Immunohistochemical studies on the localization of cancer associated antigens DU‐PAN‐2 and CA19‐9 in carcinomas of the digestive tract

Abstract

The immunohistochemical localization of DU‐PAN‐2 antigen and CA19‐9 antigen in carcinomas of the digestive tract was studied using an immunoperoxidase technique. Staining for DU‐PAN‐2 antigen and CA19‐9 antigen was observed in 104 (79%) and 96 (73%) of 131 carcinomas of the digestive tract, respectively. Diffuse staining (more than 20% of carcinoma cell stained) for DU‐PAN‐2 was detected in 14 of 21 (67%) pancreatic carcinomas and 11 of 19 (58%) carcinomas of the biliary tract (including cholangiocarcinoma). Diffuse staining for CA19‐9 was detected in 15 (71%) of pancreatic carcinomas and nine (47%) of the carcinomas of the biliary tract. In colon carcinomas, no diffuse staining for DU‐PAN‐2 was observed, whereas diffuse staining for CA19‐9 was found in 41%. There was a positive correlation between the differentiation degree (or grade) of the adenocarcinomas of the colon and the expression of CA19‐9, but not that of DU‐PAN‐2. These immunohistochemical studies showed that DU‐PAN‐2 antigen is expressed diffusely in most cases of adenocarcinoma of the pancreas and biliary tract and is more specific for adenocarcinomas of the pancreas and biliary tract than CA19‐9.