Significance of EGFR mRNA Expression in Luminal and Triple Negative Breast Tumors

The epidermal growth factor receptor (EGFR) has critical roles in signal transduction pathways, leading to cell growth and differentiation. EGFR expression levels vary among different breast tumor subtypes and ethnic groups. On the other hand, the relationship between EGFR expression at the mRNA level with clinicopathological characteristics in breast cancer has rarely been reported.
The present study focuses on the assessment of EGFR mRNA expression in breast tumors and the association of its expression with various clinicopathological features in Iranian patients with breast cancer.
In this cross sectional study, the expression of EGFR was assessed by real time PCR technique in tumors of 52 Iranian women (27 luminal and 25 triple negative tumors) with primary breast cancer and 6 normal breast tissues.
The results of this study showed that EGFR mRNA was overexpressed only in triple negative tumors, and there is a high frequency of EGFR underexpression in luminal breast tumors, unlike triple negative tumors. We demonstrated that there is a significant positive correlation (r = 0.662) between EGFR expression and the size of luminal tumors. In the current study, the increased expression of EGFR is significantly associated with estrogen receptor (ER) negative, progesterone receptor (PR) negative, and grade III in breast tumors.
These findings suggest that the majority of patients with triple negative tumors are likely eligible to receive the anti-EGFR therapies. Also, it seems that EGFR expression probably has an association with tumor size in luminal subtype of breast tumors.