Racial disparities in treatment and outcomes between Hispanic and non-Hispanic black women with triple-negative breast cancer.

INTRODUCTION

Triple-negative breast cancer (TNBC) is an aggressive breast cancer (BC) subtype with higher incidence and mortality rates in non-Hispanic Black (NHB) women than non-Hispanic Whites. Studies assessing disparities between NHB and Hispanic women, the two largest US racial/ethnic minorities, are lacking. This study evaluates disparities in the treatment and outcomes between NHB and Hispanic women with non-metastatic TNBC.

METHODS

This observational, population-based study using the SEER database included adult, female patients diagnosed with non-metastatic TNBC between 2010 and 2015 and identified as NHB or Hispanic. Logistic regression analysis was used to examine the adjusted odds of receiving breast cancer-directed treatment. Kaplan-Meier and cumulative incidence of death curves were plotted to assess overall survival (OS) and risk of breast cancer-related death, respectively. Multivariate regression analyses with Cox and Fine-Gray methods were calculated to assess factors associated with OS and breast cancer-related death, respectively.

RESULTS

There were 3426 Hispanic and 5419 NHB patients with non-metastatic TNBC. Hispanics had better 5-year OS relative to NHB (76% vs. 72%). No differences in the odds of receiving chemotherapy or surgery between cohorts was seen. However, the odds of undergoing breast-conserving surgery (BCS) and receiving radiation was higher in NHB than Hispanics, (OR, 1.22; 95% CI, 1.10-1.36) and (OR, 1.50; 95% CI, 1.36-1.66), respectively. Lack of radiation therapy was associated with increased BC-related death in NHB relative to Hispanics (sHR, 1.40; 95% CI, 1.19-1.65). Nevertheless, this difference was not seen when radiation was given, (sHR, 1.03; 95% CI, 0.87-1.23).

CONCLUSIONS

We found racial disparities in treatment and outcomes between NHB and Hispanics. NHB were more likely to receive radiation therapy and have BCS. Still, after adjusting for demographic and treatment-related factors, NHB had worse OS and BCSS relative to Hispanics. Additional research is needed to understand the drivers of these disparities.