Serum immunoreactive elastase in diagnosis of pancreatic diseases. A sensitive marker for pancreatic cancer.

Diagnostic significance of serum immunoreactive elastase-1 was studied in 137 patients with pancreatic disease, 335 with various nonpancreatic diseases, and 416 healthy controls by using radioimmunoassay. Frequency of abnormally high serum elastase values exceeding 410 ng/dl was 100% in acute pancreatitis (N = 14), 40% in chronic pancreatitis (N = 80), and 72% in pancreatic cancer (N = 43). In pancreatic cancer the mean value of serum elastase in resectable cancer (N = 19) was significantly higher than that in unresectable cancer (N = 24). Sensitivity, specificity, and efficiency of serum elastase in pancreatic cancer were 72.1%, 98.3%, and 95.9% against healthy controls; 72.1%, 85.9%, and 83.6% against nonpancreatic digestive diseases; and 72.1%, 60.0%, and 64.2% against chronic pancreatitis at a cutoff level of 410 ng/dl, respectively. High serum elastase could be a diagnostic clue to detect pancreatic duct obstruction due to pancreatic cancer, although further examination should be done by endoscopic retrograde pancreatography and other imaging studies.