Impact of race and ethnicity on outcomes for estrogen receptor-negative breast cancers: experience of an academic center with a charity hospital

Abstract

Background: African American women have a higher breast cancer mortality rate than Caucasian women. Estrogen receptor (ER)-negative tumors, which are more aggressive than ER-positive tumors, occur more frequently in African American women than in Caucasian women and may contribute to apparent disparities in outcomes. However, outcome results need to be controlled for socioeconomic status (SES). We evaluated the effect of race and ethnicity on outcomes of patients with ER-negative tumors by determining outcomes in African American and Caucasian women with low SES but similar access to care.

Study design: From a prospective database of 786 patients with stage 0 to III breast cancer, all 375 patients with ER-negative tumors were evaluated. Patients received standard definitive operations and adjuvant treatment. Compliance with treatment was more than 90%. Primary endpoints were cancer recurrence and overall survival (OS). Statistical analysis performed included Kaplan-Meier survival analysis, log-rank test, Cox proportional hazard model, Student's t-test, and chi-squared test. A p value < or = 0.05 was considered statistically significant.

Results: Fifty-four percent of African American patients had ER-negative tumors versus 39% in Caucasian patients. In both groups, 69% of patients received free care or Medicaid, with a median income of $16,577 (range $15,367 to $36,788). Comparing the 2 racial and ethnic groups, mean tumor size (p = 0.19), tumor grade distribution (p = 0.32), nodal distribution (p = 0.50), stage distribution (p = 0.30), rate of mastectomy (p = 0.47), receipt of adjuvant chemotherapy (p = 0.07), and financial class distribution (p = 0.67) were not significantly different. The 5-year OS was 77% for both groups (p = 0.59). On multivariate analysis, race and ethnicity were not independent predictors of OS (p = 0.73).

Conclusions: In a predominantly indigent population, race and ethnicity had no impact on outcomes for ER-negative breast cancer.