Abstract A103: The effect of time on historical redlining disparities in breast cancer survival

Abstract Background: Historical redlining was a 1930s federally-backed residential segregation policy that has been associated with neighborhood profiles today, along with shorter contemporary breast cancer survival. It is unknown whether this disparity has changed over time, as the time since historical redlining increases and advances in screening and treatment have grown. We evaluated whether associations between historical redlining and 5-year survival of breast cancer changed from 1995-2019. Methods: This cohort included 135,827 breast cancer cases from the New York State Cancer Registry that were diagnosed 1995-2019 and resided in a census tract at diagnosis with a historical redlining grade. Cases were assigned a historical redlining grade (range A-D) through linkage to census tracts. Cases were split into five diagnostic time periods: 1995-1999, 2000-2004, 2005-2009, 2010-2014, 2015-2019. Cox proportional hazards models were used to evaluate historical redlining grade and 5-year survival. A multiplicative interaction term between historical redlining grade and diagnostic period was used to test temporal associations and estimate period-specific associations. Interaction models were additionally stratified by stage at diagnosis. Results: Survival probabilities were significantly lower with worse historical redlining grade across all diagnostic periods (all log-rank P≤0.004) but generally showed a narrowing of the disparity over time. We found evidence of time period interaction with historical redlining on survival. Disparities in 5-year survival for D-grade vs. A-grade were largest in 1995-1999 (hazard ratio, HR=1.75, 95% CI: 1.55, 1.98) and lowest in 2005-2009 (HR=1.48, 95% CI: 1.32, 1.66), plateauing through 2010-2014. Significant temporal effects were observed among all stages. The D-grade vs A-grade association was largest in 1995-1999 for local- and regional-stage tumors (HRlocal=1.51, 95% CI: 1.25, 1.82; HRregional=2.26, 95% CI: 1.72, 2.97) and attenuated through time. In contrast, the D-grade vs A-grade association for distant-stage tumors was not statistically significant in 1995-1999 (HR=0.93, 95% CI: 0.74, 1.19) but increased through time to its height in 2010-2014 (HR=1.25, 95% CI: 1.02, 1.53). Conclusion: Associations between historical redlining and breast cancer survival have changed over time, with disparities generally narrowing over time. Stage-stratified results suggest that such disparities may reflect differential access to advances in breast cancer treatment across time. Citation Format: Sarah M. Lima, Tia M. Palermo, Lili Tian, Furrina F. Lee, Tabassum Z. Insaf, Helen CS. Meier, Henry L. Taylor Jr, Deborah O. Erwin, Heather M. Ochs-Balcom. The effect of time on historical redlining disparities in breast cancer survival [abstract]. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr A103.