Clinical significance of EpCAM mRNA-positive circulating tumor cells in hepatocellular carcinoma by an optimized negative enrichment and qRT-PCR-based platform.

Abstract

This study aimed to construct a novel platform for the detection of circulating tumor cells (CTC) in patients with hepatocellular carcinoma (HCC) and to investigate the clinical significance of epithelial cell adhesion molecule mRNA-positive (EpCAM(mRNA+)) CTCs using this platform. An optimized platform for CTC detection was constructed by evaluating different negative enrichment, mRNA isolation, and cDNA synthesis procedures and compared with the CellSearch system. A total of 299 patients with HCC were recruited into this prospective study; of these, 157 who received curative resection, 76 who received transcatheter arterial chemoembolization (TACE), and 66 who received radiotherapy were tested using our platform. The diagnostic value of EpCAM(mRNA+) CTCs was investigated in 122 patients with HCC who underwent resection and 120 control subjects. The optimized negative enrichment and quantitative real-time PCR (qRT-PCR)-based CTC detection platform had high sensitivity, specificity, and reproducibility and a low sample volume requirement. This platform showed a potential diagnostic value in patients with HCC and exhibited 76.7% consistency with the CellSearch system (r = 0.54, P < 0.050). Pretreatment CTC level showed prognostic significance in patients with HCC treated with resection, TACE, and radiotherapy (all P < 0.050). Most of the patients showed a decrease in CTC levels after treatment that reflected tumor response. In contrast, patients with an increased CTC level showed disease progression after treatment. We established an optimized platform based on negative enrichment and qRT-PCR for highly sensitive, specific, and reproducible CTC detection. This platform might be clinically useful in auxiliary diagnosis, treatment response assessment, and early decision-making to tailor the most effective antitumor strategies.