What is an AFP (alpha-fetoprotein) tumor marker test?
AFP stands for alpha-fetoprotein. It is a protein made in the liver of a developing baby. AFP levels are usually high when a baby is born, but fall to very low levels by the age of 1. Healthy adults should have very low levels of AFP.
An AFP tumor marker test is a blood test that measures the levels of AFP in adults. Tumor markers are substances made by cancer cells or by normal cells in response to cancer in the body. High levels of AFP can be a sign of liver cancer or cancer of the ovaries or testicles, as well as noncancerous liver diseases such as cirrhosis and hepatitis.
High AFP levels don’t always mean cancer, and normal levels don’t always rule out cancer. So an AFP tumor marker test is not usually used by itself to screen for or diagnose cancer. But it can help diagnose cancer when used with other tests. The test may also be used to help monitor the effectiveness of cancer treatment and to see if cancer has returned after you’ve finished treatment.
Other names: total AFP, alpha-fetoprotein-L3 Percent
What is it used for?
An AFP tumor marker test may be used to:
- Help confirm or rule out a diagnosis of liver cancer or cancer of the ovaries or testicles.
- Monitor cancer treatment. AFP levels often go up if cancer is spreading and go down when treatment is working.
- See if cancer has returned after treatment.
- Monitor the health of people with cirrhosis or hepatitis.
Why do I need an AFP tumor marker test?
You may need an AFP tumor marker test if a physical exam and/or other tests show there is a chance you have liver cancer or cancer of the ovaries or testicles. Your provider may order an AFP test to help confirm or rule out the results of other tests.
You may also need this test if you are currently being treated for one of these cancers, or recently completed treatment. The test can help your provider see if your treatment is working or if your cancer has come back after treatment.
In addition, you may need this test if you have a noncancerous liver disease. Certain liver diseases can put you at a higher risk of getting liver cancer.
What happens during an AFP tumor marker test?
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
Will I need to do anything to prepare for the test?
You don’t need any special preparations for an AFP tumor marker test.
Are there any risks to the test?
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
What do the results mean?
If your results show high levels of AFP, it may confirm a diagnosis of liver cancer, or cancer of the ovaries or testicles. Sometimes, high levels of AFP can be a sign of other cancers, including Hodgkin disease and lymphoma, or noncancerous liver disorders.
If you are being treated for cancer, you may be tested several times throughout your treatment. After repeated tests, your results may show:
- Your AFP levels are increasing. This may mean your cancer is spreading, and/or your treatment is not working.
- Your AFP levels are decreasing. This may mean your treatment is working.
- Your AFP levels have not increased or decreased. This may mean your disease is stable.
- Your AFP levels decreased, but then later increased. This may mean your cancer has come back after you’ve been treated.
Is there anything else I need to know about an AFP tumor marker test?
You may have heard of another type of AFP test that is given to some pregnant women. Although it also measures AFP levels in the blood, this test is not used in the same way as an AFP tumor marker test. It is used to check for the risk of certain birth defects and has nothing to do with cancer or liver disease.