In the face of the increasing incidence of tumor, people’s concern about health and the convenience of various tests, many people only rely on “tumor marker test” to determine whether they are suffering from tumor. Many people only rely on “tumor marker test” to determine whether they are suffering from tumor or not. The reliability is very low. However, these tumor markers do not correspond with tumors one by one, so we should not simply think that a high indicator means tumor, and a normal indicator means everything is fine. To put it simply: most tumor patients will have abnormal tumor markers, but there are also many tumor patients, these indicators are normal. And there are also some normal people who have abnormal indicators, while in fact they do not have tumor, but may be due to some benign diseases, there is a great heterogeneity and individual difference in this. What exactly are tumor markers? TumorMarkers are chemical substances that reflect the presence of tumors. They are either not found in normal adult tissues but only in embryonic tissues, or their content in tumor tissues greatly exceeds the content in normal tissues. As one of the tumor markers, the level of carcinoembryonic antigen CEA is increased in malignant tumors such as colorectal cancer, lung cancer, gastric cancer, breast cancer, etc., and the change is parallel to the tumor growth and decline. For patients who have been diagnosed with cancer, testing “tumor markers” can evaluate the disease and determine the efficacy of treatment. After cancer surgery, if tumor recurrence occurs, CT and MRI may not detect it within a certain time window, but tumor markers will gradually increase, so that doctors can judge the condition and intervene in advance. In addition, some tumor patients’ tumor markers do not increase from the beginning to the end, so the value of tumor markers should not be overly valued, and caution is the right attitude. Therefore, if the tumor marker is slightly elevated, it is recommended to review the abnormal items to exclude the errors caused by reagents, testing methods, personnel or machine errors. This situation is more common. If the marker is elevated, false positive must be ruled out first, and it should not be ignored, and in order to completely rule out the possibility of early stage cancer, it needs to go to hospital for retesting. If the elevation is persistent, we should suspect that cancer is developing. If a cancer patient finds that the marker is significantly higher after surgery than before surgery, the possibility of recurrence should be considered, and the doctor should be asked to interpret it and do further examination to determine whether it is a recurrence. What should be done if tumor markers are found to be increased in physical examination? 1. It is recommended to review the abnormal items to exclude the errors caused by reagents, testing methods, personnel or machine errors. This is a common situation, and false positive must be ruled out first, so as not to diagnose “cancer” by yourself; 2. What is the degree of increase? Some benign diseases are often accompanied by mild increase of tumor markers, how to determine “no cancer” is not recommended to check the internet and make your own conclusion, but to seek consultation, analysis and examination from experienced doctors in oncology.