Ca 19-9, Serum

What is CA 19-9, Serum test?

CA 19-9, Serum is a blood test that measures the level of cancer antigen 19-9, a tumor marker often elevated in pancreatic and certain gastrointestinal cancers.

Why consider CA 19-9, Serum test?

It is mainly used to monitor treatment response, track disease progression, and detect recurrence rather than for screening or diagnosis.

Elevated values can also be seen in benign conditions like pancreatitis, gallstones, or liver disease, so results must be interpreted with clinical and imaging correlation. Serial measurements over time are more reliable than a single result

Who should get this CA 19-9, Serum test?

• Individuals diagnosed with cancers known to elevate CA 19-9—most commonly pancreatic adenocarcinoma, and sometimes cholangiocarcinoma, gastric, colorectal, and other GI tumors—when a baseline and serial monitoring will influence care.
• Not recommended for screening asymptomatic individuals or as sole diagnostic evidence, given limited specificity and that some people genetically cannot produce CA 19-9 even with cancer (Lewis antigen–negative).

More Information: CA 19-9, Serum test

Cancer antigen generally refers to a tumor marker—substances made by cancer cells or by normal cells in response to cancer. This can be measured in blood, body fluids, or tissue to help with diagnosis support, therapy selection, monitoring response, and detecting recurrence. These include protein markers like CEA, CA 19-9, CA-125, PSA, and AFP, as well as genomic markers such as specific mutations or fusions used to guide targeted therapy.

OTHER NAMES: Cancer Antigen 19-9, Carbohydrate Antigen 19-9, CA 19-9 tumor marker test, Pancreatic cancer tumor marker,