Serum Levels of Soluble E-Selectin Are Associated With the Clinical Course of Metastatic Disease in Patients With Liver Metastases From Breast Cancer

Abstract

Increasing evidence indicates that the expression of the endothelial adhesion molecule E-selectin is associated with progression and metastasis of breast cancer. Patients with liver metastases also show increased serum levels of the soluble form of E-selectin. It was our aim to compare serum levels of soluble E-selectin (sES) in such patients with the biology of the primary tumor and the course of the metastatic disease under therapy. We examined 69 patients with liver metastases from breast cancer who were selected to receive systemic tumor therapy because of progressive disease (n = 44) or newly detected liver metastases (n = 25). Serum concentrations of sES were measured before each therapy cycle using a specific ELISA. Serum concentrations of sES before the start of therapy were compared to clinical parameters and histopathological findings referring to the primary tumor. Secondly, serum levels of sES were compared to serum concentrations of the corresponding tumor markers. We observed a possible trend for certain unfavorable prognostic parameters (e.g., young women, low-graded tumors, human epidermal growth factor receptor 2 overexpression) to be related to higher serum levels of sES. Serum levels of sES were correlated with tumor marker levels in a logarithmical relation (r = 0.44, P < 0.0005). In some cases it could be demonstrated that serum levels of sES changed similarly to the course of tumor marker levels. We conclude that serum levels of sES are associated with the clinical course of liver metastases from breast cancer. Further investigations are needed to clarify if serum levels of sES may serve as tumor marker in certain clinical situations. E-selectin should be evaluated as a possible target for antimetastatic therapy studies.