Black women at higher risk of triple-negative breast cancer

A new analysis of data from a nationwide hospital-based dataset shows that black women have higher odds of being diagnosed with triple-negative breast cancer-a subtype associated with poorer prognosis-than do white women, regardless of socioeconomic status (SES). The report was published in the June issue of Breast Cancer Research and Treatment.

The goal of the study, by researchers from the American Cancer Society, was to estimate the odds of breast cancer subtypes in minorities versus non-Hispanic whites stratified by SES. The authors used the National Cancer Data Base to identify breast cancer cases diagnosed in 2010 and 2011, the only 2 years since US cancer registries began collecting HER2 results. Breast cancer cases were classified into five subtypes, based on hormone receptor (HR) and HER2 status: HR+/HER2-, HR+/HER2+, HR-/HER2+ (HER2-overexpressing), HR-/HER2- (TN), and unknown.

Odds ratios (ORs) for non-HR+/HER2-subtypes to HR+/HER2- for racial/ethnic groups were estimated using polytomous logistic regression. A composite of insurance status and areal-level incomes were used to control for and stratify by SES.

Non-Hispanic black and Hispanics were 84% (OR=1.84; 95% CI 1.77-1.92) and 17% (OR=1.17; 95% CI 1.11-1.24) more likely than white women to have TN subtypes of breast cancer versus HR+/HER2-, respectively. Odds of being diagnosed with HER2-overexpressing subtype versus HR+/HER2- were 1.45 times greater in Asian/Pacific Islanders than in non-Hispanic white women (OR=1.45; 95% CI 1.31-1.61). The researchers found similar ORs for race in high and low strata of SES. 

To get weekly advice for today's Ob/Gyn, subscribe to the Contemporary Ob/Gyn Special Delivery.