Background: The aim of this study was to evaluate the prognostic significance of the basal cell-like molecular breast cancer subtype with respect to locoregional recurrence and distant metastasis in African American women treated for breast cancer.
Methods: A retrospective analysis was performed of the tumor registry database for all African American women diagnosed and treated for breast cancer from 1998 to 2005 who had assessable data for all 3 markers: estrogen, progesterone, and Her-2/neu.
Results: A total of 372 patients were included in our study sample. Of these, 22 (6.1%) had locoregional recurrence, 35 (9.8%) had distant metastasis, and 301 (84.1%) had no evidence of breast tumor recurrence. The median follow-up time was 36 months. Compared with the other molecular subtypes the basal cell-like subtype showed a statistically significant association to distant metastasis: 15 (42.9%) vs 13 (37.1%), 4 (11.4%), and 3 (8.6%) (P < .001), respectively, for luminal A, Her-2/neu, and luminal B subtypes. The basal cell-like subtype was an independent predictor of distant metastasis (odds ratio, 5.8; 95% confidence interval, 1.5-22.0, P = .009). The molecular subtypes showed no statistically significant difference with respect to locoregional treatment administered and tumor stage at time of diagnosis.
Conclusions: The basal cell-like molecular breast cancer subtype is an independent predictor of distant metastasis in African American women.