Abstract: Objective　To explore the possibility of using circulating cancer cells (CTC) captured by CellCollector® technology for screening breast cancer patients with higher risk of metastasis. Methods　Sixty patients with primary breast cancer were enrolled as the breast cancer group, including 16 in stage Ⅰ, 29 in stage Ⅱ, 11 in stage Ⅲ and 4 in stage Ⅳ. Patients were tested for at least one CTC detection through CellCollector® and followed up for 4-19 months. At the same time, 10 healthy female volunteers were enrolled as the control group, and only one CTC test was performed. The CTC positive rates in patients with different age, menopause, TNM stage, molecular typing and Ki-67 expression were analyzed. Results　The baseline CTC detection rate of breast cancer patients was 73.33%. The detection rates of Ⅰ-Ⅳ stage were 43.75%, 82.76%, 81.82% and 100%, respectively. There were significant differences in the detection rates of CTC under different clinical stages ( P＜0.05). There were no significant differences in CTC detection rates in patients with different age, menopause, molecular typing and Ki-67 expression. Among the 24 patients received twice CTC tests, the number of CTC increased in 1 of the 4 patients with disease progression. Of the 20 progression-free patients, the number of CTC increased in 3 patients, and there was no correlation between the dynamic changes of CTC number and disease progression. Conclusion　The detection rate of CellCollector® in vivo CTC is higher in non metastatic breast cancer. It is possible for CTC to screen patients with breast cancer with higher metastatic risk.

Key words: breast neoplasms, neoplastic cells, circulating, CellCollector?, in vivo detection, dynamic monitoring