1. ¹Institute of Pathology, Technical University of Munich, Trogerstrasse 18, Munich D-81675, Germany
2. ²Department of Obstetrics and Gynecology, Technical University of Munich, Klinikum rechts der Isar, Ismaningerstrasse 22, Munich D-81675, Germany
3. ³Institute of Medical Statistics and Epidemiology, Technical University of Munich, Ismaningerstrasse 22, Munich D-81675, Germany
4. ⁴Institute of Pathology, GSF-National Research Centre for Environment and Health, Neuherberg D-85764, Germany

Correspondence: Dr K-F Becker, E-mail: kf.becker@lrz.tum.de

⁵Current address: Cancer Research UK Cambridge Research Institute and Department of Oncology, University of Cambridge, Robinson Way, Cambridge, UK.

Received 22 June 2007; Revised 15 October 2007; Accepted 31 October 2007; Published online 20 November 2007.

Abstract

Epithelial ovarian cancer is the leading cause of death among female genital malignancies. Reduced expression of the cell adhesion molecule E-cadherin was previously shown to be associated with adverse prognostic features. The role of the E-cadherin repressor Snail in ovarian cancer progression remains to be elucidated. We analysed formalin-fixed and paraffin-embedded specimens of 48 primary ovarian tumours and corresponding metastases for expression of E-cadherin and Snail by immunohistochemistry. We found a significant correlation between E-cadherin expression in primary cancers and their corresponding metastases (P<0.001). This correlation was found for Snail expression as well (P<0.001). There was a significant (P=0.008) association of reduced E-cadherin expression in primary ovarian cancer with shorter overall survival. Similarly, Snail expression in corresponding metastases (P=0.047) was associated with reduced overall survival of the patients. Additionally, the group of patients showing reduced E-cadherin and increased Snail immunoreactivity in primary tumours and corresponding metastases, respectively, had a significantly higher risk of death (P=0.002 and 0.022, respectively) when compared to the patient group with the reference expression profile E-cadherin positive and Snail negative. Taken together, the results of our study show that the E-cadherin repressor Snail is associated with lower overall survival of ovarian cancer patients.