Association of cultural racism with breast cancer survival among US adults, 2018-2020.

There are marked racial/ethnic disparities in breast cancer mortality. Cultural racism, expressed through societal norms, stereotypes, and implicit biases, may contribute. We utilized a previously validated state-level multidomain latent measure, the cultural racism factor (CRF). Using data from the Surveillance, Epidemiology, and End Results Program (2018-2020), we evaluated associations between CRF and risk of death using Cox proportional hazards (PH) model with state as random effect. We examined time-varying effects and conducted race- and ethnicity-stratified analyses. Among 225 991 patients, 63% were non-Hispanic (NH) White, 12% were NH Black, and 16% were Hispanic. In the overall cohort, patients in higher CRF states experienced 8% higher risk of death per unit increase in CRF after adjusting for covariates (aHR = 1.08; 95% CI, 1.05-1.11). Time-varying models revealed strongest effects early in follow-up (baseline HR = 1.30; 95% CI, 1.08-1.57), with attenuation over time (interaction HR = 0.99; 95% CI, 0.99-1.00). NH Black women exhibited a pattern suggestive of early elevated mortality risk that attenuated over follow-up (baseline HR = 1.14; 95% CI, 0.96-1.35; interaction HR = 0.99; 95% CI, 0.97-1.00). In conclusion, cultural racism is associated with breast cancer survival at the population level, with the strongest time-dependent effects observed early in follow-up.