Expression of sialyl-Tn, Tn and T antigens in primary liver cancer.

Sialyl-Tn, Tn and T antigens are caused by aberrant or incomplete glycosylation of apomucins and are related to the aggressiveness of malignant neoplasms. Using 41 liver samples from patients with cholangiocarcinoma (including four with cirrhosis), 21 with combined hepatocellular-cholangiocellular carcinoma and 17 with hepatocellular carcinoma, the expression of sialyl-Tn, Tn and T antigens were characterized immunohistochemically and the correlation with apomucin profiles was evaluated. The prevalence of sialyl-Tn, Tn and T antigens expression was 89, 95 and 51% in cholangiocarcinoma without cirrhosis; 25, 75, and 0% in cholangiocarcinoma with cirrhosis; 29, 90, and 48% in combined hepatocellular-cholangiocellular carcinoma; and 0, 12 and 6% in hepatocellular carcinoma, respectively. Sialyl-Tn antigen was frequently expressed in cholangiocarcinoma without cirrhosis compared with cholangiocarcinoma with cirrhosis and combined hepatocellular-cholangiocellular carcinoma (P < 0.01). Although sialyl-Tn expression was associated with MUC1, MUC6 and MUC7 expression, the expression sites among them were not identical in the individual cases. These data suggest that the different expressions of sialyl-Tn antigen among cholangiocarcinoma without cirrhosis, cholangiocarcinoma with cirrhosis and combined hepatocellular-cholangiocellular carcinoma may reflect the biological features inherent to these tumors, such as the ability of invasion.