Abnormalities in pancreatic secretory profiles of patients with cancer of the pancreas.

Pancreatic secretory profiles for 11 pancreatic enzymes and proteins were established in nine patients with cancer of the pancreas by analysis of minute-to-minute collections of pure pancreatic juice after sequential administration of secretin and cholecystokinin. Aspiration of pancreatic fluid sufficient for this study was successful in less than one quarter of the patients investigated because of ductal obstruction and/or the effect of the disease on pancreatic exocrine function. Flow rates in patients generally were lower than in healthy individuals, and secretion of total protein, trypsin inhibitor, and activity of digestive enzymes were in the lowest part of or below the normal range. Normal flow rates in four patients precluded ductal obstruction as the sole cause of impaired enzyme secretion. Activity of lysosomal hydrolases in pancreatic juice of these patients, in contrast to that of digestive enzymes, remained within or rose above the normal range. The tumor appeared to have a diametrically opposite effect on the two different groups of enzymes. This is illustrated most dramatically in the form of ratios of lysosomal to digestive enzymes. Virtually all of 10 such ratios were far above the normal average in all patients, and none was below. In an analogous investigation of 25 patients with chronic pancreatitis only three exhibited the ratio pattern characteristic of pancreatic cancer patients. Pancreatic secretory profiles appear to be capable of discriminating between cancer of the pancreas and chronic pancreatitis in a high percentage of cases. Extension and refinement of this approach may facilitate early detection of cancer of the pancreas.