Plasma miR-92a-2 as a biomarker for small cell lung cancer

MicroRNAs (miRNAs) are small, non-coding RNAs that play important roles in the carcinogenesis and progression of cancers. Aberrant expression of miRNAs in tissue and plasma has been found in various solid tumors. Our research aims to determine whether the abnormal plasma miRNA expression patterns can be used as a predictive marker for the diagnosis and prognosis of small cell lung cancer (SCLC). Fifty SCLC patients and 30 healthy controls annotated with clinical characteristics and specific questionnaire survey for smoking history were available. Quantification of several miRNAs (miR-20a-5p, miR-92a-2-5p and miR-17-5p) was performed using quantitative real-time polymerase chain reaction (qRT-PCR), and results were analyzed using SPSS statistics 17.0. Plasma miR-92a-2 level was significantly higher in the SCLC patients group compared with healthy control (P< 0.0001), the receiver operating characteristic (ROC) curve analysis showed that the specificity and sensitivity were at 100% and 56% for diagnosis of SCLC, area under the ROC curve (AUC) was 0.761. No other statistically significant differences were found in the expression level of plasma miR-92a-2 among survival analysis in SCLC. Detection of miR-92a-2 levels in plasma could be a potential and noninvasive method for the diagnosis of SCLC.