930s residential segregation policy, where neighborhoods were graded according to race, class, and land-use. As contemporary neighborhood profiles differ according to historical redlining grade, historical redlining may contribute to current breast cancer disparities. We evaluated whether historical redlining grade is associated with overall 5-year survival in a cohort of breast cancer cases in New York State (NYS). We hypothesize worse redlining grade is associated with lower survival.

Methods: This NYS Cancer Registry-based cohort included 60,773 breast cancer cases diagnosed 2008-2018 and in a census tract at diagnosis with a historical redlining grade. Cases were assigned a grade: A ("best") to D ("hazardous"). Cox models estimated hazard ratios (HR) for 5-year mortality associated with historical redlining grade. We stratified models by case factors and neighborhood characteristics.

Results: Five-year survival displayed a significant gradient with historical redlining (P<0.001). Compared to A-grade, residence in B-grade, C-grade, and D-grade neighborhood was associated with a 29%, 37%, and 64% increase in mortality, respectively (P<0.001). Associations persisted after adjustment for health insurance and treatments. Elevated risk associated with D-grade was specifically observed among non-Hispanic White cases, local and regional stage, hormone receptor-positive tumors, non-triple negative cases, and across neighborhood characteristics. We found significant interaction with redlining grade for race/ethnicity and neighborhood characteristics.

Conclusions: Historical redlining was associated with progressively lower survival for each grade among breast cancer cases. Associations are not fully explained by healthcare factors or contemporary neighborhood characteristics.

Impact: Historical redlining has lasting effects on contemporary breast cancer survival.