AFP is used as a tumor marker to help detect and diagnose cancers of the liver, testes, and ovaries. Though the test is often ordered to monitor people with chronic liver diseases such as cirrhosis, chronic hepatitis B or hepatitis C because they have an increased lifetime risk of developing liver cancer. If a person has been diagnosed with hepatocellular carcinoma or another form of AFP-producing cancer, an AFP test may be ordered periodically to help monitor the person's response to therapy and to monitor for cancer recurrence.
An AFP-L3% is sometimes also ordered to compare the amount of the AFP variant called AFP-L3 to the total amount of AFP. The test is used to help evaluate the risk of developing hepatocellular carcinoma, especially in those with chronic liver disease, and also to evaluate response of hepatocellular carcinoma to treatment.