A study of pancreatic secretory and intracellular enzymes in pancreatic cancer tissue, other gastrointestinal cancers, normal pancreas and serum.

Serum and tumour tissue extracts from patients with pancreatic exocrine adenocarcinoma and a number of other gastrointestinal tumours were examined for digestive and intracellular enzymes or tumour associated variants by cellogel electrophoresis. Enzymes were identified within the gel by their specific catalytic activities. Normal serum and extracts of normal pancreas were also studied. All the pancreatic secretory enzymes were present in extracts of normal pancreas; their levels were markedly reduced in tumour extracts and no characteristic isozymes were found. Alkaline phosphatase, carbonic anhydrase and a number of carbohydrate metabolising enzymes were present in all extracts; tumour associated isozymes were not consistently identified. These findings suggest that most human pancreatic exocrine cancers do not produce pancreatic secretory enzymes or intracellular isozyme variants, and that the identification of these enzymes or their isozymes is unlikely to be of practical diagnostic value.