Historical Redlining and All-Cause Survival after Breast Cancer Diagnosis

Background: Historical redlining was a 1930s residential segregation policy, in which 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. We hypothesize that worse redlining grade is associated with lower survival. Methods: This New York State Cancer Registry–based cohort included 60,773 breast cancer cases diagnosed between 2008 and 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 HRs 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 with A-grade, residence in B-grade, C-grade, and D-grade neighborhoods 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 stages, 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.