OBJECTIVE: Disparities in breast cancer survival remain a challenge. We aimed to analyze the effect of structural racism, as measured by the Index of Concentration at the Extremes (ICE), on receipt of National Cancer Center Network (NCCN) guideline-concordant breast cancer treatment.
METHODS: We identified patients treated at two institutions from 2005 to 2017 with stage I-IV breast cancer. Census tracts served as neighborhood proxies. Using 5-year estimates from the American Community Survey, 5 ICE variables were computed to create 5 models, controlling for economic segregation, non-Hispanic Black (NHB) segregation, NHB/economic segregation, Hispanic segregation, and Hispanic/economic segregation. Multi-level logistic regression models were used to determine the association between individual and neighborhood-level characteristics on receipt of NCCN guideline-concordant breast cancer treatment.
RESULTS: 5173 patients were included: 55.2% were Hispanic, 27.5% were NHW, and 17.3% were NHB. Regardless of economic or residential segregation, a NHB patient was less likely to receive appropriate treatment [(OR)Model1 0.58 (0.45-0.74); ORModel2 0.59 (0.46-0.78); ORModel3 0.62 (0.47-0.81); ORModel4 0.53 (0.40-0.69); ORModel5 0.59(0.46-0.76); p < 0.05].
CONCLUSIONS: To our knowledge, this is the first analysis assessing receipt of NCCN guideline-concordant treatment by ICE, a validated measure for structural racism. While much literature emphasizes neighborhood-level barriers to treatment, our results demonstrate that compared to NHW patients, NHB patients are less likely to receive NCCN guideline-concordant breast cancer treatment, independent of economic or residential segregation. Our study suggests that there are potential unaccounted individual or neighborhood barriers to receipt of appropriate care that go beyond economic or residential segregation.

This paper presents a critique of clinical practice guidelines (CPGs) that standardize the use of race as a proxy for biological difference in medical settings. Drawing on the illustrative example of a pediatric UTI testing guideline, we contend that when CPGs necessitate that Black patients meet a higher threshold of illness severity or duration than their non-Black counterparts to receive comparable medical testing or other medical care, they function as mesolevel sites of race-racism reification processes (see Sewell, 2016) that contribute to the reproduction of racial health disparities. We describe broader implications and make recommendations for the conceptualization and implementation of future research in the sociological study of race, health, and medicine.