Alpha Fetal Protein is an abbreviation of Alpha Fetal Protein, which means fetal protein, or fetal nail globule. It is a special glycoprotein synthesized by hepatocytes during the embryonic period, which can promote rapid proliferation of fetal liver tissues, so the content in fetal blood is high, but it basically disappears about 1-4 weeks after birth, and the content in adult blood is very little. Above 400ug/L is considered a high concentration positive. A positive AFP sometimes occurs months to a year earlier than a positive imaging test, which can buy patients valuable and perhaps fateful treatment time! The value of AFP for early diagnosis of liver cancer is a rare feature that makes AFP superior to other cancer markers. By detecting AFP, screening the population or diagnosing liver cancer clinically and taking surgery or corresponding treatment, medical professionals have been able to prolong the lives of many liver cancer patients and even eventually defeat liver cancer. Literature also confirms that 70-90% of patients with primary hepatocellular carcinoma are positive for AFP, and there is usually a correlation between the serum concentration of AFP and the size of the mass and the degree of differentiation of the tumor cells. Normal hepatocytes do not produce AFP, while cancerous hepatocytes regain the ability to synthesize AFP, and the concentration of AFP can increase progressively with the crazy multiplication of cancer cells. Therefore, patients with hepatocellular carcinoma have a persistent and high positive AFP concentration over the course of the disease, usually above 400ug/L. However, an elevated AFP level is necessarily a sign of a positive AFP. However, does elevated AFP necessarily mean liver cancer? Not necessarily! This is because there are also the following factors: 1. False positive: No test can be 100% correct, and AFP measurement can also have the problem of false positive, i.e. no liver cancer has occurred but AFP is positive. In this case, AFP should be observed dynamically and combined with imaging and other laboratory tests to exclude it. 2.Benign liver disease: Acute hepatitis, chronic active hepatitis, cirrhosis and other liver diseases, because the virus replicates and proliferates in the liver cells, the liver cells are in the process of damage, repair and regeneration, AFP will be elevated, but the concentration is generally not too high, mostly less than 200ug /L, and with the improvement of hepatitis, AFP also decreases, and then gradually return to normal. AFP elevation is transient and positive at low concentrations. This helps to differentiate AFP from hepatocellular carcinoma, which is a persistent, high level of positivity. However, in a small number of patients with benign liver disease, AFP may also be positive in high concentrations, with values greater than 400ug/L and even up to 6000ug/L, due to persistent and excessive hepatocyte damage and regeneration, and immature differentiation of the regenerating hepatocytes to synthesize large amounts of fetal nail cells. However, if the degree of liver damage is mild (which can be observed by changes in liver enzymes such as ALT and AST) and AFP continues to be positive in high concentration, the occurrence of liver cancer should be highly alerted. 3.Embryonic tumor: Because of the biological characteristics of AFP, AFP may increase during pregnancy or when malignant embryonic tumor of reproductive system (such as testicular teratoma, ovarian cancer, etc.), but then there should be occupying lesions of genital organs without the basis of liver cancer for differentiation. 4.Other: congenital biliary atresia, abnormal tyrosine metabolism, some secondary hepatocellular carcinoma, some benign tumors of liver and other diseases are also reported to have different degrees of AFP elevation. 5.The rise and fall of AFP can be used as an indicator to judge the prognosis of liver cancer or to observe the effect of surgery and various anti-cancer treatments: after the diagnosis of liver cancer and the adoption of surgical resection or various treatments, a significant decrease of AFP indicates that the treatment is effective; if it increases again after the decrease, it indicates that liver cancer has signs of recurrence and metastasis. However, the magnitude of AFP increase is not proportional to the severity of the disease. We should judge the treatment effect of tumor through imaging examination first, and AFP is only a reference.