EXPRESSION OF MUC1 AND MUC2 MUCINS IN GASTRIC CARCINOMAS - ITS RELATIONSHIP WITH THE PROGNOSIS OF THE PATIENTS

Our previous immunohistochemical studies for the expression of MUC1 mu cin antigen (which was detected by monoclonal antibody DF3) and MUC2 m ucin antigen (which was detected by polyclonal antibody anti-MRP) in p ancreatic and intrahepatic bile duct tumors demonstrated that invasive carcinoma with poor outcome showed a pattern of MUC1+ and MUC2- expre ssion, whereas many of the noninvasive tumors with favorable outcome s howed a pattern of MUC1- and MUC2+ expression. To clarify the relation ship between the expression of these mucin antigens and the biological properties of gastric cancers, the expression of MUC1 and MUC2 mucin antigens was examined immunohistochemically in 136 patients with gastr ic cancer invading the submucosa or the deeper layer, and the survival of the antigen-positive and antigen-negative patient groups was compa red using the Kaplan-Meier method. For MUC1 mucin expression, differen t glycoforms of MUC1 were examined using four monoclonal antibodies (N CL-MUC-1-CORE, DF3, MY.1E12, and HMFG-1). The patients with MUC1+ muci n antigen staining in the carcinoma showed significantly worse surviva l than those with MUC1-mucin antigen staining. In contrast, the patien ts with MUC2+ mucin antigen staining in the carcinoma showed significa ntly better survival than those with MUC2- mucin antigen staining. In conclusion, MUC1 antigen expression was associated with a poor outcome in patients with gastric cancer, irrespective of its glycosylation st atus, and MUC1 is thus considered to be a useful prognostic factor for poor outcome in patients. In contrast, MUC2 antigen expression is a p rognostic factor associated with a favorable outcome in patients. In a ddition, combined evaluation of the MUC1 and MUC2 mucin staining is cl inically useful to predict outcome in patients with gastric cancer.