Detection of circulating tumor cells in peripheral blood from patients with gastric cancer using piRNAs as markers

Objective: To investigate the feasibility of detecting circulating cancer cells in peripheral blood from gastric cancer patients using Piwi-interacting RNAs (piRNAs) as markers. Design and methods: Real-time quantitative reverse transcription-polymerase chain reaction was used to analyze piR-651 and piR-823 levels in the peripheral blood of 93 patients with gastric cancer and 32 healthy volunteers. Receiver operating characteristic (ROC) curves were constructed to evaluate the diagnostic values. Results: The peripheral blood levels of piR-651 and piR-823 in the patients with gastric cancer were significantly lower than those from controls (P<0.001). The piR-651 level in gastric adenocarcinoma was higher than that in gastric signet ring cell carcinoma (P=0.003). The piR-823 level was positively associated with tumor-node-metastasis stage (P=0.027) and distant metastasis (P=0.026). The areas under the ROC curve were 0.841, 0.812 and 0.860 for piR-651, piR-823 and the combination, respectively. Conclusions: piRNAs may be valuable biomarkers for detecting circulating gastric cancer cells. (C) 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.