Comparative studies on the expression of tumor-associated glycoprotein (TAG-72), CA 19-9 and DU-PAN-2 in normal, benign and malignant pancreatic tissue.

Expression of tumor-associated glycoprotein (TAG-72) was examined by immunohistochemistry in pancreatic specimens from normal donors, and from patients with chronic pancreatitis and pancreatic cancer, and was compared with expression of CA 19-9 and DU-PAN-2. In the normal pancreas, TAG-72 was expressed in fewer ductal and ductular cells than were CA 19-9 (p less than 0.05) and DU-PAN-2 (p less than 0.01 and 0.001 respectively), whereas in chronic pancreatitis all 3 antigens were expressed in ductal cells but only CA 19-9 and DU-PAN-2 in ductular cells (p less than 0.001). In the specimens from normal pancreas and chronic pancreatitis cases, TAG-72 was localized in the Golgi region, whereas CA 19-9 and DU-PAN-2 showed diffuse cytoplasmic and glycocalyx patterns. In pancreatic cancer, although the rate of expression of all 3 antigens was similar, their cellular localization differed significantly: only TAG-72 was expressed in the Golgi region (p less than 0.001), whereas CA 19-9 showed mainly glycocalyx (p less than 0.05) and/or intra-luminal patterns (p less than 0.01) compared with that of the other 2 antigens. We conclude that, due to differences in expression of TAG-72 in benign versus malignant cells, the monoclonal antibody against TAG-72 (B72.3) may be suitable for radio-immunodetection or radio-immunotherapy of pancreatic cancer.