CA 19-9 in non-neoplastic liver diseases. A clinical and laboratory study.

CA 19-9 is a tumor marker with frequent false-positive results in pancreatic and hepatobiliary diseases. This study was carried out to evaluate the behaviour of CA 19-9 in 159 patients with benign diffuse hepatic disease, 85 cirrhotics and 74 non-cirrhotics, who underwent a thorough clinical and laboratory evaluation. CA 19-9 was correlated with numerous clinical and biochemical features of liver diseases: bilirubin and alkaline phosphatase activity were the most reliable predictors of the CA 19-9 concentrations. There were abnormal concentrations of CA 19-9 in 34.6% of the 159 patients and in 47.1% of the 85 cirrhotics. Because of the large number of abnormal values and the high concentrations attained in some of them, the cut-off used in patients with diffuse hepatic disease needs to be set at more than twice the basal level, thus allows only 10% of false positives. Even higher values are required for cirrhotic or icteric patients. The results indicate that cholestasis plays an important role in causing the raised CA 19-9 in these patients, although there were also abnormal concentrations in normobilirubinemic patients.