Does race predict survival for women with invasive breast cancer?

BACKGROUND

Black women with breast cancer have lower survival rates and higher recurrence rates in comparison with white women. This study compared treatment and survival outcomes for black and white women at a highly specialized tertiary care cancer center.

METHODS

An institutional review board-approved, retrospective institutional database review was performed to identify all black women treated for invasive breast cancer between 2005 and 2010. Women with a prior history of breast cancer, stage IV cancer, or bilateral breast cancer were excluded. White women had similar exclusion criteria applied and were then matched to black women 1:1 by age and diagnosis year. Clinicopathologic and treatment variables were compared by race. Kaplan-Meier methodology was used to estimate overall survival (OS) and disease-free survival (DFS); a multivariable analysis was conducted with Cox regression models.

RESULTS

The study group consisted of 1332 women (666 black). The median tumor size was larger in black women (1.6 vs 1.3 cm; P < .001). Black women had more nodal disease (41.1% vs 32%; P < .001) and had tumors that were more frequently an estrogen receptor-negative (32.9% vs 15%; P < .001), progesterone receptor-negative (47.1% vs 30.2%; P < .001), or triple-negative (TN) subtype (24% vs 8.9%; P < .001) in comparison with white women. Black women also had inferior DFS and OS; race was not an independent prognostic indicator in the multivariable analysis.

CONCLUSIONS

Black women had more advanced disease and adverse prognostic indicators at diagnosis, but race was not an independent predictor of outcome. Black women were significantly more likely to have TN breast cancer. Further research is necessary to understand the differences in tumor biology associated with race.