Abstract: BACKGROUND＆AIM: To study the correlation between the expression of extracellular matrix metalloproteinase inducer(EMMPRIN)and matrix metalloproteinase_9(MMP_9) and the development and metastasis of breast carcinoma. MATERIALS AND METHODS: The expressions of EMMPRIN and MMP_9 were evaluated by immunohistochemical staining in 21 cases of breast hyperplasia, 10 cases of intraductal carcinoma and 68 cases of invasive breast ductal carcinoma. RESULTS: ①The positive rates of EMMPRIN expression in hyperplasia, intraductal carcinoma and invasive breast carcinoma were 4.76％ (1/21), 40.00％ (4/10) and 73.53％ (50/68), respectively. Significant difference was found among three groups (P<0.05); ②The positive rates of MMP_9 expression in hyperplasia, intraductal carcinoma and invasive breast carcinoma were 0.00％ (0/21), 30.00％ (3/10) and 69.12％ (47/68), respectively. Significant difference was found among three groups too (P<0.05); ③ The expression of EMMRIN significantly correlated with the expression of MMP_9 in breast ductal carcinoma (rs=0.676,P<0.01). Axillary lymph node metastasis and the number of metastatic node were related to the expression of EMMPRIN and MMP_9 in breast ductal carcinoma(P<0.05). CONCLUSION: The over_expression of EMMPRIN and MMP_9 may play important roles in the development of breast carcinoma.They were found to be important factors that promoted the invasion and metastasis of breast carcinoma.EMMPRIN and MMP_9 could be important markers for evaluating invasion and metastasis of breast carcinoma.

Key words: breast carcinoma, metastasis, extracellular matrix metalloproteinase inducer (EMMPRIN), matrix metalloproteinase_9 (MMP_9), immunohistochemistry