The AFP (Alpha-Fetoprotein) test measures the level of alpha-fetoprotein in your blood. AFP is a protein that is produced primarily by the liver and yolk sac of a developing fetus during pregnancy, but it is also produced in small amounts by the liver, gastrointestinal tract and other tissues in adults.
Why it’s important:
- Monitor liver health: AFP is commonly used to help monitor liver diseases, such as hepatitis or cirrhosis, and to assess the presence of liver cancer (hepatocellular carcinoma, HCC).
- Detect hepatocellular carcinoma (HCC): AFP is a key marker in detecting liver cancer, particularly in individuals with chronic liver conditions (e.g., cirrhosis, chronic hepatitis B or C).
- Monitor germ cell tumours: AFP levels can be elevated in germ cell tumours, such as testicular cancer or ovarian cancer.
- Fetal health monitoring: During pregnancy, AFP is used to assess fetal health and development as part of the triple or quadruple screening tests to evaluate the risk for conditions like Down syndrome or neural tube defects.
Limitations of AFP Testing:
- Not specific to one condition: Elevated AFP levels are seen in a variety of conditions (both cancerous and non-cancerous), so AFP is not a definitive test for any one disease.
- False negative: Not all liver cancers or germ cell tumours will cause elevated AFP levels, particularly in early stages.
Pregnancy considerations: AFP levels vary during pregnancy, so results need to be interpreted within the context of gestational age and other screening results.
