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

Purpose: 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.

Experimental Design: 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.

Results: 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.

Conclusions: 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.