Expression of EGFR mRNA Gene in Peripheral Blood of Breast Cancer Patients and EGFR Protein in Corresponding Tumor Tissues and Its Clinical Significance

Abstract

Objective To evaluate the feasibility of detecting EGFR mRNA by RT-PCR in peripheral blood of patients with breast cancer,to explore the relationship between EGFR mRNA in peripheral blood and EGFR protein in corresponding tumor tissues and to explore its clinical significance.Methods RT-PCR assay was applied to detect the expression of EGFR mRNA in the peripheral blood of 40 patients with breast cancer, 25 patients with benign breast diseases and 30 healthy donors. Expression of EGFR protein in corresponding tumor tissues was detected by immunohistochemistry. Results EGFR mRNA was expressed in 13 of 40(32.5%) patients with breast cancer,compared with both healthy donors (0%)and benign breast disease patients(0%) (P0.01). On the other hand,expression of EGFR protein in corresponding tumor tissues was detected in 25(62.5%) of 40 breast cancer patients by immunohistochemistry. Patients with high expression grade of EGFR protein displayed high expression rate of EGFR mRNA in peripheral blood as well. The expression of EGFR gene was significantly correlated with clinical stage, histological grading and ER, but had no coincidence with pathologic type, tumor size, lymph node metastasis,PR and HER-2.Conclusion Detection of EGFR mRNA in peripheral blood by RT-PCR may be an effective method of detecting CTCs in breast cancers. It may be used as a prognostic indicator and may also contribute significantly to early diagnosis of micrometastasis,the decision on therapies and evaluation of treatment effect.