Diagnostic Value of Circulating miR-202 in Early-Stage Breast Cancer in South Korea.

: Breast cancer is the most common cancer among women worldwide. Early stage diagnosis is important for predicting increases in treatment success rates and decreases in patient mortality. Recently, circulating biomarkers such as circulating tumor cells, circulating tumor DNA, exosomes, and circulating microRNAs have been examined as blood-based markers for the diagnosis of breast cancer. Although has been studied for its function or expression in breast cancer, its potential diagnostic value in a clinical setting remains elusive and has not been investigated in South Korea. In this study, we aimed to evaluate the diagnostic utility of in plasma samples of breast cancer patients in South Korea. We investigated expression in the plasma of 30 breast cancer patients during diagnosis along with 30 healthy controls in South Korea by quantitative reverse transcription PCR. The results showed that circulating levels were significantly elevated in the breast cancer patients compared with those in healthy controls ( < 0.001). The sensitivity and specificity of circulating were 90.0% and 93.0%, respectively. Additionally, circulating showed high positivity at early stage. The positive rate of was as follows: 100% (10/10) for stage I, 90% (9/10) for stage II, and 80% (8/10) for stage III. was also a predictor of a 9.6-fold high risk for breast cancer ( < 0.001). Additional alternative molecular biomarkers for diagnosis and management of pre-cancer patients are needed. Circulating might be potential diagnostic tool for detecting early stage breast cancer.