Useful For

CA 19-9 is a tumor-associated antigen that is reactive with an antibody that was produced in response to immunization with a human colon cancer cell-line. Although the antibody was derived from a colon cancer cell-line, studies have found assays for CA 19-9 more useful in the diagnosis and management of patients with pancreatic cancer than colon neoplasia.  CA 19-9 has also been shown to be a more sensitive and specific marker of pancreatic cancer than other serologic markers.  Very little of the CA 19-9 antigen is found in the blood of normal patients or those with benign disorders, but most patients with pancreatic cancer have elevated levels of CA 19-9. Many published studies have shown that patients on various therapeutic regimens with clinically stable or responsive disease had stable or decreasing serum CA 19-9 levels, whereas patients with progressive disease had rising serum levels of CA 19-9.

The clinical management of pancreatic cancer is extremely difficult with most pancreatic cancers having metastasized by the time of diagnosis. Treatment consists of surgical intervention, radiation therapy, chemotherapy and palliative care measures as well as nutritional management. Monitoring the progression of disease is critical in the management of this disease. Therefore, the serial monitoring of CA 19-9 levels as an adjunct to imaging and clinical assessment is valuable in the management of pancreatic cancer patients.