ABSTRACT: BACKGROUND:MicroRNAs (miRNAs) play an important role in the development and progression of breast cancer (BC). The purpose of the present study was to identify plasma miRNAs enabling early diagnosis of BC. MATERIALS AND METHODS:Expression levels of seven plasma miRNAs (miR-23a-3p, miR-29b-2-5p, miR-130a-5p, miR-144-3p, miR-148a-3p, miR-152-3p, and miR-182-5p) in 106 patients with newly diagnosed BC and 96 healthy participants were analyzed by qRT-PCR. We also evaluated the relationship between the expression levels of these miRNAs and clinicopathological features of patients with BC. RESULTS:Compared with healthy controls, we found that miR-23a-3p (p = .025), miR-130a-5p (p = .006), miR-144-3p (p = .040), miR-148a-3p (p = .023), and miR-152-3p (p = .019) were downregulated in the plasma of patients with BC. MiR-130a-5p, miR-144-3p, and miR-152-3p were downexpressed in BC tissues as well as plasma. The expression of the miR-23a-3p, miR-144-3p, and miR-152-3p was related to ER positive and PR positive. Besides, miR-23a-3p, miR-144-3p, and miR-152-3p did show the significant difference in the staging compromised to the control, especially in stage I-II. Moreover, we also found that miR-144-3p and miR-148a-3p were associated with lymph node invasion. CONCLUSIONS:The expression levels of the miR-23a-3p, miR-130a-5p, miR-144-3p, miR-148a-3p, and miR-152-3p were lower in patients with BC compared to healthy controls and were associated with ex hormone receptor, clinical stage, and lymph node metastasis, indicating the diagnostic potential of these miRNAs in BC.