Associations Between Neighborhood-Level Income and Triple-Negative Breast Cancer in a Majority-Minority Population

Does structural racism impact receipt of NCCN guideline-concordant breast cancer treatment?

PURPOSE

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].

CONCLUSION

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.

Racial disparities in disease-specific mortality and surgical management of patients with ductal carcinoma in situ with microinvasion

BACKGROUND AND OBJECTIVES

Given persistent racial disparities in breast cancer outcomes, this study explores racial differences in disease-specific mortality and surgical management among patients with microinvasive ductal carcinoma in situ (DCIS-MI).

METHODS

The Surveillance, Epidemiology, and End Results Program was queried for patients aged 18+ years with DCIS-MI between January 1, 2010 and December 31, 2018. The study cohort was divided into non-Hispanic Black (NHB) and non-Hispanic White (NHW) patients. Disease-specific mortality was evaluated using Cox proportional hazards models.

RESULTS

A total of 3400 patients were identified, of which 569 (16.7%) were NHB and 2831 (83.3%) were NHW. Compared with NHW patients, NHB patients had more positive lymph nodes (7.6% vs. 3.9% p < 0.001). In addition, NHB women were more likely to undergo axillary lymph node dissection (6.0% vs. 3.8%, p = 0.044) and receive chemotherapy (11.8% vs. 7.2%, p < 0.001). There were no racial differences in breast surgery type (p = 0.168), reconstructive surgery (p = 0.362), or radiation therapy (p = 0.342). Overall, NHB patients had worse disease-specific mortality (adjusted hazard ratio 2.13, 95% confidence interval [CI]: 1.10-4.14) with mortality risks diverging from NHW women after 3 years (6 years rate ratio [RR] 2.12, 95% CI: 1.13-4.34; 9 years RR 2.32, 95% CI: 1.24-4.35).

CONCLUSIONS

NHB women with DCIS-MI present with higher nodal disease burden and experience worse disease-specific mortality than NHW women.