Expression of Lewis X-related antigens in adenocarcinomas of lung

Abstract

Fifty primary lung adenocarcinomas were examined immunohistochemically using monoclonal antibodies to determine changes in the expression of N‐acetyl‐lactosamine (blood group type‐2 chain), Le^x, Le^Y and sialyl Le^x‐i. These antigens were expressed in 60%, 70%, 90% and 94% of carcinomas, respectively; in 8%, 12%, 56% and 86% of normal broncho‐bronchiolar epithelium; and in 32%, 0%, 100% and 0% of normal alveolar epithelium. The greater the complexity of the antigenic structure, the greater the incidence of positive staining in the adenocarcinomas. Although the more complex antigens such as sialyl Le^x‐i and Le^Y have also been demonstrated in the sera of lung cancer patients, they were not always cancer‐selective in our immunohistochemical study. In contrast, the less complex antigens such as N‐acetyl‐lactosamine (type‐2 chain) and Le^x seem to be cancer‐selective, as they showed low positivity in normal lung tissue.