Tumor markers are substances that are synthesized or released by tumor cells or produced by the body in response to tumor cells during the process of tumor development. When tumors occur in the body, certain tumor markers in the body may increase accordingly. Therefore, it is convenient and fast to detect abnormally elevated tumor marker levels in the blood, which can help detect tumors early before symptoms appear. Some of these tumor markers are now used as screening tests in population health checkups. The significance of checking tumor markers is: 1. Early screening of tumor. A good tumor marker has some general significance in the screening of tumor. For example, chorionic gonadotropin (HCG) has been successfully used to screen for choriocarcinoma in the general population, and the use of this marker for screening has resulted in a significant decrease in mortality of choriocarcinoma patients worldwide. Since its introduction, fetal alpha globulin (AFP) has been of greater practical value in screening for hepatocellular carcinoma in the hepatitis B patient population. There are few patients with early stage pancreatic cancer, prostate cancer, gastrointestinal tract cancer, etc. detected by tumor marker elevation in clinical work follow-up. Therefore, the screening of tumor markers has great application value for high-risk groups. 2.Differential diagnosis after the appearance of tumor symptoms or suspicious masses. When patients are suspected to have tumors, the detection of tumor markers is helpful to identify whether they are benign and malignant tumors. 3.The judgment of biological characteristics and disease stage. Once the diagnosis is clear, the basal level of tumor markers should be measured in order to provide help in estimating the prognosis. 4.Efficacy observation and judgment of prognosis. It is the most valuable role of tumor markers. Tumor markers increase before surgery and decrease after surgery, indicating successful surgery; decrease after surgery and increase significantly after some time, suggesting tumor recurrence or metastasis. This indication often precedes the appearance of clinical symptoms by several months. After treatment, the rise and fall of tumor markers correlate well with patient outcome and prognosis. Tumor markers decrease after treatment indicates that the treatment is effective; if tumor markers continue to increase after treatment, the treatment plan should be replaced. If tumor markers continue to increase after replacing the treatment plan, it often indicates recurrence or metastasis. 5. Combined detection of multiple tumor markers can improve the sensitivity of diagnosis. The occurrence of tumor is a multi-step and multi-gene cancer process. It is manifested as the difference of different tumor pathological types after carcinogenesis and the difference between tumor cells of the same pathological type. There are cells with different characteristics in one tumor, so the same tumor may contain one or more tumor markers, while different tumors or different tissue types of the same tumor may also have common or different tumor markers. The combination of selected specific tumor markers can improve the positive rate of tumor marker testing. It should be reminded that rapid cancer tests are still extremely cutting-edge and cutting-edge research, and very few of them can really be used in clinical practice. Most of the known tumor markers belong to tumor-related antigens, but few of them are really tumor-specific antigens, and the era of real tumor markers has not yet arrived. “One drop of blood is not credible to detect cancer. It takes at least two to three milliliters of blood to detect tumor. The tumor screening should be selected. Health checkups must be based on the characteristics of each person to select the relevant tumor screening. Although more and more people take part in health checkups think that “cost is not a problem, what is important is to find out the problem”, medical personnel should focus on the scientificity of the test method and selectively apply it to the most suitable people for some new checkups, rather than being superficially advertised. The medical professionals should focus on the scientific method and selective application of the test for the most suitable people, rather than being confused by the superficial propaganda of “being able to quickly detect how many tumors”. Early detection of cancer is complicated. When there is an abnormal tumor marker test, it does not mean that the test subject will get cancer. This is mainly because the abnormality of a marker is affected by many factors, and the test method itself and the sample size will affect the accuracy of the results. Therefore, to confirm the diagnosis of cancer, an oncologist needs to combine the patient’s medical history, family history, symptoms and signs and other test results before making a conclusion.