- Objective. To investigate the expression of MMP-2, TIMP-1, E-cadherin and β-catenin in endometrial serous carcinoma (ESC), low-grade endometrial endometrioid carcinoma (EEC), and proliferative endometrium. Methods. We performed an immunohistochemical study on 14 cases of ESC, 15 cases of low-grade EEC, and 10 cases of proliferative endometrium. Results. Compared with low-grade EEC, ESC showed significantly increased MMP-2 and TIMP-1 expression, as well as decreased membranous β-catenin staining. E-cadherin expression was significantly lower in ESC and EEC as compared with proliferative endometrium. Conclusions. We suggest that MMP-2 and TIMP-1 expression and loss of β-catenin have a role in the pathogenesis and progression of ESC. Decreased E-cadherin may have an important role in the development of both ESC and EEC. Furthermore, the dissimilarities in MMP-2, TIMP-1, E-cadherin and β-catenin expressions in ESC compared with EEC may be responsible, along with other factors, for their different biological behavior.