CA 19-9 and CA 50 in benign and malignant pancreatic and biliary diseases

Serum concentrations of the CA 19-9 and CA 50 antigens were determined in 129 patients with malignant and benign biliary and pancreatic diseasse. Values for the two markers were highly correlated (P <0.001). The concentrations of CA 19-9 and CA 50 were positive in 84.6% and 80.7% of patients with pancreatic cancer, respectively. The overall specificity of CA 19-9 (92.4%) was slightly higher than that of CA 50 (88.5%). The sensitivity of CA 50 (91.3%) was greater than that of CA 19-9 (73.9%) in patients with diseases of the biliary tract. Elevated concentrations of CA 19-9 (12.9%) and CA 50 (38.2%) were also found in a number of cases with benign disease, especially in patients with obstructive jaundice. These data suggest that both CA 19-9 and CA 50 can be useful markers of pancreatic cancer in nonjaundiced patients. The joint use of the two markers does not yield a better diagnostic resolution than the use of either one alone.