Practical value of identifying circulating tumor cells to evaluate esophageal squamous cell carcinoma staging and treatment efficacy

BackgroundThis study was conducted to investigate the correlation between clinicopathological features and post-therapeutic response in esophageal squamous cell carcinoma (ESCC) patients. Peripheral blood circulating tumor cells (CTCs) expressing epithelial-mesenchymal transition markers were identified. MethodsPeripheral blood samples were collected from 71 patients with newly diagnosed ESCC and 40 healthy volunteers. CTCs were isolated using CanPatrol CTC enrichment technology. RNA-fluorescent in situ hybridization was used to phenotype the CTCs on the basis of epithelial and/or mesenchymal markers. ResultsThe median mesenchymal CTC counts in 71 patients were: 0 in 19 stage I patients, 2 in 31 stage II, and 3 in 21 stage III/IV. The overall diagnostic performance of total CTCs to correctly identify ESCC patients was 0.991. We observed a correlation between increases in tumor size or advanced stage and an increased number of mesenchymal CTCs (P < 0.05). Thirty-nine patients were administered two cycles of neoadjuvant chemotherapy and their therapeutic response was evaluated: 2 complete response, 20 partial response, 13 stable disease, and 4 progressive disease. After treatment, the positive rate of mesenchymal CTCs was 70.6% in the progressive and stable disease group versus 36.4% in the complete and partial response group (P = 0.05). ConclusionThe results showed that mesenchymal CTC count is related to ESCC clinical stage and the efficacy of neoadjuvant chemotherapy.