1.Does a positive tumor marker mean that you have a tumor? Positive tumor markers do not necessarily mean that you are suffering from tumor. To confirm the diagnosis, further examination by CT, ultrasound and other methods are needed. At present, because 100% specific tumor markers have not been found, each tumor marker has certain false positives. The factors that cause false positives are: (1) Some diseases: inflammatory diseases can increase the expression of some tumor markers. AFP, CAl9-9, CEA in benign liver diseases and CAl5-3, CAl9-9, CEA and PSA levels in renal failure can be increased. (2) Physiological changes: AFP, CAl25, HGH and CAl25 are also elevated during pregnancy and menstruation. (3) During tumor surgery or radiotherapy/chemotherapy: certain tumor markers are increased due to the destruction of tumor tissues or tumor necrosis, thus affecting the determination of tumor markers and causing false positives. (4) Immunoglobulins in the sample can affect the measurement results by reacting with the specific antibodies used in the measurement. For example, patients with autoimmune diseases have a large amount of autoantibodies, such as rheumatoid factor (RF), which can react with tumor marker antibodies and form false positives, and heterophilic antibodies against animal immunoglobulins can also interfere with tumor marker assays and cause false positives, and the interfering indicators cover all items except PSA and f-PSA. (5) In addition, there are also interference from factors such as hemolysis and lipidemia of the sample, and false positives can occur when the subject has inflammation and poor health condition, and sometimes the test results even reach about two times of the critical value. 2.Does a positive tumor marker and other tests that do not detect cancer mean that there is no cancer for sure? In health checkups, some people often have positive tumor marker test results and then undergo various other tests but no cancer is found, how to explain? There are two cases, one is false positive as mentioned above and the other is true positive. Why can’t cancer be detected in other tests after a true positive result? There is a concept that needs to be clarified here. There are some cells in the human body that are cancerous every moment, but the immune system of the human body is at its own post to remove these cancerous cells every moment, maintaining a dynamic balance. Once the immunity of the human body is reduced and the ability of crippled cells to remove them is weakened, the number of cancer cells will gradually increase until a lump is formed, and that is when we call it cancer. It can be seen that cancer is a dynamic process and there are scattered cancer cells even when there is no lump. Scattered cancer cells or cancer lumps below 25px in diameter may not be detected by ultrasound, MRI, radiation and other examinations, but cancer cells are constantly secreting tumor markers, therefore, although cancer does not form a lump, tumor markers can be positive, and such positivity is true positive, but other examinations cannot be detected. Its value is that if we find a positive at this time, it should be very early and only if we take immediate measures to improve immunity, we can avoid the cancer and it may be negative at the next examination. There are follow-up observations that 99% of people with positive CEA in physical examination immediately did not find cancer by other methods, but 5% of them developed cancer within 3 to 5 years. Therefore, positive tumor markers still cannot be easily considered as false positives and should be given enough attention. 3.Does a negative tumor marker result mean that there is no cancer? Negative tumor marker result does not necessarily indicate that there is no tumor in the patient’s body. When the number of tumor cells producing tumor markers is small; the cells or cell surfaces are closed; some antibodies in body fluids form immune complexes with tumor markers (tumor antigens); the tumor tissues themselves have poor blood circulation and the tumor markers produced cannot be secreted into the peripheral blood, false negatives may also occur. If negative value is detected for patients with high suspicion or obvious symptoms, the influence of in vivo and in vitro factors of tumor marker determination should be considered, and re-measurement is recommended, combined with other examinations and specific analysis of specific conditions. 4.Is it not necessary to monitor tumor markers if tumor has been clearly diagnosed? The detection of tumor markers before, during and after tumor treatment can help to understand the effect of treatment. A better treatment effect can reduce the level of tumor markers, otherwise it means that the treatment effect is not good; the detection and research of tumor markers can also assist in the diagnosis of tumor staging in clinical practice, for example, the serum PAP of advanced prostate cancer patients is significantly higher than that of early stage patients, and the detection of serum PAP level can assist in the diagnosis of tumor staging. For example, the serum PAP level of prostate cancer is significantly higher than that of early stage patients. The higher the level, the worse the prognosis. Therefore, even if a tumor has been clearly diagnosed, to a certain extent, tumor markers still need to be detected. 5.Do I still need to monitor tumor markers frequently after the tumor is cured? Tumor markers can monitor whether there is early recurrence and metastasis of tumor. Regular testing of relevant tumor marker content for tumor patients after treatment can detect recurrence and metastasis of tumor at an early stage, such as CEA for colorectal cancer and HCG for choriocarcinoma. 6.Is cancer an incurable disease? For a long time, people think that cancer is an incurable disease and once cancer is diagnosed, death is certain. Such concept and impression make people fear cancer and avoid “cancer” and “medical treatment”, so they do not go to hospitals for treatment and delay the treatment time. The progress of modern medicine shows that many cancers are not incurable. Many common malignant tumors such as breast cancer, lung cancer, liver cancer and gastrointestinal malignant tumors can be detected early and removed by radical surgery, and the survival period can reach l0-30 years. Even for some malignant tumors that have lost the chance of surgical treatment, the survival period can be significantly extended and the quality of life greatly improved by chemotherapy, radiotherapy, interventional therapy, immunotherapy and Chinese medicine.