摘要Objective: The aim of this study was to investigate the correlation of STAT3 activation of tumor-associated macrophages (TAMs) and local cytokines (IL-β, TNF-α, TGF-β and IL-12) and prognostic factors in breast cancer. Methods: TAMs in 50 primary breast cancers and macrophages in 15 normal breasts were examined by immunohistochemistry. And STAT3 DNA-binding activity of TAMs in 33/50 primary breast cancers was measured by transcription factor DNA-binding ELISA. In addition, the concentrations of IL-β, TNF-α, TGF-β and IL-12 were measured in the 33 primary breast cancers extracts by ELISA. The correlation between STAT3 activity of TAMs and concentrations of IL-β, TNF-α, TGF-β and IL-12 were analyzed. The correlation between STAT3 activity of TAMs and conventional clinicopathologic parameters were also evaluated. Results: The macrophages density showed a significant increase in primary breast cancers compared to normal breasts. STAT3 DNA-binding activity of TAMs in breast cancer was significantly higher than that of monocytes/macrophages from peripheral blood of the patients. Furthermore, STAT3 activity of TAMs was correlated significantly with the levels of IL-β, TNF-α, TGF-β in breast cancer tissues. But an inverse association was observed between STAT3 activity of TAMs andIL-12. In addition, STAT3 activity of TAMs was higher in high histological type than in low histological type, and STAT3 activity of TAMs was higher in CerBb-2 positive than CerBb-2 negative. Conclusion: STAT3 activation of TAMs may be associate with increasing of IL-β, TNF-αand TGF-β and decreasing of IL-12 in breast cancer. STAT3 activation of TAMs may also be correlated with histological grade and CerBb-2 status of breast cancer.