Examination of ancestral informative markers and self-reported race with tumor characteristics of breast cancer among black and white women

• Authors: Kerryn W. Reding, Fred Hutchinson Cancer Research Center; Christopher S. Carlson, Fred Hutchinson Cancer Research Center; Orsalem Kahsai, Fred Hutchinson Cancer Research Center; Christina C. Chen, Fred Hutchinson Cancer Research Center; Andrew McDavid, Fred Hutchinson Cancer Research Center; David R. Doody, Fred Hutchinson Cancer Research Center; Chu Chen, Fred Hutchinson Cancer Research Center; India Ornelas, University of Washington; Kimberly Lowe, Exponent; Leslie Bernstein, Beckman Research Institute; Linda Weiss, National Cancer Institute; Jill A. McDonald, Centers for Disease Control and Prevention; Michael S. Simon, Wayne State University; Brian Strom, University of Pennsylvania; Polly A. Marchbanks, Centers for Disease Control and Prevention; Ronald Burkman, Baystate Health; Robert Spirtas, National Institute of Child Health And Human Development, Center for Population Research; Jonathan Liff, Emory University; Kathleen E. Malone, Fred Hutchinson Canc Res Ctr
• Journal Title: Breast Cancer Research and Treatment
• Volume: Volume 134, Number 2
• Publisher: Springer (part of Springer Nature): Springer Open Choice Hybrid Journals | 2012-07-01, Pages 801-809
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1007/s10549-012-2099-0
• Subjects: Health Sciences, Oncology; Health Sciences, Epidemiology
• Keywords: Science & Technology; Life Sciences & Biomedicine; Oncology; Breast cancer; Tumor characteristics; Ancestry informative markers; Self-reported race; AFRICAN-AMERICAN WOMEN; MULTILOCUS GENOTYPE DATA; REPRODUCTIVE EXPERIENCES; ADMIXTURE SCAN; POPULATIONS; INFERENCE; HEALTH; GENES; RISK

Abstract

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 C95 % 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.