Tumour-associated trypsin inhibitor in the diagnosis of pancreatic carcinoma.

The serum values of tumour-associated trypsin inhibitor (TATI) were measured in a prospective series of 97 patients with jaundice, 36 patients with unjaundiced cholestasis and 21 patients with suspicion of chronic pancreatitis or a pancreatic tumour, to assess its value in diagnosing pancreatic cancer. There were altogether 15 patients with cancer of the pancreas and 2 patients with cancer of the papilla of Vater. The highest serum TATI values were noticed in patients with choledocholithiasis, and raised values were also seen in patients with malignant disease of the liver or bile ducts. In the patients with pancreatic cancer, chronic pancreatitis or benign liver disease, the serum TATI values showed lower levels. The sensitivity of TATI in diagnosing pancreatic cancer was 41.1% with a specificity of 63.5% and an efficiency of 61.0%. In comparison to carcinoembryonic antigen (CEA), carbohydrate antigens CA 50, CA 242, tissue polypeptide antigen and tissue polypeptide-specific antigen, TATI showed a lower diagnostic value. When TATI was analysed in combination with the other markers (two tests positive), the combination of CEA with TATI reached the highest specificity (95.6%), efficiency (89.6%) and positive likelihood ratio (9.3). The results suggest that the diagnostic value of TATI is inferior to that of the established markers, but because of its different nature, it may be of help when used in combination as a complementary serum tumour marker in the diagnosis of pancreatic cancer.