Long noncoding RNAs (lncRNAs) have been gradually confirmed to be tumor-associated biological molecules and became interesting new diagnostic targets of cancer. However, the clinical significances of most cancer-related lncRNAs are largely unknown. Here, we evaluated, for the first time, the feasibility and clinical significances of circulating serum lncRNA RP11-445H22.4 as biomarker for the detection of breast cancer (BC). In this study, the relative concentrations of breast cancer-associated lncRNA RP11-445H22.4 were investigated in a total of 136 serum samples by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). The correlations between the levels of serum lncRNA RP11-445H22.4 in breast cancer patients and the clinicopathological factors of these patients were further analyzed. Receiver operating characteristic (ROC) curve was constructed to evaluate the diagnostic values. In breast cancer patients, the expression level of lncRNA RP11-445H22.4 is significantly increased (p < 0.001). The sensitivity and specificity of RP11-445H22.4 for BC were 92 and 74 %, respectively. Its expression levels were correlated with estrogen receptor (ER), progesterone receptor (PR), and menopausal status of the breast cancer patients (p < 0.05). For the detection of breast cancer, the use of RP11-445H22.4 showed a remarkable improvement compared with the clinical serum carcinoembryonic antigen. In conclusions, lncRNA RP11-445H22.4 may be a new potential biomarker of breast cancer.
Keywords: Breast cancer; Serum biomarker; lncRNA RP11-445H22.4.