Patient education: CA 19-9 test (The Basics)

What is a CA 19-9 test? — 

This is a type of blood test. It measures the level of CA 19-9 in the blood.

CA 19-9 is a protein in the blood that goes up when a person has certain types of cancer. Examples include cancer of the esophagus, stomach, pancreas, gallbladder, or bile ducts. Other health problems besides cancer, such as gallstones, can also cause CA 19-9 to rise.

Why might I get a CA 19-9 test? — 

Your doctor or nurse might want you to have a CA 19-9 test to:

●Help figure out if your symptoms are caused by cancer or another condition

●See how treatment for cancer or another health problem is working, and make decisions about treatment

●Monitor you over time to see if cancer comes back

How do I prepare for a CA 19-9 test? — 

You need to get a "blood draw." Your doctor or nurse will tell you where to go for this.

It might help to wear a short-sleeve shirt to your blood draw appointment. This makes it easier for the person drawing your blood to get to your arm.

What happens during a blood draw? — 

A needle is used to take a small amount of blood from your arm (figure 1). Collecting the blood only takes a few minutes. The blood is then tested in a lab.

Tell the person who takes your blood:

●If you take "blood thinner" medicines or if you have a bleeding problem – They will make sure your bleeding is under control before you leave.

●If you have a latex allergy – Some of the supplies used for blood draws might contain latex.

●If you have a preferred arm to use

Most of the time, getting blood taken does not cause problems. You might have a little soreness or bruising where the needle went in.

What do my results mean? — 

Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.

If the results show your CA 19-9 level is high, your doctor or nurse will talk to you about what to do next. They might need to do more tests to figure out the cause.

If you do have a health problem, your doctor will work with you to come up with a plan for treatment.

More on this topic

Patient education: Esophageal cancer (The Basics)
Patient education: Stomach cancer (The Basics)
Patient education: Pancreatic cancer (The Basics)
Patient education: Gallbladder cancer (The Basics)
Patient education: Cholangiocarcinoma (The Basics)
Patient education: Gallstones (The Basics)

Patient education: Pancreatic cancer (Beyond the Basics)
Patient education: Gallstones (Beyond the Basics)