Objective   To investigate the relationship between the presence of circulating tumor cells (CTCs) and the clinicopathologic characteristics of primary tumor of breast cancer patients.    Methods   Samples of peripheral blood (5 ml) from 128 cases of patients with breast cancer and 30 cases of patients with breast fibroadenoma hospitalized for the first ti

me were enriched by density gradient centrifugation for mononuclear cells

and then the cells were detected by immunofluorescence with anti-cytokeratin8/18 antibody. The relations between the positive rate of CTC and clinicopathologic characteristics of breast cancer patients were analyzed.    Results   The positive rate of CTC in breast cancer patients was 40.6% (52/128)

while CTC was not detected in any patient with breast fibroadenoma. The positive rates of CTC in patients at pathologic lymph node stages (pN

0

pN

1

pN

2

and pN

3

) were 15.4% (6/39)

27.0% (10/37)

64.7% (11/17) and 66.7% (12/18)

respectively. There was significant difference in positive rate of CTC between patients at different pN stages (P=0.000 6). The positive rate of CTC in metastatic breast cancer patients (80.0%

16/20) was significantly higher than that in non-metastatic breast cancer patients (33.3%

36/108) (P=0.000 9). The positive rate of CTC in patients at TNM stage Ⅰ

Ⅱ

Ⅲ and Ⅳ was 12.5% (3/24)

32.0% (16/50)

50.0% (17/34) and 80.0% (16/20)

respectively. There was significant difference in positive rate of CTC between patients at different TNM stages (P=0.000 3).    Conclusion   The presence of CTCs in peripheral blood is correlated positively with lymph mode metastasis

distant metastasis and TNM stage. CTC detection is useful for more accurate risk assessment of patients with breast cancer.