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Int J Mol Epidemiol Genet 2013;4(4):235-249

Original Article
Epidermal growth factor receptor (EGFR) polymorphisms and breast cancer
among Hispanic and non-Hispanic white women: the Breast Cancer Health
Disparities Study

Avonne E Connor, Richard N Baumgartner, Kathy B Baumgartner, Christina M Pinkston, Esther M John, Gabriela Torres-Mejía,
Lisa M Hines, Anna R Giuliano, Roger K Wolff, Martha L Slattery

Department of Epidemiology & Population Health, School of Public Health and Information Sciences, University of Louisville,
Louisville, KY, USA; Cancer Prevention Institute of California, Fremont, CA; Division of Epidemiology, Department of Health
Research and Policy, and Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA; Instituto
Nacional de Salud Pública, Centro de Investigación en Salud Poblacional, Cuernavaca, Morelos, México; Department of
Biology, University of Colorado Springs, Colorado Springs, CO, USA; H.Lee Moffit Cancer Center & Research Institute, Tampa,
FL, USA; Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA

Received October 24, 2013; Accepted November 8, 2013; Epub November 28, 2013; Published December 15, 2013

Abstract: The epidermal growth factor receptor (EGFR), a member of the ErbB family of receptor tyrosine kinases, functions in
cellular processes essential to the development of cancer. Overexpression of EGFR in primary breast tumors has been linked
with poor prognosis. We investigated the associations between 34 EGFR tagging SNPs and breast cancer risk and breast
cancer-specific mortality in 4,703 Hispanic and 3,030 non-Hispanic white women from the Breast Cancer Health Disparities
Study. We evaluated associations with risk of breast cancer defined by estrogen/progesterone receptor (ER/PR) tumor
phenotype. Only one association remained statistically significant after adjusting for multiple comparisons. Rs2075112GA/AA
was associated with reduced risk for ER-/PR+ tumor phenotype (odds ratio (OR), 0.34; 95% confidence interval (CI) 0.18-0.63,
p adj=0.01). All additional results were significant prior to adjustment for multiple comparisons. Two of the EGFR
polymorphisms were associated with breast cancer risk in the overall study population (rs11770531TT: OR, 0.56, 95% CI 0.37-
0.84; and rs2293348AA: OR, 1.20, 95% CI 1.04-1.38) and two polymorphisms were associated with risk among Hispanics:
rs6954351AA: OR, 2.50, 95% CI 1.32-4.76; and rs845558GA/AA: OR, 1.15, 95% CI 1.01-1.30. With regard to breast cancer-
specific mortality, we found positive associations with rs6978771TT hazard ratio (HR), 1.68; 95% CI 1.11-2.56; rs9642391CC
HR, 1.64; 95% CI 1.04-2.58; rs4947979AG/GG HR, 1.36; 95% CI 1.03-1.79; and rs845552GG HR, 1.62; 95% CI 1.05-2.49. Our
findings provide additional insight for the role of EGFR in breast cancer development and prognosis. Further research is
needed to elucidate EGFR’s contribution to ethnic disparities in breast cancer. (IJMEG1310004).

Keywords: Breast cancer, Hispanic, epidermal growth factor receptor, polymorphisms, tumor phenotype

Address correspondence to: Dr. Avonne E Connor, Department of Epidemiology and Population Health, School of Public
Health and Information Sciences, University of Louisville, 485 E. Gray St. Louisville, KY 40202, USA. Tel: 502-852-6441; Fax:
502-852-3294; E-mail: aeconn02@louisville.edu; Dr. Martha L Slattery, Department of Medicine, University of Utah, 383
Colorow, Salt Lake City, Utah 84108, USA. E-mail: marty.slattery@hsc.utah.edu