Alpha-fetoprotein (AFP)
Alpha-fetoprotein (AFP) is a protein normally produced by the liver and yolk sac of a developing fetus. AFP levels decrease soon after birth.
Why an AFP test is done
An AFP test may be done to:
- help diagnose certain liver disorders
- help diagnosis and monitor a person’s response to treatment for certain cancers
- primary liver cancer (hepatocellular cancer)
- testicular cancer (non-seminomatous type)
- ovarian cancer (germ cell type)
- check if these cancers have come back (recurred) after treatment
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How an AFP test is done
An AFP test is usually done in a private laboratory or hospital laboratory. No special preparation is usually needed.
- AFP is usually measured by a blood test.
- The sample is sent to a laboratory to be analyzed by special machines.
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What the results mean
An increased AFP may be due to:
- non-cancerous conditions
- benign liver conditions (such as cirrhosis or hepatitis)
- pregnancy
- some rare inherited disorders (such as ataxia-telangiectasia)
- certain cancers
- testicular cancer
- ovarian cancer
- bile duct cancer
- stomach cancer
- pancreatic cancer
- liver metastases
In cancerous conditions:
- A decrease in, or return to normal of, AFP levels may mean that the cancer has responded well to treatment.
- An increase in AFP levels may mean that the cancer is not responding well to treatment, is still growing or is coming back (recurring).
- A slight increase may not be significant. The doctor looks at trends in the increase over time.
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What happens if a change or abnormality is found
The doctor will decide if more tests, procedures, follow-up care or additional treatment is needed.
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