Abstract
Purpose: Population-based incidence rates of breast cancers that are negative for estrogen receptor (ER), progesterone receptor, and human epidermal growth factor receptor 2/ neu (triple-negative breast cancer [TNBC]) are higher among African American (AA) compared with white American (WA) women, and TNBC prevalence is elevated among selected populations of African patients. The extent to which TNBC risk is related to East African versus West African ancestry, and whether these associations extend to expression of other biomarkers, is uncertain.
Methods: We used immunohistochemistry to evaluate estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2/ neu, androgen receptor and aldehyde dehydrogenase 1 (ALDH1) expression among WA (n = 153), AA (n = 76), Ethiopian (Eth)/East African (n = 90), and Ghanaian (Gh)/West African (n = 286) patients with breast cancer through an institutional review board-approved international research program.
Results: Mean age at diagnosis was 43, 49, 60, and 57 years for the Eth, Gh, AA, and WA patients, respectively. TNBC frequency was higher for AA and Gh patients (41% and 54%, respectively) compared with WA and Eth patients (23% and 15%, respectively; P < .001) Frequency of ALDH1 positivity was higher for AA and Gh patients (32% and 36%, respectively) compared with WA and Eth patients (23% and 17%, respectively; P = .007). Significant differences were observed for distribution of androgen receptor positivity: 71%, 55%, 42%, and 50% for the WA, AA, Gh, and Eth patients, respectively ( P = .008).
Conclusion: Extent of African ancestry seems to be associated with particular breast cancer phenotypes. West African ancestry correlates with increased risk of TNBC and breast cancers that are positive for ALDH1.
Conflict of interest statement
Evelyn Jiagge
No relationship to disclose
Aisha Souleiman Jibril
No relationship to disclose
Melissa Davis
Employment: Henry Ford Health System
Carlos Murga-Zamalloa
No relationship to disclose
Celina G. Kleer
No relationship to disclose
Kofi Gyan
No relationship to disclose
George Divine
Employment: Henry Ford Hospital
Mark Hoenerhoff
No relationship to disclose
Jessica Bensenhaver
No relationship to disclose
Baffour Awuah
No relationship to disclose
Joseph Oppong
No relationship to disclose
Ernest Adjei
No relationship to disclose
Barbara Salem
No relationship to disclose
Kathy Toy
No relationship to disclose
Sofia Merajver
No relationship to disclose
Max Wicha
Consulting or Advisory Role: MedImmune
Research Funding: MedImmune
Patents, Royalties, Other Intellectual Property: Stockholder in OncoMed Pharmaceuticals
Lisa Newman
No relationship to disclose