Combined determination of serum CA 19-9 and tissue polypeptide antigen: why no improvement in pancreatic cancer diagnosis?

CA 19-9 and tissue polypeptide antigen (TPA) were determined in the sera of 28 control subjects, 29 patients with pancreatic cancer, 26 with chronic pancreatitis and 62 with benign and malignant extra pancreatic diseases in order to compare their usefulness in diagnosing pancreatic cancer, to verify whether the combined assessment of the two indices could improve the results given by a single parameter and to speculate on the role of liver dysfunction in increasing their serum levels. The sensitivity, specificity and accuracy of CA 19-9 and TPA in diagnosing pancreatic malignancy were: 76, 85 and 61% for CA 19-9 and 79, 52 and 32% for TPA. The receiver-operating characteristic curves showed that CA 19-9 and TPA similarly discriminate pancreatic cancer from controls and chronic pancreatitis, while CA 19-9 is more useful than TPA in differentiating pancreatic malignancy from benign and malignant extra pancreatic abdominal diseases. TPA did not seem to add further information as compared to CA 19-9 alone when both markers were combined. Liver dysfunction may contribute to increasing serum levels of both markers.