Nowadays, health checkups are becoming more and more popular, and many patients often take their checkup reports and say that when they check their liver function, they find high fetoprotein, and when they go online to Baidu doctors, they find that elevated fetoprotein is an early manifestation of liver cancer. So what exactly is alpha-fetoprotein? What are the causes of high AFP? Is elevated AFP equal to liver cancer? How to further diagnose and treat elevated fetoprotein? Today, we will discuss this topic. I. What is AFP? AFP is a glycoprotein with a molecular weight of 69,000 that is secreted by the infantile hepatocytes in the fetal liver. Normal adult mature hepatocytes do not secrete AFP, and the amount in the blood circulation is very low, usually less than 20 μg/L. When mature hepatocytes become cancerous, the cancerous hepatocytes can re-secrete AFP. In patients with primary liver cancer, serum alpha-fetoprotein is elevated in approximately 80% of patients with hepatocellular carcinoma. Therefore, methemoglobin is the most specific and widely used serum marker for screening and diagnosis of hepatocellular carcinoma. What are the conditions that may lead to elevated fetoprotein? Physiological elevation of AFP: Pregnant women and newborns: AFP is mainly found in the naive hepatocytes in the fetal liver and can enter the maternal blood through the umbilical cord blood, therefore, AFP is elevated in pregnant women during pregnancy. The amount of AFP in maternal blood peaks at 32 weeks (184.6±74.6) ug/L. Thereafter, it gradually decreases with the progress of pregnancy, and gradually returns to normal level after about 3 weeks postpartum. AFP returns to normal about 3 weeks after birth. If AFP is significantly elevated in newborns, it indicates neonatal hepatitis, congenital biliary atresia or embryonic malignancy that can secrete AFP. Pathological elevated AFP: 1. Hepatocellular carcinoma: About 70% of liver cancer patients have elevated AFP in serum, which has high specificity and sensitivity. The incidence rate of liver cancer in China ranks the fifth among malignant tumors and the death rate ranks the second among causes of death of malignant tumors, and the trend is continuously increasing. Liver cancer starts insidiously and develops rapidly, and most of the patients are already in advanced stage when they are detected, so radical surgery cannot be performed and the prognosis is poor. Even some patients with intermediate and advanced stages have undergone radical surgery, the recurrence rate is still high. Therefore, early detection and treatment of hepatocellular carcinoma are crucial to reduce the death rate and prolong the survival of patients. Through the screening of fetoprotein in the physical examination of high-risk groups, combined with imaging, it can diagnose small hepatocellular carcinoma at an early stage and significantly improve the prognosis of liver cancer patients. Myth 1: Methemoglobin is a specific clinical indicator for the diagnosis of primary liver cancer, so does elevated methemoglobin found in physical examination equal to liver cancer? In fact, in the diagnostic criteria for liver cancer promulgated by our Ministry of Health, the diagnosis of primary liver cancer is considered when AFP is greater than 400 micrograms/L for four weeks or greater than 200ug/L for eight weeks, and pregnancy, active liver disease and germinal embryonic tumors are excluded. AFP is not only elevated in patients with primary hepatocellular carcinoma, but is also commonly elevated in many patients with chronic liver disease. Serum AFP is elevated in 15%-58% of patients with chronic hepatitis and 11%-47% of patients with cirrhosis. In patients with acute or chronic active hepatitis, AFP is usually mildly or moderately elevated, usually in the range of 50-300 μg/L. After liver protection and antiviral therapy, serum AFP can be reduced to normal. In contrast, the elevation of alpha-fetoprotein in patients with hepatocellular carcinoma is often persistently elevated, without the process of first elevation and then decrease. Gastrointestinal tumors: Gastrointestinal tract tumors such as gastric cancer, pancreatic cancer, bile duct cancer, etc. can also have different degrees of elevation of AFP, but usually accompanied by other positive tumor markers. The rate of AFP positivity among gastric cancer patients can reach 5%-15%, and these patients have their own clinicopathological characteristics: (1) they are mostly found in middle-aged and elderly men, and are mostly located in the gastric sinus; (2) the early symptoms are not obvious, but the symptoms are usually in the middle and late stages, and the clinical diagnosis is progressive gastric cancer; (3) the malignancy is high, and the pathological typing is mostly low-differentiated adenocarcinoma, which is prone to early lymph node metastasis. 3.Germ cell tumor: Germ cell tumor can also cause elevation of methemoglobin. The sites of onset are mainly located in the sacrococcygeal region, testes, ovaries, pelvis, retroperitoneum, mediastinum, etc. Children: endodermal sinus tumor (yolk sac tumor); men: testicular cancer (seminoma); women: ovarian cancer, teratoma, etc. In 50% of patients with germ cell tumors, AFP can be elevated to varying degrees, but the specificity is not strong and needs to be combined with imaging manifestations and other tumor markers such as CA125, CEA, and β-HCG to confirm the diagnosis. Myth 2: Myth 2: If AFP is not elevated, it is impossible to have liver cancer? 20%-30% of patients with early stage small liver cancer have normal AFP; some patients have continued negative AFP from the onset to the end stage of the disease; negative AFP cannot be used as a criterion to exclude liver cancer. For the high-risk group of liver cancer (mainly chronic liver disease patients), in order to detect liver cancer at an early stage, even if AFP is normal, ultrasound examination should be performed regularly to avoid missing the diagnosis. What should be done if elevated fetoprotein is found? First of all, we need to clarify that elevated fetoprotein does not mean liver cancer, but at the same time, we need to have a sense of worry and actively cooperate with doctors for various examinations to be responsible for our own health. 1.Liver function test: In patients with active hepatitis, elevated AFP is accompanied by abnormal liver function, after liver preservation and antiviral treatment, the change of liver function should be followed up. If fetoprotein does not drop significantly after liver function recovers in one month, further imaging examination is needed to rule out the possibility of hepatocellular carcinoma. 2. Viral hepatitis marker test: Since most of the liver diseases in China are patients with viral hepatitis, with hepatitis B or C infection. Therefore, when we find elevated methemoglobin, we must conduct hepatitis virology examination, especially the virology of HBV and HCV, to clarify whether there is hepatitis virus replication. The commonly used clinical hepatitis virus examination is mainly hepatitis B two-to-one half, HBVDNA, HCVRNA examination, etc. 3.Imaging: Along with serological examination, we need to perform liver ultrasound for occupying lesions. If the diagnosis of liver occupying lesion is unknown by ultrasound, CT or MRI examination can also be performed. Although elevated fetoprotein is not equal to liver cancer, we must go to a regular hospital for relevant examination and timely treatment after clarifying the cause. 2. To prevent and treat liver cancer, we should have regular health checkups. Especially for hepatitis B or C carriers, liver ultrasound test, fetoprotein, liver function and hepatitis virology test should be done once every six months. If the liver function test is abnormal and the virus replicates, antiviral treatment is also needed. 3, eat more protein and vitamin content of food; avoid hard and stimulating spicy food, avoid smoking and alcohol, maintain a healthy lifestyle and eating habits. 4.Actively exercise to enhance physical fitness and keep away from liver disease.