Tumor marker CA 50 (gastrointestinal tumors)

CA 50 is a sialoglycoprotein detected on the surface of epithelium and in body fluids. As a marker of gastrointestinal tumours, primarily pancreatic cancer, it has a higher diagnostic sensitivity than CA19-9. The main diagnostic value of the CA 50 test is that it is elevated in patients (5-7% of the population) who are negative for the Lewis antigen Le (a-b-) and have no synthesis of CA 19-9, and therefore no increase in the presence of carcinoma.

High levels of CA 50 cancer antigen (up to 100 U/ml and higher) are present in cirrhosis of the liver and pancreas (ca. 18% of patients). The use of the CA 50 cancer antigen does not have the advantages of the CA 19-9 pre-cancerous antigen.