Profiles of microRNAs in Patients with Advanced Breast Cancer Who are Chemoresistant or Chemosensitive to Fluorouracil, Adriamycin, and Cyclophosphamide Treatment

OBJECTIVE: Locally advanced breast cancer (LABC) is an inoperable breast adenocarcinoma that is commonly treated with neoadjuvant chemotherapy. Neoadjuvant chemotherapy is given to patients as the first step in treatment to reduce tumor size before surgery. However, no biomarkers are currently available to predict early response to chemotherapy. METHODS: The differential expression of miRNAs between malignant and normal cells from patients with breast cancer reflects tumor dynamics and may reflect an individual's resistance or sensitivity to drugs used in chemotherapy. Ten patients with LABC who responded to chemotherapy, five patients with LABC who did not respond, and three healthy controls were included in this study. RESULTS: This study found that miRNAs miR-214-3p, miR-222-3p, and let-7e-5p indicated a patient's sensitivity to neoadjuvant chemotherapy. Whereas miR-20a-5p, miR-27a-3p, miR-424-5p, miR-152-3p, and miR-195-5p suggested a patient's resistance to it. CONCLUSION: Therefore, these findings suggest that miRNAs may serve as predictive biomarkers and potential therapeutic targets in the management of breast cancer.