BackgroundIt is well known that HOX transcript antisense intergenic ribonucleic acid (HOTAIR) plays an important role in breast cancer (BC). However, whether circulating HOTAIR in plasma could be used for BC diagnosis and dynamic monitoring are unclear. MethodsWe tested the expression levels of HOTAIR in 30 pairs of tissue samples and 148 plasma samples from BC patients by quantitative real time-polymerase chain reaction, and the correlation between plasma HOTAIR levels and clinical features were analyzed. Receiver operating characteristic curve (ROC) was used to assess the diagnostic power of plasma HOTAIR for BC. Furthermore, we explored the monitoring values of plasma HOTAIR for BC and analyzed the correlation of HOTAIR levels between plasma and corresponding tissues of the same patients. ResultsThe expression levels of HOTAIR were significantly higher in BC tissues and plasma than in the control (P< 0.05). The expression levels of plasma HOTAIR were correlated with lymph node metastasis (P=0.018), estrogen receptor (ER) (P=0.012), c-erbB-2 (P=0.006) and triple positive (P=0.015). The area under the ROC curve of plasma HOTAIR was 0.80 (sensitivity 69.2%; specificity 93.3%), which was higher than the carcinoembryonic antigen and carbohydrate antigen 15-3 values obtained. Moreover, plasma HOTAIR expression levels in postoperative patients were lower than those in preoperative patients (P=0.029) and were moderately correlated with the corresponding tissue levels of the same patients (r=0.68, P< 0.0001). ConclusionThese results indicated that HOTAIR may be a potential biomarker for the diagnosis of BC.