Investigation of the miR-637 and miR-523-5p as candidate biomarkers in breast cancer.

Objectives: The distinction of benign lesions from malign tumors is crucial for the diagnosis and treatment of breast cancers.

Background: The aim of this study was to investigate the use of miRNAs as plasma biomarkers for the discrimination of malign and benign breast tumors.

Methods: Whole blood samples obtained from 40 individuals in 3 groups designated as invasive ductal carcinoma group, fibroadenoma group and healthy controls were included in this study. The expression levels of 372 miRNAs were determined using RT-PCR.  Results: The comparison of fibroadenoma group with healthy controls revealed an upregulation of thirty miRNAs and downregulation of twenty-nine miRNAs. The comparison of invasive ductal carcinoma (IDC) group with controls has shown that eight miRNAs were upregulated while eleven miRNAs were downregulated. When comparing IDC and fibroadenoma groups, 15 miRNAs were found to be upregulated, while 10 miRNAs were downregulated. Further analysis of these miRNAs aimed to determine their power in distinguishing  IDCs from fibroadenomas. Among the miRNAs analyzed, seven miRNAs have shown sufficient discriminative power, of which three miRNAs, namely miR-637, miR-523-5p and miR-490-3p, have shown a significantly high discriminative power.

Conclusions: Circulating miR-637 and miR-523-5p combination maybe used to discriminate between invasive ductal carcinomas and fibroadenomas. (Tab. 9, Fig. 4, Ref. 30).