African-American race is associated with a poorer overall survival rate for breast cancer patients treated with mastectomy and doxorubicin-based chemotherapy.
BACKGROUND
African-American (AA) race has been associated with a worse outcome in breast cancer. It is unclear whether this is due to biological factors, socioeconomic factors, or both.


METHODS
The records from 2 independent cohorts of breast cancer patients treated on institutional protocols with mastectomy and adjuvant (n = 1456) or neoadjuvant (n = 684) doxorubicin-based chemotherapy were retrospectively reviewed.


RESULTS
The adjuvant (Adj) chemotherapy cohort included 1142 Caucasian (CA), 186 Hispanic (HI), and 128 (AA) patients. The neoadjuvant (Neo) chemotherapy protocols included 448 CA, 114 HI, and 122 AA patients. In both groups, AA patients had later-stage tumors (Adj P = .017; Neo P = .051), a higher rate of estrogen receptor (ER)-negative disease (Adj P = .054; Neo P = .039), and a worse 10-year actuarial overall survival rate than CA or HI patients (Adj, 52%, 62%, and 62%, respectively, P = .009; Neo, 40%, 50%, and 56%, respectively, P = .015). In multivariate analyses, AA race remained independently associated with a poorer overall survival rate in both cohorts (Adj, hazard ratio = 1.39, P = .018; Neo, hazard ratio = 1.37, P = .02).


CONCLUSIONS
The data suggest that AA race is associated with less favorable biological tumor features, such as an increased likelihood of ER-negative disease, than those found in CA and HI patients. Such differences in tumor biology, as well as previously described socioeconomic factors, likely contribute to the lower rate of survival in the AA breast cancer population.
Woodward
Wendy A
WA
Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA. wwoodward@mdanderson.org
Huang
Eugene H
EH
McNeese
Marsha D
MD
Perkins
George H
GH
Tucker
Susan L
SL
Strom
Eric A
EA
Middleton
Lavinia
L
Hahn
Karin
K
Hortobagyi
Gabriel N
GN
Buchholz
Thomas A
TA
D000293:Adolescent; D000328:Adult; D001741:Black or African American; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000208:ethnology* / Q000601:surgery / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D002986:Clinical Trials as Topic; D015331:Cohort Studies; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008408:Mastectomy; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D012189:Retrospective Studies; D013629:Tamoxifen / Q000008:administration & dosage
D013629:Tamoxifen; D004317:Doxorubicin