Soluble serum E-cadherin as a marker of tumour progression in colorectal cancer patients.

A pilot study was conducted to determine the concentrations of soluble serum E-cadherin in 36 patients with colorectal cancer or a high-grade dysplasia by the use of an ELISA technique. The results were compared with staging characteristics and concentrations of routine serum carcinoembryonic antigen (CEA). Sixteen patients with benign diseases and nine healthy volunteers served as internal or negative controls. Tumour specimens from seven patients were analysed by immunohistochemistry to compare concentrations of soluble serum E-cadherin with patterns of cell-bound E-cadherin or beta-catenin. Serum E-cadherin concentrations were increased in colorectal cancer patients (P = 0.009), but also in benign disease controls (P = 0.005), correlating with the T- (P < 0.05), but not N- or M-stage, and with serum CEA (P = 0.002) in case of existing liver metastases. Compared with other staining patterns, concentrations of soluble serum E-cadherin were higher in case of an exclusive membrane-bound localization of cellular beta-catenin (P = 0.071). The results suggest marker characteristics of soluble serum E-cadherin in colorectal cancer patients, but lacking specificity argues against a routine clinical use.