Immunohistochemical staining of pancreatic cancer with CA19-9, KM01, unabsorbed CEA, and absorbed CEA. A comparison with normal pancreas and chronic pancreatitis.

In order to test the effectiveness of CA19-9, KM01, unabsorbed CEA (carcinoembryonic antigen) and absorbed CEA by immunoperoxidase staining, we evaluated the staining distribution, intensity, and cellular localization in pancreatic cancer. The results were then compared with those of normal pancreas and chronic pancreatitis. The positive staining rate of the pancreatic cancer with any of the four tumor markers was higher than that of the normal pancreas. However, all markers except absorbed CEA showed a higher positive staining rate for chronic pancreatitis than for pancreatic cancer. There was no stromal type in normal pancreatic or chronic pancreatitis tissues with any of the four tumor markers. Our findings, therefore, indicate that absorbed CEA is useful in differentiating pancreatic cancer from normal pancreatic tissues. It is not useful in distinguishing chronic pancreatitis, however, unless a specific staining pattern is observed.