The evaluation of CA 19-9 antigen level in the early detection of pancreatic cancer. A prospective study of 866 patients.

To establish if CA 19-9 could detect early pancreatic cancer, we measured its serum concentration in 866 patients admitted for benign diseases and observed for 2 years. All patients with an elevated CA 19-9 level (greater than 40 units (U)/ml) were submitted to a computed tomography (CT) scan of the pancreas. The CA 19-9 level was increased in 117 patients. One hundred fifteen of these 117 patients had false-positive elevations. The CA 19-9 concentration was elevated mostly in benign hepatobiliary diseases. In this group of patients, CA 19-9 was correlated to alkaline phosphatase values. Eleven patients showed an elevated CA 19-9 level for 10 months without any malignancy developing. One patient had a normal CA 19-9 concentration 8 months before clinical signs of pancreatic carcinoma developed. We conclude that CA 19-9 measurement is of no value for the early detection of this malignancy.