Black women with breast cancer have worse clinical outcomes even when 21-gene recurrence scores (RS) are similar, according to a study presented at the annual San Antonio Breast Cancer Symposium, held from Dec. 4 to 8 in Texas.
Kathy Albain, M.D., from the Loyola University Chicago Stritch School of Medicine in Maywood, Illinois, and colleagues examined clinicopathologic characteristics, treatment delivered, and clinical outcomes in 9,719 patients from the Trial Assigning Individualized Options for Treatment by race and ethnicity.
The researchers observed no significant difference in the RS distribution or in median or mean RS in blacks versus whites or for Hispanic versus non-Hispanic ethnicity. They also observed no difference in use and type of adjuvant chemotherapy and endocrine therapy or in the duration of endocrine therapy. In the entire population and among patients with an RS of 11 to 25 (intermediate risk for recurrence), black race was associated with worse clinical outcomes (invasive disease-free survival, hazard ratios, 1.33 [P = 0.005] and 1.49 [P = 0.001], respectively; distant relapse-free interval, hazard ratios, 1.21 [P = 0.28] and 1.60 [P = 0.02], respectively; relapse-free interval, hazard ratios, 1.39 [P = 0.02] and 1.80 [P < 0.001], respectively; and overall survival, hazard ratios, 1.52 [P = 0.005] and 1.67 [P = 0.003], respectively). Compared with non-Hispanic ethnicity, Hispanic ethnicity was generally associated with better outcomes.
"Our results suggest that biological differences may contribute to the significantly different outcomes of black women compared to others with breast cancer," Albain said in a statement.
One author disclosed financial ties to the pharmaceutical industry; the genomic test used in the trial was the Oncotype DX Breast Recurrence Score test from Genomic Health.