INCREASED CONCENTRATION OF SOLUBLE E-SELECTIN IN THE SERA OF BREAST-CANCER PATIENTS

E-selectin which is expressed on endothelial cells plays an important role in the adhesion of cancer cells to the vascular endothelium, bein g the ligand for a carbohydrate antigen expressed on cancer cells. In this study, the clinical usefulness of this protein was examined. E-se lectin was expressed on the endothelial cells of the small vessels adj acent to the cancer nests in 63 of the 104 ( 60.6 %) primary tumors of breast cancer. The expression of E-selectin in locations adjacent to the cancer nests was more pronounced than that in distant ones. The me an value of serum soluble E-selectin (ng / mi) was 38.3 in benign brea st disease, 47.8 in those with no evidence of recurrence, 49.4 in stag e I / II primary breast cancer, 75.8 in stage III / IV primary breast cancer; and 93.7 in recurrent breast cancer. The mean value of serum s oluble E-selectin was 106.2 ng / mi in patients with distant metastase s, and 50.4 ng / mi in those with no evidence of distant metastases. T hus, the concentration of soluble E-selectin was significantly elevate d in the sera of patients with distant metastases. These findings sugg ested that cancer cells induced the expression of E-selectin on endoth elial cells and, that serum soluble E-selectin is useful as a tumor ma rker having a close relationship to metastasis in breast cancer.