Estrogen receptor genes variations and breast cancer risk in Iran

Evidence suggests that alterations in estrogen signaling pathways, including estrogen receptor α (ER-α) and estrogen receptor β (ER-β) occur during breast cancer development. ER-α and ER-β genes polymorphisms have been found to be associated with breast cancer and clinical features of the disease in the western countries. In the current study, we evaluated the hypothesis that certain sequence variants of the ER-α and ER-β genes are associated with an additively increased risk for breast cancer in Iranian women breast cancer patients. The genes were scanned in 150 Iranian patients with newly diagnosed invasive breast tumors and in healthy control individuals by PCR single-strand conformation polymorphism (SSCP) method. Three single nucleotide polymorphisms (SNPs) in codon10 (TCT→TCC), codon 352 (CCG→CCC) and codon 594 (ACG→ACA) in ER-α gene and one SNP codon 392 (CTC→CTG) in ER-β were revealed have additive effects in developing breast cancer and LN metastases. Also, SNP in codon 392 of estrogen receptor-β gene is more effective (threefold) than those SNPs in codons 10, 325, 594 of estrogen receptor-α gene in developing LN metastases in breast cancer patients. SNPs in estrogen receptor α and β have additive effects in increasing risk for developing breast cancer with LN metastases among Iranian women breast cancer patients.