RESUMO
BACKGROUND: Our aim was to retrospectively analyze the relationships between circulating tumor cells (CTCs) and the development of breast cancer, for elucidating the role of CTCs in breast cancer. METHODS: A total of 107 female patients with primary breast cancer and 48 matched healthy female volunteers were recruited. After blood collection, isolation of peripheral blood mononuclear cells (PBMC) was performed followed by the detection of cytokeratin 19 positive (CK19(+) ) and CD44(+) /CD24(-/low) cells, as well as estrogen receptor (ER), progesterone, and CerbB2. Data were analyzed with the SPSS 20.0 software. RESULTS: None of the 48 volunteers were detected with CK19(+) cells in their PBMC, while in 77 patients, 72% of 107 female patients with primary breast cancer, the CK19(+) cells were detected. CK19(+) could also be detected among patients in each grouping by different clinical staging and lymph node metastasis, with statistical differences (all P < 0.05). Further, among the 83 CK19(+) specimens, 32 were also detected with CD44(+) /CD24(-/low) cells. Comparisons of CK19(+) and CD44(+) /CD24(-/low) cells in patients with different clinical features (ER positive vs. ER negative, C-erbB2 positive vs. C-erbB2 negative) and molecular subtypes (triple-negative breast cancer, ER positive, and C-erbB2 positive) showed no obvious difference (all P > 0.05). CONCLUSIONS: Both CTCs and tumor stem cells (TSCs) could be detected in the PBMC of breast cancer patients; besides, positive expression rate of CTCs might be obviously associated with the clinical stage and metastasis. Positive relationship of TSCs and the clinical stage of breast cancer was also proved in this study.