[Expression and significance of Bmi-1 in breast cancer].

Background & Objective: Bmi-1, a putative oncogene, is a member of the polycomb group genes family. It is widely expressed in many kinds of tumors. This study was to investigate the expression and significance of Bmi-1 in breast cancer.

Methods: The expression of Bmi-1 protein in 58 specimens of breast cancer was detected by immunohistochemistry. The correlation of Bmi-1 expression to clinicopathologic features of breast cancer was analyzed.

Results: The intensive positive rate of Bmi-1 in breast cancer was 82.8%. The intensive expression of Bmi-1 was positively correlated to clinical stage and lymph node metastasis (P < 0.05), but not to tumor size, estrogen receptor (ER), progesterone receptor (PR), c-erbB-2 and vascular endothelial growth factor (VEGF) expression (P>0.05).

Conclusions: The intensive expression of Bmi-1 in breast cancer is related to tumor progression. Bmi-1 may serve as a new molecular marker of metastasis of breast cancer.