Alpha-fetoprotai n (AFP) is a 68kD glycoprotein composing of 591 amino acids and 4% carbohydrate residues. It is the main protein produced by yolk sac and liver during early fetal development, then it decreased significantly by age 1 and should only present a low level in adults.
Liver damage and certain cancers can increase AFP levels obviously. AFP is produced whenever liver cells are regenerating. Moderately elevated AFP level is often found in alcoholic cirrhosis, acute or chronic hepatitis. In this case, AFP test is used to monitor people with these liver diseases since they have higher risks ending up with liver cancer. Doctors may combine this test with imaging studies to detect liver cancer in its earliest stages.
Very high concentrations of AFP may be produced by certain tumors. This characteristic makes the AFP test useful as a tumor marker. Elevated AFP level is found in most people with a type of liver cancer called hepatocellular carcinoma,
together with cancers of the testes and ovaries.
The higher the preoperative AFP level is, the poorer the treatment of HCC.