Epithelial-to-mesenchymal transition of circulating tumor cells and CD133 expression on predicting prognosis of thyroid cancer patients.

The present study aimed to explore the epithelial-to-mesenchymal transition of circulating tumor cells (CTCs) and CD133 expression in determining the prognosis of patients with thyroid cancer. It enumerated different CTC subtypes and analyzed CD133 gene expression in patients with thyroid cancer to evaluate the relationship between CTC number and thyroid cancer prognosis. In total 394 patients with thyroid cancer were enrolled. Among these, 270 cases had papillary thyroid cancer (PTC), 60 had follicular thyroid cancer (FTC), 30 had medullary thyroid cancer (MTC), 15 had poorly differentiated thyroid cancer, 19 had anaplastic thyroid cancer and 10 had non-malignant thyroid nodules based on their histopathological characteristics. CTC cell counts were determined by CanPatrol CTC capture technique before treatment. The present study also performed reverse transcription-quantitative PCR for CD133 gene expression and evaluated the relationship between CD133 expression and clinical pathology. A total of 330 cases of enrolled patients were classified as differentiated thyroid cancer, which included PTC and FTC. Their prognosis was excellent. The positivity rate of CTCs at diagnosis was 95.5%. The data of the present study showed that early recurrence and metastasis rates in PTC and FTC patients with >6 CTCs and positive mesenchymal circulating tumor cells (MCTCs) were significantly higher than those in patients with <6 CTCs and MCTCs. It was also found that those patients with >6 CTCs and MCTCs had shorter overall survival. In addition, CD133 levels in patients with thyroid cancer were strongly associated with the differentiation grades of thyroid cancers. The detection of >6 CTCs and positive MCTCs in patients with differentiated thyroid cancer was an excellent biomarker for predicting the prognosis of patients. CD133 expression was also identified as a good biomarker for thyroid cancer differentiation.