CA 72-4

What is CA 72-4?

CA 72-4, also known as TAG-72, is a mucin-type glycoprotein found on the surface of certain tumor cells. In adults without disease, the amount in the blood is usually quite low. Because its blood level can rise particularly in gastric cancer and in mucinous tumors of the ovary, it is used as a tumor marker.

As with other tumor markers, CA 72-4 is not used on its own for screening or for a definitive diagnosis; moreover, it can also rise in some benign conditions. Doctors usually evaluate this test together with other markers such as CEA and CA 19-9 to obtain a more complete picture. The measurement is performed on serum, and the result may vary slightly depending on the immunoassay method used. For this reason, the real value of the test lies in comparing measurements taken in the same person over time.

When is a CA 72-4 test ordered?

The main use of the test is to monitor the effect of surgery or drug treatment, and the subsequent course of the disease, in patients diagnosed with gastric cancer. In some ovarian tumors, it can provide information in addition to CA 125. It is not a suitable test for gastric cancer screening in people without symptoms; methods such as endoscopy are the mainstay for evaluating stomach complaints.

Because not every marker rises in every patient with gastric cancer, doctors may personalize the monitoring plan based on the values at diagnosis. A marker that is elevated at the outset may be the one that provides the most information during follow-up.

• Establishing a baseline value before treatment in gastric cancer
• Monitoring the response to surgery or drug treatment
• Follow-up for recurrence of the disease after treatment
• Complementary assessment alongside CA 125 in mucinous ovarian tumors
• Use together with other markers in monitoring colon cancer

How do you prepare for a CA 72-4 test?

No fasting period is required before a CA 72-4 test. Because certain medicines, dietary supplements and coexisting rheumatic diseases can affect the value, it is important to report all the products you use and any known conditions. High-dose supplements containing biotin (vitamin B7) can also alter the result with some measurement methods.

Blood is drawn from a vein in the arm in a brief procedure, and in the laboratory it is centrifuged to separate the serum. For values to be compared meaningfully during follow-up, it is important that the measurements are performed with the same method. If you are recovering after surgery, our nurse can draw the blood at your home or workplace.

What does a CA 72-4 result mean?

A high CA 72-4 value does not by itself mean a diagnosis of cancer. The value can also rise in conditions such as pancreatitis, liver cirrhosis, some lung and rheumatic diseases, ovarian cysts, benign breast diseases and benign gastrointestinal diseases; in such benign conditions, the increase is usually mild. For this reason, an unexpected elevation is generally evaluated with a repeat measurement after a certain interval, together with other findings.

In people being monitored for gastric cancer, values that fall with treatment are considered a positive sign, while a sustained rise during follow-up may lead the doctor to plan further investigations. A normal result, on its own, does not show that the disease is absent. The level considered normal may differ depending on the assay kit; age and sex can also affect interpretation, and the range of the laboratory that performs this test is shown separately on this page. Your CA 72-4 result should be considered as a whole, together with your symptoms and other tests, and must be interpreted by your doctor.