AFP Blood Test (Alpha-fetoprotein Blood Test)

When testing for liver cancer (hepatocellular carcinoma, or HCC), the most common method used is a blood test known as alpha-fetoprotein or AFP. This is a kind of protein that immature liver cells in the fetus usually produce. Infants will usually have high levels of AFP, but these fall down to normal levels within their first year. However, high levels of AFP are not normally seen in adults (high levels are over 500 nanograms).

When a high level of AFP is detected in cases where this is due to HCC, the higher the levels the more developed the disease. The AFP reading is also used to measure the patient’s response to treatment. Once the HCC is removed surgically, the AFP measurement should return to normal.

Other reasons for high levels of AFP include HCC, cancer of the testes or ovaries, or cancer in the liver that originated in other organs of the body. Normal levels of AFP are usually below 10 ng. Mild or moderate increases in the level can also be due to hepatitis, or chronic and acute liver diseases.

Having a high level of AFP does not necessarily mean a patient will have HCC, though they will be at high risk of developing the condition. And of those that do have HCC, elevated AFP levels are usually seen in about 60% of these patients, meaning that the rest have normal levels of the protein.

There are also other tests for HCC, though these are not widely used. These can include des-gamma-carboxyprothrombin (DCP), and tests for other enzymes that are produced by liver cells. AFP is very useful in diagnosing HCC, but as mentioned above is not completely fail-safe, meaning that a much more accurate picture can be gained by combining these blood tests.