Alpha-fetoprotein cannot be used as the only criterion for diagnosing liver cancer

Alpha-fetoprotein (AFP) was first detected in pregnant women. It is secreted by actively proliferating fetal cells. Later, it was found in clinical practice that it has a certain relationship with actively proliferating liver cancer cells. Therefore, it is used as a screening indicator for early liver cancer and plays an important role in the diagnosis of liver cancer. However, it should be noted that elevated AFP cannot be used as the only criterion for the diagnosis of liver cancer.

AFP is a special protein in the human blood during the embryonic period. It is synthesized by the rough intracellular ribonucleic acid granules in the liver cells. After the fetus is born, its AFP concentration decreases and returns to normal within a few months to a year. The liver cells of normal adults do not have the ability to synthesize AFP, so the AFP content in the serum is extremely low. Clinically, in addition to hepatocellular carcinoma, AFP can be significantly increased. It is also found in pregnancy, embryonic cancers such as testicular cancer, ovarian cancer, and a very small number of stomach, pancreatic, bile duct, and colorectal cancers.

Elevated serum AFP is the most important marker for hepatocellular carcinoma, with a positive rate of 60% to 70%. If serum AFP is continuously greater than 400ng/ml for more than 4 weeks and transaminase is normal, the prevalence of liver cancer is high. However, elevated AFP alone cannot confirm liver cancer, and a diagnosis of liver cancer cannot be made, because AFP has variants and can also be elevated in patients without liver cancer.

Elevated alpha-fetoprotein levels caused by non-cancerous liver diseases can be identified with the help of AFP variant testing. For example, elevated concanavalin A-bound alpha-fetoprotein (AFP) can be seen in hepatocellular carcinoma and cirrhosis, while elevated concanavalin M-unbound alpha-fetoprotein (AFP) is more common in embryonal carcinoma and liver cancer.