Generally speaking, low tumor marker does not have any substantial clinical significance and is a relatively normal situation, while low tumor marker after treatment indicates that the disease has been basically controlled, and the specific situation varies from person to person. Tumor markers refer to the substances that characteristically exist in malignant tumor cells and are produced as a result of tumor stimulation, mainly including embryonic antigens, glycan antigens, and hormonal substances, such as alpha-fetoprotein, glycan antigen 125, and human chorionic gonadotropin, etc. Each tumor marker has its own clinical significance. Each tumor marker has its own range of normal values and is not easily influenced by other factors. If the tumor marker is low, below normal, then it is a normal situation, and has no substantial clinical significance. If the tumor marker index becomes lower after a period of treatment, it means that the treatment has produced certain effect and the cancer cells have basically been controlled. However, it should be noted that the elevation of tumor markers does not necessarily mean that there is cancer, and it may be related to the inflammatory response, so the patient should strictly follow the doctor’s arrangement, combined with other tests, such as imaging tests, pathology tests, etc., to confirm the diagnosis of the disease.