INCREASED EXPRESSION OF SIALYL LEWIS(X) ANTIGEN IS ASSOCIATED WITH DISTANT METASTASIS IN LUNG-CANCER PATIENTS - IMMUNOHISTOCHEMICAL STUDY ON BRONCHOFIBERSCOPIC BIOPSY SPECIMENS

The tumor-associated carbohydrate antigens sLe(x) and sLe(a) are known to be ligands of endothelial cell leukocyte adhesion molecule-1 (ELAM -1) and to be involved in hematogenous metastasis of human cancer cell s. To determine whether expression of these carbohydrate antigens in l ung cancer is associated with metastatic status, we immunohistochemica lly evaluated the expression of sLe(x) and sLe(a) in 52 bronchofibersc opic biopsy specimens obtained from patients with various stages of pr eviously untreated lung cancer. The incidence of sLe(x) and sLe(a) pos itivity by immunostaining was 65.4 and 13.4%, respectively (P< 0.01). The incidence of sLe(x) positivity in patients with adenocarcinoma (94 .7%) was significantly higher than in patients with squamous cell carc inoma (52.0%) and small cell carcinoma (28.6%) (P < 0.05). The high sL e(x) immunoreactivity correlated with metastasis to a distant organ (P < 0.05), but not with lymph node metastasis. The serum levels of thes e carbohydrate antigens measured by a serological assay correlated wit h their immunohistochemically detected expression (P < 0.01). These fi ndings indicate that sLe(x) is expressed more frequently than sLe(a) i n bronchofiberscopic biopsy specimens and plays an important role in d istant metastasis in lung cancer patients. (C) 1998 Elsevier Science i reland Ltd. All rights reserved.