Serum levels of pancreatitis-associated protein in digestive diseases with special reference to gastrointestinal cancers.

The serum levels of pancreatitis-associated protein (PAP) were measured in 196 patients with digestive diseases and 15 healthy subjects by an enzyme-linked immunosorbent assay. The serum PAP levels were significantly elevated in the patients with gastric, colorectal, biliary tract, hepatocellular, or pancreatic cancers compared with the healthy subjects. After curative resection of the tumor, serum PAP levels were significantly decreased. The serum PAP levels were not related to clinicopathological factors except for the tumor size of pancreatic cancer. There were some cases of PAP-positive and carcinoembryonic antigen (CEA) or carbohydrate antigen (CA) 19-9 -negative gastric and colorectal cancers. The serum PAP levels were also significantly elevated in the patients with acute pancreatitis compared with those in not only the healthy subjects but also the patients with chronic pancreatitis. The peak PAP levels were significantly correlated with the severity of acute pancreatitis and reflected the clinical healing of the disease. The peak of serum PAP was significantly delayed compared with those of other pancreatic enzymes. These results suggest that the increase of serum PAP levels in patients with gastrointestinal cancers reflects an ectopic expression of PAP in cancer cells and that increased serum levels of PAP in acute pancreatitis are correlated with the disease severity and are prolonged than those of other pancreatic markers.