[Pancreatic cancer-associated new carbohydrate antigen]

Antigen T (Thomsen-Friedenreich), a precursor of blood group MN antigens, with the determinant of a carbohydrate (Gal-GalNac), antigen Lewisx (Lex), a trisaccharide found on Type 2 blood group oligosaccharide chains, Sialo-Lex, the derivatives: of Lex and Lewisy (Ley), a difucosylated tetrasaccharide have, behaved as the oncodevelopment tumor-associated antigens in human colon. In the present study, using monoclonal antibodies in immunohistochemical method, the expression and distribution of these antigens in pancreatic cancer and normal pancreatic tissue were observed and compared. It was found that monoclonal antibody AH8-258 derived against antigen T, SSEA-1 and FH-4 derived against short and long chain antigens Lex, FH-6 and IB 9 derived against Sialo-Lex antigen preferentially stained most pancreatic cancer tissues but rarely the normal pancreatic tissues. However, monoclonal antibodies AH-6, KH-1 and CC-1, derived against antigen Ley, stained the majority of tissues regardless of being malignant or normal and were not able to differentiate cancer from the normal tissues. Antigens T, Lex, Sialo-Lex and Ley were also expressed in chronic pancreatitis but the chance of monoclonal antibodies staining in these tissues (18 approximately 36%) was markedly lower than the staining in cancer tissues (54 approximately 77%) except Ley. It is suggested that in human pancreas, haptens T, Lex and Sialo-Lex, the oncodevelopmental cancer-associated antigens, are highly specific markers for malignancy and likely helpful in the early diagnosis of pancreatic cancer.