Carbohydrate Antigen 50 (CA50)

Carbohydrate antigen 50 (CA 50) is a tumor marker that increases in many malignancies, especially in carcinoma of the digestive tract. False-positive results occur in benign liver disease.

Significant correlations with some liver tests were found, especially transaminases, and at lower degrees with cholestatic parameters. Despite the previously reported relation with cholestasis, especially in biliary diseases, the CA 50 serum levels of the authors' cirrhotic patients appeared to be more closely related to cytolysis, according to the results of several statistical tests, including multivariate analysis.

Because of the percentage and the levels of the abnormal results, this antigen cannot be used as a tumor marker in cirrhotic patients. Cytolysis seems to have a pathogenetic role in the increase of CA 50, at least in cirrhosis.