目的　研究EphA2、上皮间质转化（EMT）在乳腺癌中的表达情况及意义，探讨EphA2与EMT在乳腺癌的侵袭与转移过程中的关系。  方法　采用免疫组织化学方法检测30例乳腺纤维瘤组织和110例乳腺癌中EphA2、E-钙黏蛋白（E-cadherin）、β-连环蛋白（β-catenin）、波形蛋白（vimentin）的表达情况，分析其与乳腺癌临床病理因素的关系及EphA2、E-cadherin蛋白、β-catenin蛋白、vimentin蛋白表达的相关性。   结果　在30例乳腺纤维瘤组织中EphA2、E-cadherin蛋白、β-catenin蛋白、vimentin蛋白阳性率分别为20%、90%、26.67%、13.33%，在110例乳腺癌中的阳性率分别为61.82%、34.54%、64.54% 、68.18%。EphA2的高表达、E-cadherin蛋白的低表达、β-catenin蛋白和vimentin蛋白的高表达与临床分期、淋巴结转移、组织学分级显著相关（P<0.05），EphA2的高表达与E-cadherin蛋白的低表达呈负相关（P<0.05），与β-catenin蛋白、vimentin蛋白的高表达呈正相关（P<0.05）。   结论　EphA2、E-cadherin蛋白、β-catenin蛋白、vimentin蛋白与乳腺癌的侵袭与转移有相关性；EphA2可能通过调控E-cadherin蛋白、β-catenin蛋白、vimentin蛋白的表达来促进EMT，进而在乳腺癌的侵袭和转移过程发挥重要作用。

Objective　To study the expression and significance of EphA2 and epithelial mesenchymal transition (EMT) in breast cancer, and to explore the relationship between EphA2 and EMT in the process of invasion and metastasis of breast cancer.　Methods　The expression of EphA2, E-cadherin protein, β-catenin protein and vimentin protein in 110 cases of breast cancer and 30 cases of breast fibroma tissue were detected by immunohistochemical method. The relationship between EphA2, E-cadherin protein, catenin protein, vimentin protein expression was analyzed.　Results　The positive rates of EphA2, E-cadherin, β-catenin and vimentin were 20%, 90%, 26.67%and 13.33%, respectively, in 30 cases of breast fibroma tissue. The positive rates of EphA2, E-cadherin, β-catenin and vimentin were 61.82%, 34.54%, 64.54% and 68.18%, respectively, in 110 cases of breast cancer. The expression of EphA2, the low expression of E-cadherin protein, the expression of β-catenin protein and vimentin protein were significantly correlated with the clinical stage, lymph node metastasis and histological grade (P<0.05). The expression of EphA2 was lower than that of E-cadherin (P<0.05). There was a positive correlation between the expression of β-catenin and vimentin (P<0.05).　Conclusion　EphA2, E-cadherin protein, β-catenin protein and vimentin proteins are associated with invasion and metastasis of breast cancer. EphA2 may promote EMT by regulating the expression of E-cadherin protein, β-catenin protein and vimentin protein, thus playing an important role in the process of invasion and metastasis of breast cancer.