Tumor marker tests are only for clinical reference only and cannot be relied upon alone to confirm a tumor diagnosis. Tumor markers can be enzymes, hormones, glycoproteins, embryonic antigens or tumor metabolites. Most tumor markers rise in both malignant tumors and benign lesions, so the specificity is poor. However, they can be used as auxiliary diagnosis, and have certain value in determining the efficacy and follow-up. Tumor marker test can be used as an auxiliary diagnosis, and it is not certain that you have a malignant tumor when it is elevated. Carcinoembryonic antigen is a group of glycoproteins produced by gastrointestinal tract, which can be increased in colon cancer, lung cancer and breast cancer; the detection of carcinoembryonic antigen after colorectal cancer surgery can predict recurrence. Alpha-fetoprotein is used for liver cancer screening in China with good results, but it is also elevated in pregnant women and patients with active hepatitis. Tumor marker test can only be used as a reference, if you find your tumor marker value is elevated during physical examination, you can review it, if it is elevated for many times in a row, you should pay attention to it, and perform a whole body examination if necessary.