Abstract: Objective To observe retrospectively the protein expression and significance of MMP11 in early breast cancer(EBC),and its relationship with clinical pathological features and the expression conditions of ER,PR and HER2.Methods A total of 76 cases with EBC were followed up in this study.The protein expressions of MMP11,ER,PR and HER2 in tumors were detected by immunohistochemical staining and statistical analysis.Results The positive expression rate of MMP11 protein was 68.42%.The expression of MMP11 was not related to the features such as histopathological type,PR expression,age and prognosis of the patients(P>0.05),but positive related to menopausal status of patient and ER expression of tumor(P<0.05).Univariate analysis showed the expressions of MMP11,ER and HER2 were correlated with prognosis,but multivariate analysis showed none of these protein expression related to prognosis.Conclusions The results of this small pilot study suggest that the expression of MMP11 protein in EBC was correlated with menopausal status and ER expression,but not correlated with prognosis.The role of MMP11 in EBC requires further study.

Key words: MMP11, Early breast cancer(EBC), Prognosis