AFP is used to detect tumors that mark cancers of the liver, testes, and ovaries. Patients with chronic liver diseases such as cirrhosis or chronic hepatitis B must be monitored at regular intervals because they have a lifetime risk of developing liver cancer. A doctor may order an AFP test, along with imaging studies, to try to detect liver cancer when it is in its earliest, and most treatable, stages. An AFP-L3% test may be ordered by some doctors to help further evaluate the risk of patients with chronic liver disease developing hepatocellular carcinoma in the near future.

If a patient has been diagnosed with hepatocellular carcinoma or another form of cancer, an AFP test may be ordered periodically to help monitor a patient’s response to therapy.

Your physician may order an AFP blood test when he:

suspects that a patient has liver cancer or certain cancers of the testes or ovaries.

is monitoring a patient with chronic liver disease for the emergence of hepatocellular carcinoma or another type of liver cancer.

is monitoring the effectiveness of treatment in a patient who has been diagnosed with and treated for a cancer of the liver, testes, or ovaries.

An AFP-L3% may be ordered to help evaluate the risk of hepatocellular carcinoma when a patient has chronic liver disease. This new test, however, is not widely used and its ultimate clinical utility has yet to be established.

Increased AFP levels can mean liver cancer, cancer of the ovary, germ cell tumor of the testes, cirrhosis, hepatitis, or other cancers (stomach, colon, lung, breast, lymphoma).

With an AFP-L3%, the doctor receives both a total AFP result and the percentage of AFP that is L3. If a patient has chronic liver disease and their AFP and L3% are significantly elevated, then the patient has an increased risk of having or developing hepatocellular carcinoma in the next year or two. Both AFP and AFP-L3% concentrations can be elevated, and fluctuate, in patients with chronic hepatitis and cirrhosis. In these patients, a significant increase in AFP is more important than the actual numerical value of the test result.

In general, the higher the AFP level in patients with cancer, the bigger the tumor. AFP decreases when your body responds to anti-cancer therapy. If AFP does not return to normal within about one month after cancer therapy, some of the tumor may still be present.

Not every patient with increased AFP and AFP-L3% test results has cancer or will develop liver cancer. The AFP and AFP-L3% tests are not diagnostic; they are indicators. They must be used in conjunction with imaging studies to look for malignant tumors when monitoring the patient, or when a doctor suspects that a cancer is present. The tests can provide useful information, but they are not as specific or sensitive as doctors would wish. They should not be used to screen the general population for cancer.

Note that AFP is not always a tumor marker. Because AFP is produced by the fetus, levels are normally higher in pregnant women and in their newborns. For more information on AFP testing during pregnancy, see Triple Screen.