EXPRESSION OF MUCIN CARBOHYDRATES AND CORE PROTEINS IN CARCINOMAS OF THE AMPULLA OF VATER - THEIR RELATIONSHIP TO PROGNOSIS

We examined the expression of carbohydrate antigens which are associat ed with the earliest steps in mucin glycosylation (Tn and sialosyl-Tn) and the expression of the mucin core protein antigens associated with MUC1 gene product (DF3 antigen) as well as MUC2, gene product (intest inal-MRP antigen) in tissues from 38 patients with carcinoma of the am pulla of Vater, in order to determine whether these mucin antigens are available as tumor markers or not, and to evaluate whether their expr ession is correlated with the biological behavior of the carcinomas or not. DF3 antigen showed a relatively high expression rate (61%) in th e carcinoma tissues, but was rarely expressed in the non-neoplastic ep ithelium around the carcinomas in the region of the ampulla of Vater. Tn and sialosyl-Tn antigens showed high expression rates in the carcin oma tissues (86% and 84% each), whereas they showed rare or no express ion in the non-neoplastic epithelium around the carcinomas, except for highly restricted expression in the duodenal villous epithelium. The patients with positive DF3 expression in the carcinoma showed signific antly poorer survival than those with negative DM expression (P<0.05), whereas the patients with positive intestinal-MRP expression in the c arcinoma showed significantly more favorable survival than those with negative intestinal-MRP expression (P<0.05). The expression rate of DF 3 antigen was significantly higher in the cases with deep invasion int o the pancreas (89%) than in those with no or minimal invasion (52%) ( P<0.05). In contrast, the expression rate of intestinal-MRP antigen wa s significantly higher in the cases with no or minimal invasion into t he pancreas (38%) than in those with deep invasion (0%) (P<0.05). In c onclusion, the expression of DF3, Tn and sialosyl-Tn antigens is an ef fective histopathological indicator for carcinomas in the area of the ampulla of Vater, and the expression of DF3 and intestinal-MRP antigen s is a useful indicator of the prognosis of the patients.