COMPARISON OF 2 SIALOSYL-TN BINDING MONOCLONAL-ANTIBODIES (MLS102 ANDB72.3) IN DETECTING PANCREATIC-CANCER

An immunohistochemical study has been carried out to compare and contr ast the cellular distribution of two different sialosyl-Tn antigen bin ding monoclonal antibodies, MLS102 and B72.3, in the pancreas. MLS102 but not B72.3 monoclonal antibody binding increases with the content o f the sialosyl-Tn epitopes. It was found that all 13 pancreatic cancer specimens bound both MLS102 and B72.3 monoclonal antibodies. Their ce llular distribution in the cancer was virtually identical. Fifteen of 20 (75%) patients with chronic pancreatitis and five of 10 (50%) norma l subjects were B72.3 positive, but MLS102 was completely negative in the latter group. Both monoclonal antibodies bound fetal pancreas diff usely. Thus, when pancreatic ductal cells have undergone malignant tra nsformation, like the fetal pancreas, they express cell surface and se creted glycoconjugates with increased sialosyl-Tn epitopes suggesting enhanced 2-6 sialosyltransferase activity. This study shows that MLS10 2 is an extremely sensitive and specific tumour marker in the pancreas and that it is better than B72.3 in distinguishing pancreatic cancer from normal and chronic pancreatitis.