Introduction
Alpha-fetoprotein (AFP) is mainly produced in fetal liver tissue; healthy adults have very low levels. In adults, blood AFP is used mainly as a tumor marker and in selected liver disease surveillance—not for routine screening in everyone.
A high AFP does not prove cancer. Hepatitis, cirrhosis, and pregnancy also raise levels. Diagnosis requires imaging, history, and often other markers.
This page focuses on AFP as a tumor marker in adults. Prenatal AFP screening follows separate protocols.
Why this test is done
Alpha-Fetoprotein (AFP) Tumor Marker Test is commonly considered in situations such as:
- Surveillance in high-risk hepatocellular carcinoma (liver cancer) settings
- Monitoring some germ cell tumors (such as testicular cancer)
- Part of long-term liver disease tumor screening when clinically indicated
- Assessing treatment response or recurrence in known AFP-producing tumors
- Further evaluation after abnormal liver imaging in selected patients
How the test is done
- Blood is drawn from a vein and measured in the laboratory.
- Other tumor markers (beta-hCG, LDH) may be ordered together for germ cell tumors.
- The draw takes a few minutes; results return in hours to days.
- Serial measurements track trends during surveillance or treatment.
Preparation and precautions
- Fasting is usually not required—follow lab instructions.
- For prenatal use, accurate gestational dating is essential—this page emphasizes adult tumor marker use.
- Report liver disease, cancer history, and current treatments.
- Mention recent biopsy or imaging that might affect interpretation.
Understanding results
Your clinician interprets lab or imaging ranges together with your symptoms. Online “normal values” do not always apply to your case.
- Reference ranges differ by lab; pregnancy has distinct ranges.
- High values may prompt ultrasound, CT, or MRI and repeat testing.
- Declining AFP during treatment can support response monitoring.
- Normal AFP does not fully exclude cancer—clinical context remains key.
Risks or limitations
- Minor blood draw risks: pain, bruising, lightheadedness.
- Screening-related anxiety or false alarms.
- Acting on a single elevated value without full workup can lead to unnecessary tests.
- Compare trends carefully—lab methods differ.
After the test
- Press on the puncture site; keep the bandage on briefly.
- If results are unexpected, follow scheduled follow-up rather than panicking.
- Abnormal prenatal screening may lead to genetic counseling—separate pathway.
- Do not label yourself with cancer from the report alone.
Frequently asked questions
Does a high AFP always mean cancer?
No. Liver inflammation, cirrhosis, and other conditions raise AFP. Imaging and specialist review are needed.
Why is AFP used in pregnancy?
At specific weeks it may screen for neural tube defects and some chromosomal risks—it is not a diagnostic test by itself.
How often should AFP be checked for liver cancer surveillance?
Interval depends on risk and guidelines. Your hepatology or oncology team sets timing.
Important caution
This article is general health information. It is not personal medical advice or a prescription.
Your clinician decides whether you need this test, how to prepare, and what the results mean. If you have emergency symptoms, go to hospital without waiting for a lab report.