ICAM-1 expression and the soluble ICAM-1 level for evaluating the metastatic potential of gastric cancer.

ICAM-1 plays an important role in cell-cell and cell-extracellular matrix interactions, especially tumor invasion and cytotoxicity of lymphocytes. In the present study, the relationship between metastasis of gastric cancer and ICAM-1 expression by cancer cells or the serum level of s-ICAM-1 was (s-ICAM-1) was examined. ICAM-1 was detected by immunohistochemic staining in 49.0% of 108 patients with gastric cancer. The ICAM-1 expression rate was higher at a more advanced stage, based on lymph node metastasis, being 46.9% in node-negative and 56.1% in node-positive cases. In patients with liver metastasis, the rate was 90.9%, while it was 43.3% in patients without liver metastasis (p < 0.05). The serum s-ICAM-1 level was 262.1 ng/ml (median 205.5, range 176.0-271.0) in healthy subjects and 391.5 ng/ml (median 317.5, range 148.7-1,768.0) in gastric cancer patients (p < 0.001). The serum s-ICAM-1 level was significantly higher in patients with liver metastasis than in patients without liver metastasis (p < 0.0001). In addition, positive ICAM-1 expression cases had significantly higher s-ICAM-1 levels than negative ones, 408.9 +/- 188.4 and 308.1 +/- 88.1 ng/ml, respectively. These results suggested that ICAM-1 was overexpressed in cancer cells and released as s-ICAM-1, which would promote hematogenous metastasis by suppressing local anticancer immunity. Copyright 2002 Wiley-Liss, Inc.