"Plasma"-type ribonuclease in pancreatic cancer diagnosis: a critical appraisal.

The so-called "plasma" ribonuclease (RNase), described as increased in most patients with pancreatic cancer, was studied in the blood of 92 subjects utilizing the method of Reddi and Holland, to evaluate its reliability in detecting pancreatic tumors. A significant increase of "plasma" RNase was found in pancreatic cancer (p less than 0.01) as compared with controls, non-calcifying chronic pancreatitis (p less than 0.01), calcifying chronic pancreatitis (p less than 0.01), and chronic recurrent pancreatitis (p less than 0.01). Nevertheless increased "plasma" RNase activity was also found in 18/43 patients with chronic pancreatitis, as well as in the majority of the non-pancreatic malignant tumors studied. Furthermore, in 2 out of 22 subjects with pancreatic cancer the enzyme activity was found to be normal. These data suggest that increased "plasma" RNase, although very frequent in pancreatic cancer, is not a marker of pancreatic malignancy.