Objective To analyze the relationships of circulating tumor cell (CTC) with prognosis and tumor status of triple-negative breast cancer(TNBC).

Methods CTC was isolated from the peripheral blood of 32 patients confirmed as TNBC and 30 healthy controls, and molecular characteristics were analyzed.

Results Compared with 23 patients with CTC count < 5 in 3.2 mL blood samples, 8 patients with CTC count≥5 had worse progression-free survival and overall survival, and the difference was statistically significant (P=0.033, 0.006), suggesting that the CTC count was valuable in evaluating the prognosis of TNBC patients; among patients with CTC count ≥5 in 3.2 mL blood samples, the presence of CTC clusters was associated with poorer overall survival (P=0.001). Epithelial, mesenchymal, and dry marker gene expression of CTC showed important cellular plasticity, suggesting that the intermediate phenotype of epithelial mesenchymal transformation was associated with effective tumor metastasis, and the molecular characteristics of CTC can effectively predict patients' prognosis.

Conclusion The molecular features of CTC can reveal the tumor status of patients with advanced TNBC and can be used as highly specific biomarkers with the potential for noninvasive prognostic monitoring.