Do Differences in Treatment Account for Differences in Mortality in Black Women with Triple-Negative Breast Cancer?

A study published in JAMA Oncology compared outcomes between white and Black women with triple-negative breast cancer (TNBC).

“To our knowledge, there is no consensus regarding differences in treatment and mortality between non-Hispanic African American and non-Hispanic White women with TNBC. Little is known about whether racial disparities vary by sociodemographic, clinical, and neighborhood factors,” the study authors explained.

They queried the Surveillance, Epidemiology, and End Results data set to identify 23,123 patients diagnosed with nonmetastatic TNBC between 2010 and 2015 followed up through 2016. Odds ratios (ORs) of treatment receipt and hazard ratios (HRs) of breast cancer mortality were determined with logistic regression analysis and competing risk analysis.

About a quarter of patients were Black (n=5,881 [25.3%]) and the remaining women were white (n=17,332 [74.7%]). In adjusted analyses accounting for sociodemographic, clinicopathologic, and county-level factors, Black women were less likely than white women to receive surgery (OR, 0.69; 95% confidence interval [CI], 0.60-0.79) and chemotherapy (OR, 0.89; 95% CI, 0.81-0.99). A total of 3,276 breast cancer deaths were recorded during 43 months of follow-up. And when adjusting for sociodemographic and county-level factors, the HR for breast cancer mortality for Black women was 1.28 (95% CI, 1.18-1.38); when also adjusting for clinicopathological and treatment factors, the HR was 1.16 (95% CI, 1.06-1.25). The correlation persisted among patients living in socioeconomically less deprived counties (HR, 1.26; 95% CI, 1.14-1.39), urban patients (HR, 1.21; 95% CI, 1.11-1.32), patients having stage II (HR, 1.19; 95% CI, 1.02-1.39) or III (HR, 1.15; 95% CI, 1.01-1.31) tumors that were treated with chemotherapy, and patients younger than 65 years (HR, 1.24; 95% CI, 1.12-1.37), the researchers noted.

“In this retrospective cohort study, African American women with nonmetastatic TNBC had a significantly higher risk of breast cancer mortality compared with their White counterparts, which was partially explained by their disparities in receipt of surgery and chemotherapy,” the researchers wrote in their conclusion.