An AFP-L3% is sometimes ordered to help evaluate the risk of when a person has chronic liver disease or to test the effectiveness of treatment of hepatocellular carcinoma or monitor for its recurrence.
Increased AFP levels may indicate the presence of cancer, most commonly liver cancer, cancer of the ovary, or germ cell tumor of the testicles. However, not every liver, ovarian, or testicular cancer will produce significant quantities of AFP.
Elevated levels may sometimes be seen with other cancers such as stomach, colon, lung, breast, and lymphoma, although it is rarely ordered to evaluate these conditions. Other diseases such as cirrhosis and hepatitis can also cause increased levels.
When AFP is used as a monitoring tool, decreasing levels indicate a response to treatment. If concentrations after cancer treatment do not significantly decrease, usually to normal or near normal levels, then some of the tumor tissue may still be present.
If AFP concentrations begin to increase, then it is likely that the cancer is recurring. However, since AFP can be increased in hepatitis or cirrhosis, AFP levels can sometimes be misleading. If AFP levels are not elevated prior to treatment, then the test will not generally be useful to monitor the effectiveness of treatment or to monitor for recurrence.
When the AFP concentrations of people with chronic liver disease go from normal or moderately elevated to greatly elevated, their risk of developing liver cancer increases. When total AFP and AFP-L3% are significantly elevated, then the affected person has an increased risk of having or developing in the next year or two. However, both AFP and AFP-L3% concentrations can be elevated, and fluctuate, in people with chronic hepatitis and cirrhosis. In these cases, a sharp increase in AFP is more important than the actual numerical value of the test result.
Is there anything else I should know?
Not every person with increased AFP and AFP-L3% test results has cancer or will develop liver cancer. The AFP and AFP-L3% tests are not diagnostic per se; they are indicators. They must be used in conjunction with information from a medical history and physical examination as well as histopathological examination and imaging studies to look for the development of tumors.
Although these tests can provide useful information, they are not as or as healthcare practitioners would wish. AFP can temporarily increase whenever the liver is injured and regenerating, and moderate elevations can be seen with a variety of conditions. Because of this, AFP testing cannot be used solely to diagnose cancer. In addition, not every cancer will produce AFP, so a person could still have cancer even when the AFP is normal. For these reasons, the AFP test should not be used to screen the general population for cancer.
AFP is not only 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 the Second Trimester Maternal Serum Screen.