Serum levels of circulating miRNA-21, miRNA-10b and miRNA-200c in triple-negative breast cancer patients

Introduction: Breast cancer can be classified into five subtypes based on variations in the status of three hormonal receptors that are responsible for the cancer's heterogeneity: estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). These classifications influence the choice of therapies (either neoadjuvant or adjuvant), and the range of prognoses, from good (luminal A subtype) to poor (triple-negative cancers). Objectives: The aim of the study was to compare the serum concentration of selected miRNAs (miRNA-21, miRNA-10b, and miRNA-200c) between in two groups of breast cancer patients with differing ER, PR, and HER2 statuses. Material and methods: The study was performed on two groups of patients. One group (TNBC) consisted of patients with triple-negative cancer, and the other group (ER(+)/PR(+)) was comprised of patients with positive ER and PR receptors. Results: The mean level of miRNA-200c was significantly higher in the ER(+)/PR(+) group than in theTNBC group (p <0.05). No statistically significant difference was found between the two groups with regard to the mean levels of miRNA-21 or miRNA-10b. Conclusions: The level of miRNA-200c was lower in triple-negative patients when compared with the levels in the study's ER/PR positive group.