Summary

• AFP (Alpha-fetoprotein) is a tumour marker and a prenatal screen in pregnancy. 
• During pregnancy, AFP is measured as part of a maternal serum screening test.
• Abnormal AFP levels can indicate the foetus has a condition such as spina bifida or Down syndrome.
• Levels of AFP can be high in the blood of someone who has liver cancer, ovarian cancer or cancer of the testicles and less often, other cancers. 
• An AFP tumour marker test cannot be used on its own to screen for or diagnose cancer because other conditions can cause AFP levels to rise and AFP levels can be normal in individuals who have these cancers.
• AFP is most useful to check how well cancer treatment is working and to keep a watch that the cancer has not returned after treatment.
• AFP levels are expected to go up if a cancer is growing and go down when treatment is working.

What is AFP?

Cancer cells

AFP is made by certain cancers. It is a protein that stimulates cancer cells to grow while stopping them from dying. It also helps a cancer to spread from where it first started to other parts of the body. This process is called metastasis.

Normally, in someone who is healthy, AFP is hardly detectable in a blood sample, but levels can be high when there are tumour cells in the body. AFP testing is used to help investigate liver, ovarian and testicular cancers. Less often, AFP levels can be raised by other cancers including stomach, bowel, lung, breast and lymphoma.

Pregnancy

AFP testing is also used in pregnancy. Large amounts of AFP are produced by the developing baby, but levels gradually decrease to low soon after birth.

Why get tested?

As a tumour marker

Our cells have a lifespan – they get old and die off. Before they die, they copy themselves and this can lead to mistakes being made when genes are copied. Gene mutations occur all the time. Normally, our immune system gets rid of these copying mistakes but as we age it gets less good at this. In cancer, gene mutations cause cancer cells to grow uncontrollably creating a tumour.

AFP is a tumour marker. Tumour markers are compounds that are made by cancer cells or by normal cells in response to cancer.  

High levels of AFP can indicate there is a cancer. However, it cannot be used on its own to screen for or diagnose cancer because other conditions can also increase AFP levels. Chronic liver disease such as hepatitis and cirrhosis can cause AFP levels to rise. On the other hand, some people who have liver, ovarian or testicular cancer have normal AFP levels.

When used with other tests and imaging an AFP tumour marker test may be used to confirm or rule out a cancer diagnosis. It is most useful in monitoring your response to treatment to make sure that as the cancer is treated, AFP levels return to normal. It can also help in prognosis, predicting how a cancer may behave over time. Over the longer term, it can help check to make sure that your cancer has not come back.

In pregnancy

AFP can also be used in pregnancy to screen for the chance of a baby having a disorder such as Down syndrome, Turner syndrome, spina bifida or anencephaly. Although adults have very little AFP in their blood, it is produced in large amounts by the developing baby during pregnancy. Soon after birth, the baby’s AFP drops to very low levels. AFP levels are higher in multiple births (twins and triplets).

AFP has become less commonly used as a screening test with the advent of more accurate first trimester and non-invasive prenatal screening tests.

Having the test

Sample

Blood.

Any preparation?
None.

Your results

AFP is helpful in diagnosing and monitoring cancer, but it cannot be used on its own. Having high AFP levels may be a sign of cancer but this does not mean you have cancer or that you will get cancer. Your medical team will need to use your medical history and other test results including imaging to make a diagnosis.

If your AFP levels are normal, you are less likely to have cancer, but it does not rule out cancer because some people with cancer have normal AFP levels.

A very high level or a sudden increase in AFP can be an early sign of cancer. In general, the higher the AFP level in someone who has cancer, the bigger the tumour. This means, levels can show at what stage your cancer is and help in deciding the best treatment.

Monitoring treatment

If you have been diagnosed with cancer, and have surgery, radiation and/or other treatment regular testing for AFP can help to monitor your response to treatment.

AFP levels can go up immediately after treatment due to the breakdown of tumour cells, but they will go down afterwards.

AFP has a half-life of five to seven days, which means that levels should go down over the 25 to 30 days following treatment.

AFP can also be measured long term to make sure your cancer has not come back.

Liver disease (chronic hepatitis or cirrhosis)

If you have a long-lasting liver disease like chronic hepatitis or cirrhosis you may need regular tests to check for liver cancer. Higher levels of AFP are common with these conditions, and this does not necessarily indicate cancer. If your AFP suddenly rises, or if it is very high, your medical team will order more tests and imaging such as ultrasound, CT scan or MRI scan.

Cancer of the testicles

In testicular cancer, levels of AFP are measured before the testicles are removed to help establish baseline levels for treatment. Other testicular cancer markers such as beta-hCG and LD can also be measured.

Questions to ask your doctor

The choice of tests your doctor makes will be based on your medical history and symptoms. It is important that you tell them everything you think might help.

You play a central role in making sure your test results are accurate. Do everything you can to make sure the information you provide is correct and follow instructions closely.

Talk to your doctor about any medications you are taking. Find out if you need to fast or stop any particular foods or supplements. These may affect your results. Ask:

• Why does this test need to be done?
• Do I need to prepare (such as fast or avoid medications) for the sample collection?
• Will an abnormal result mean I need further tests?
• How could it change the course of my care?
• What will happen next, after the test?

More information

Pathology and diagnostic imaging reports can be added to your My Health Record.

You and your healthcare provider can now access your results whenever and wherever needed. Get further trustworthy health information and advice from healthdirect.