Genetic polymorphisms in the EGFR (R521K) and estrogen receptor (T594T) genes, EGFR and ErbB-2 protein expression, and breast cancer risk in Tunisia

J Biomed Biotechnol. 2009;2009:753683. doi: 10.1155/2009/753683. Epub 2009 Jul 14.


We evaluated the association of epidermal growth factor receptor (EGFR) 142285G>A (R521K) and estrogen receptor alpha (ESR1) 2014G>A (T594T) single nucleotide polymorphisms with breast cancer risk and prognosis in Tunisian patients. EGFR 142285G>A and ESR1 2014G>A were genotyped in a sample of 148 Tunisian breast cancer patients and 303 controls using PCR-RFLP method. Immunohistochemitsry was used to evaluate the expression levels of EGFR, HER2, ESR1, progesterone receptor and BCL2 in tumors. We found no evidence for an association between EGFR R521K polymorphism and breast cancer risk. However, we found that the homozygous GG (Arg) genotype was more prevalent in patients with lymph node metastasis (P = .03) and high grade tumors (P = .011). The ESR1 2014G allele showed significant association with breast cancer risk (P = .025). The GG genotype was associated with HER2 overexpression and this association withstood univariate and multivariate analyses (P = .009; P = .021, resp.). These data suggest that the R521K might be a prognostic factor, because it correlates with both tumor grade and nodule status. The higher expression of HER2 in ESR1 T594T GG patients suggests the possibility that ESR1 gene polymorphisms accompanied by HER2 expression might influence the pathogenesis of breast cancers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Cohort Studies
  • ErbB Receptors / biosynthesis
  • ErbB Receptors / genetics*
  • ErbB Receptors / metabolism
  • Estrogen Receptor alpha / genetics*
  • Female
  • Genetic Predisposition to Disease
  • Humans
  • Lymphatic Metastasis
  • Middle Aged
  • Multivariate Analysis
  • Polymorphism, Single Nucleotide
  • Receptor, ErbB-2 / biosynthesis*
  • Receptor, ErbB-2 / genetics
  • Tunisia


  • ESR1 protein, human
  • Estrogen Receptor alpha
  • EGFR protein, human
  • ErbB Receptors
  • Receptor, ErbB-2