With the improvement of living standard, physical health is becoming more and more important, and regular medical checkups are increasingly entering the topic of people’s lives. During physical examination, people often include ultrasound, X-ray, ECG, liver and kidney function as the scope of daily physical examination, but neglect the detection of tumor markers. Most tumor patients are found to be in advanced stage and lose the best treatment period. In fact, tumor marker testing is very important for people who have reached a certain grade. Some tumor markers have the function of early detection of tumor, and some can be used as indicators of therapeutic effect observation. 1.How are tumors formed? The formation of tumor is a rather long process. Usually, it takes many years after exposure to carcinogenic substances to cause progressive and severe atypical carcinogenic proliferation of cells in tissues and organs before it evolves into cancer. This period is called the induction period, which is usually as long as 15-30 years. Among them, oncogene is a very important factor, and cancer is only possible after years of long-term exposure to carcinogenic substances in people with oncogene. People without oncogenes may also develop cancer after years of long-term exposure to carcinogenic substances. People with family members suffering from malignant tumors are more likely to carry cancer genes. 2.How to achieve early detection and diagnosis of tumor? Tumor disease is a chronic disease, which will show certain symptoms or signs in the early stage, even if they are not obvious, they are clues for early diagnosis of tumor. The common symptoms and signs are as follows: (1) Local symptoms: pressure symptoms and obstruction symptoms, such as headache, nausea, vomiting, visual disturbance, etc. Pain, tumor causes pain for different reasons, thus the early and late occurrence and degree of pain varies. Pathological secretions, such as bronchial lung cancer with increased sputum and blood clots, rectal cancer with fluid and bloody stool, breast cancer with bloody nipple overflow, kidney cancer and bladder cancer with hematuria, etc. (2) Systemic manifestations: fever, tumor patients mostly have fever, which is caused by insufficient blood supply to the tumor site, necrosis or combined infection. Weakness and wasting are caused by fast growth of tumor, high energy consumption, decreased appetite and poor digestion of patients. Anemia, caused by chronic recurrent bleeding due to tumor, hematopoietic disorders or malabsorption of hematopoietic substances. Cachexia, caused by chronic consumption, insufficient intake, recurrent attacks and gradual deterioration of the disease, is a state of general cachexia. With the emergence of advanced instruments and technologies, more and more early tumors can be diagnosed early, such as the detection of tumor markers is one of them. 3.What are the common tumor marker tests? Certain tumors can secrete specific chemicals during the process of development, which are called tumor markers. Monitoring the appearance of these tumor markers in blood and their changes can help diagnose certain specific tumors. There are 18 tumor markers that are commonly used in clinical practice. The abnormal elevation of one tumor marker often indicates the occurrence of relative tumors, such as abnormal elevation of alpha-fetoprotein (AFP) in primary liver cancer; abnormal elevation of carcinoembryonic antigen (CEA) in stomach, intestine and lung tumors; abnormal elevation of prostate-specific antigen (PSA) in prostate tumors; abnormal elevation of glycoprotein antigen 153 (CA153) in breast tumors; abnormal elevation of glycoprotein antigen 125 (CA125) in ovarian tumors. In ovarian tumors, glycoprotein antigen 125 (CA125) is often abnormally elevated; in pancreatic tumors, glycoprotein antigen 199 (CA199) is often abnormally elevated; in stomach tumors, glycoprotein antigen 724 (CA724) is often abnormally elevated; in patients with nasopharyngeal carcinoma, EBV antibody (VCA-IgA) is often positive, etc. 4.Application of tumor markers Tumor markers are mainly used in the diagnosis and differential diagnosis of tumor and other diseases; to assist in the diagnosis of primary lesions and the primary site of unknown metastatic cancer; to monitor the treatment and prognosis of malignant tumors; the combined application of multiple tumor markers can improve the level of diagnosis and prognosis monitoring; and to apply to the screening of high-risk groups. 5.Superiority of tumor marker detection Because tumor markers can often be detected at the early stage of tumor or even before the tumor forms a mass, therefore, the detection of tumor markers in areas with high incidence of tumor or family history of tumor should be included in the scope of health checkup. If symptoms are found, tumor markers should be detected. 6.Limitations of tumor marker detection For people with family history and specific medical history, its early screening effect is better. However, since most tumor markers are not highly specific, they are more effective in prognosis and efficacy monitoring. The limitations of tumor marker testing are mainly reflected in the influencing factors: 1. the size of tumor and the number of tumor cells: the larger the tumor, the more cells, the higher the concentration of tumor markers. 2. 2. The speed of tumor cell synthesis and secretion of tumor markers: the faster the speed of tumor cell synthesis and secretion of tumor markers, the higher the concentration of tumor markers in blood circulation. 3.The blood supply of tumor tissue is good or bad: if the blood supply is poor, the concentration of tumor markers in blood circulation is low. 4.Whether there is necrosis of tumor cells and the degree of necrosis: after necrosis of tumor cells, a large amount of tumor markers will be released, which will increase the concentration of tumor markers in tumor local and blood. 5.The differentiation degree of tumor cells and the stage of tumor: the worse the differentiation degree of tumor cells, the more malignant they are and the more advanced they are, the more tumor markers they produce. 6.Whether tumor cells express and synthesize tumor markers: some tumor cells do not express or carry tumor markers, then they cannot be detected in blood and body fluids. 7.The degradation and excretion speed of tumor markers in body: If liver and kidney function is poor and excretion speed is slow, tumor markers can be abnormally elevated in body.