CA 19-9 Antigen
CA 19-9 antigen is a heterogenous glycoprotein, whose elevated levels are observed in the serum of patients with colorectal as well as pancreatic, gastric and liver cancer. Increased levels, but to a lesser extent, are detected in some breast, ovary, lung and head and neck cancers. An assay for 19-9 antigen may be of significant benefit in determining a patient’s course of disease, or response to surgery or other therapies.