Platform
Company
Immunology & Autoimmune
Review status
Currently under review
Pending specialist review and validation.
Alpha-fetoprotein (AFP) is a protein normally produced by a developing baby’s liver. In children and adults, AFP can be made by certain tumors and by injured or regenerating liver cells. The AFP tumor marker test measures the amount of AFP circulating in your blood.
This blood test helps your care team evaluate liver conditions and some germ cell tumors, such as certain testicular and ovarian cancers. AFP is one piece of the picture, interpreted alongside your history, exam, imaging, and other laboratory tests.
AFP can support the evaluation of a liver mass or chronic liver disease and may help your clinician assess the likelihood of hepatocellular carcinoma. It is also commonly used to track how well treatment is working and to watch for possible recurrence after therapy.
In germ cell tumors, AFP complements other markers to help classify the tumor type and monitor response. Because AFP can also rise with liver inflammation or cirrhosis, and may be normal in some cancers, it is not a stand-alone diagnostic or screening test. Your clinician will decide when to order AFP based on your risk factors, symptoms, and imaging plans.
An AFP result is interpreted in context. Levels can be higher with active hepatitis, cirrhosis, pregnancy, and in newborns, so an isolated elevation does not automatically mean cancer. Likewise, some cancers do not make AFP, so a normal result does not exclude disease if there is a concerning mass or symptoms.
Your care team will consider trends over time, other blood tests, and imaging. A rising pattern may prompt further evaluation, while a stable or falling pattern after treatment can be reassuring. If results are unexpected, your clinician may repeat the test, confirm with the same laboratory method, or add imaging or other markers to clarify the picture.
Reference intervals vary by laboratory, analyzer, methodology, population, and units. The ranges shown here are for education only. Always interpret your results against the reference interval printed on your own lab report.
AFP is naturally high during pregnancy and in newborns, then declines over time. Pregnancy status and a child’s age are essential for correct interpretation.
Active hepatitis, flares in chronic hepatitis B or C, and cirrhosis can raise AFP even without cancer. Results should be read with liver enzymes and imaging.
High-dose biotin supplements can interfere with some immunoassays. Cancer therapies and antivirals can change AFP as tumors or liver inflammation respond.
Hemolysis, severe lipemia, or delayed processing can affect some assays. For monitoring, use similar timing relative to treatments and the same laboratory.
Not all hepatocellular or germ cell tumors produce AFP. A normal AFP does not rule out cancer, and discordant results require imaging correlation.
Different platforms may yield slightly different values. Serial monitoring is most reliable when performed by the same lab using the same method.
References