Multiple mRNA markers for the detection of circulating tumor cells in breast cancer patients

The detection of circulating tumor cells (CTCs) is believed to be a potential method for the early detection of cancer. The aim of this study was to employ a membrane array to develop a panel of mRNA markers for the detection of CTCs in breast cancer patients. Twenty genes with highly differentiated expression levels were selected from microarray studies. The subsequent validation analysis of 30 pairs of breast tissue samples showed that 19 genes demonstrated two-fold overexpression in cancer tissues in comparison with those in normal tissues in 80% of the paired samples. Furthermore, a membrane array experiment was conducted on blood samples from 64 normal controls and 87 breast cancer patients, and the predictive power of each gene was evaluated by analyzing the gene expression level using receiver-operating curves (ROC). Among the 20 genes selected, eight genes that demonstrated the largest areas under the curve (AUC) > 0.8 were selected as diagnostic markers. According to the ROC analysis, when setting the cut-off point of five positive genes, the genetic array of the eight markers was recognized as positive with sensitivity and specificity values of 90% and 89%, respectively. These results suggest that this mRNA marker array could be useful for detecting CTCs in breast cancer patients.