African American (AA) women have a higher mortality from breast cancer (BC) compared to European American (EA) women. This may be due to the higher proportion of AA women with tumors that are diagnosed at more advanced stages and are characterized as being estrogen receptor negative (ER−)/progesterone receptor negative (PR−). Our study sought to determine whether self-reported race and percent African ancestry were associated with BC tumor characteristics. In a multi-center, population-based case–control study of BC, we determined percent African ancestry using ancestry informative markers (AIM) among women self-reporting race as AA or Black. BC tumor characteristics were associated with self-reported race (including a 30 % reduction in ER+/PR+ tumors [95 % confidence interval [CI]: 0.6–0.9] and a 1.5-fold increased risk of high grade [95 % CI: 1.2–1.9] for AA women compared to EA women). AIMs among AA women were not associated with BC tumor characteristics (AA women with ≥95 % versus <80 % African ancestry, odds ratio [OR] = 1.0 for ER+/PR+ [95 % CI: 0.6–1.8] and OR = 0.9 for high-grade tumors [95 % CI: 0.6–1.4]). Similar findings were observed for BC stage. While BC subtypes were associated with self-reported race, BC subtypes were not associated with percent African ancestry. These study results suggest that subtle differences in percent African ancestry are less important than the overall presence of African ancestry in relation to BC tumor characteristics.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Price excludes VAT (USA)
Tax calculation will be finalised during checkout.
Siegel R, Naishadham D, Jemal A (2012) Cancer statistics, 2012. CA Cancer J Clin 62(1):10–29
Ademuyiwa FO et al (2011) Breast cancer racial disparities: unanswered questions. Cancer Res 71(3):640–644
Morris GJ, Mitchell EP (2008) Higher incidence of aggressive breast cancers in African-American women: a review. J Natl Med Assoc 100(6):698–702
Li CI, Malone KE, Daling JR (2002) Differences in breast cancer hormone receptor status and histology by race and ethnicity among women 50 years of age and older. Cancer Epidemiol Biomarkers Prev 11(7):601–607
Simon MS et al (2006) Breast cancer risk estimates for relatives of white and African American women with breast cancer in the Women’s Contraceptive and Reproductive Experiences Study. J Clin Oncol 24(16):2498–2504
Huo D et al (2009) Population differences in breast cancer: survey in indigenous African women reveals over-representation of triple-negative breast cancer. J Clin Oncol 27(27):4515–4521
Lund MJ et al (2008) Parity and disparity in first course treatment of invasive breast cancer. Breast Cancer Res Treat 109(3):545–557
Fedewa SA et al (2010) Delays in adjuvant chemotherapy treatment among patients with breast cancer are more likely in African American and Hispanic populations: a national cohort study 2004-2006. J Clin Oncol 28(27):4135–4141
Dignam JJ (2000) Differences in breast cancer prognosis among African-American and Caucasian women. CA Cancer J Clin 50(1):50–64
Ooi SL, Martinez ME, Li CI (2011) Disparities in breast cancer characteristics and outcomes by race/ethnicity. Breast Cancer Res Treat 127(3):729–738
Taylor TR et al (2007) Racial discrimination and breast cancer incidence in US Black women: the Black Women’s Health Study. Am J Epidemiol 166(1):46–54
Gerend MA, Pai M (2008) Social determinants of Black-White disparities in breast cancer mortality: a review. Cancer Epidemiol Biomarkers Prev 17(11):2913–2923
Fejerman L et al (2009) An admixture scan in 1,484 African American women with breast cancer. Cancer Epidemiol Biomarkers Prev 18(11):3110–3117
Marchbanks PA et al (2002) The NICHD Women’s Contraceptive and Reproductive Experiences Study: methods and operational results. Ann Epidemiol 12(4):213–221
Rothman KJ (1986) Modern epidemiology, 1st edn. Little Brown, Boston.
Greenland S, Thomas DC (1982) On the need for the rare disease assumption in case-control studies. Am J Epidemiol 116(3):547–553
Malone KE et al (2006) Prevalence and predictors of BRCA1 and BRCA2 mutations in a population-based study of breast cancer in white and black American women ages 35 to 64 years. Cancer Res 66(16):8297–8308
Kosoy R et al (2009) Ancestry informative marker sets for determining continental origin and admixture proportions in common populations in America. Hum Mutat 30(1):69–78
Pritchard JK, Stephens M, Donnelly P (2000) Inference of population structure using multilocus genotype data. Genetics 155(2):945–959
Falush D, Stephens M, Pritchard JK (2003) Inference of population structure using multilocus genotype data: linked loci and correlated allele frequencies. Genetics 164(4):1567–1587
Reding KW et al (2012) Estrogen-related genes and their contribution to racial differences in breast cancer risk. Cancer Causes Control 23(5):671–681
Patterson N et al (2004) Methods for high-density admixture mapping of disease genes. Am J Hum Genet 74(5):979–1000
Ruiz-Narvaez EA et al (2011) Validation of a small set of ancestral informative markers for control of population admixture in African Americans. Am J Epidemiol 173(5):587–592
Reich D et al (2005) A whole-genome admixture scan finds a candidate locus for multiple sclerosis susceptibility. Nat Genet 37(10):1113–1118
Smith MW et al (2004) A high-density admixture map for disease gene discovery in African Americans. Am J Epidemiol 74(5):1001–1013
McGregor BA, Antoni MH (2009) Psychological intervention and health outcomes among women treated for breast cancer: a review of stress pathways and biological mediators. Brain Behav Immun 23(2):159–166
McClintock MK et al. (2005) Mammary cancer and social interactions: identifying multiple environments that regulate gene expression throughout the life span. J Gerontol B Psychol Sci Soc Sci 60(1):32–41
The authors would like to thank the study participants for their contribution to this research. The Women’s CARE study was supported by the National Institute of Child Health and Human Development, with additional support from the National Cancer Institute, through contracts with Emory University (N01 HD 3-3168), the Fred Hutchinson Cancer Research Center (N01 HD 2-3166), Karmanos Cancer Institute at Wayne State University (N01 HD 3-3174), the University of Pennsylvania (N01 HD-3-3176), and the University of Southern California (N01 HD 3-3175) and through an intra-agency agreement with the Centers for Disease Control and Prevention (Y01 HD 7022). The research generating the AIMs data was supported by the National Cancer Institute (R03 CA 123584). KWR was supported by the Cancer Epidemiology and Biostatistics Training Grant (2 T32 CA 09168) and NINR career development grant (K99 NR 012232). The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the National Institutes of Health and the Centers for Disease Control and Prevention.
About this article
Cite this article
Reding, K.W., Carlson, C.S., Kahsai, O. et al. Examination of ancestral informative markers and self-reported race with tumor characteristics of breast cancer among black and white women. Breast Cancer Res Treat 134, 801–809 (2012). https://doi.org/10.1007/s10549-012-2099-0