A class of biochemical substances produced by tumor tissue itself, which can reflect the existence and growth of tumor. There are mainly embryonic antigens, glycoantigens, natural autoantigens, cytokeratins, tumor-related enzymes, hormones and certain oncogenes. 1) Tumor markers are produced by tumor tissues, including: differentiation antigens; embryonic antigens (AFP, CEA); isoenzymes (NSE); hormones (HCG); tissue-specific antigens (PSA, free PSA); mucins, glycoproteins, glycolipids (CA125); oncogenes and their products; polyamines, etc. 2) produced by tumor-host interaction, including: serum ferritin; immune complexes; acute phase isoenzymes; interleukin receptors; tumor necrosis factor, etc. Overview of the glycoantigen system In the 1980s, experts obtained tumor-specific macromolecular glycoprotein antigens (carbohydrate antigen, CA) using hybridoma technology, and developed a monoclonal antibody recognition system. CA is a relevant antigen for tumor cells. The commonly used CA series are: CA 125 (ovarian cancer related antigen); CA 19-9 (pancreatic and biliary tract cancer related antigen); CA 15-3 (breast cancer related antigen); CA72-4 (gastric cancer related antigen). II. Application of tumor markers 1) application of tumor screening and screening programs; 2) diagnosis and differential diagnosis of tumors; 3) judgment of efficacy and prognosis; 4) determination of biological characteristics and disease stages; 5) monitoring of surgery, chemotherapy and radiotherapy; 6) determination of primary tumors of metastases of unknown origin; 7) combined application of multiple tumor markers to improve detection efficiency; III. Tumors: hepatocellular carcinoma and germ cell carcinoma. Other related tumors: embryonal cell carcinoma, ovarian teratoma, gastric cancer, biliary tract cancer, pancreatic cancer, etc. Other influencing factors: benign diseases including hepatitis, cirrhosis, enteritis, and hereditary tyrosinemia may be elevated; pregnancy may also increase temporarily. 2. CEA Mainly related tumors: broad-spectrum tumor marker. Other related tumors: common in lung cancer, colorectal cancer, pancreatic cancer, gastric cancer, breast cancer, medullary thyroid cancer, etc. Other influencing factors: Smokers have more false positives, and serum CEA is also elevated in about 15~53% of women in pregnancy and patients with cardiovascular disease, diabetes, non-specific colitis, etc. 3. CA242 Mainly related tumors: pancreatic cancer, stomach and colon cancer. Other related tumors: liver cancer, esophageal cancer, lung cancer. Other influencing factors: benign gastrointestinal diseases such as pancreatic cancer, hepatitis and cirrhosis of the liver will be elevated in patients. 4. CA125 starred in related tumors: ovarian cancer. Other related tumors: lung cancer, pancreatic cancer, breast cancer, liver cancer, gastrointestinal malignant tumors, uterine cancer. Other influencing factors: female pelvic inflammatory disease, endometriosis, menstruation, ovarian cysts, uterine fibroids, chronic hepatitis, pancreatitis, cholecystitis, pneumonia, etc. will be elevated. 5. CA199 is mainly related to pancreatic cancer, bile duct cancer and colorectal cancer. Other related tumors: liver cancer, gallbladder cancer, bile duct cancer, etc. Other influencing factors: many patients with benign diseases of the digestive system are also elevated, and nearly 10% of patients with pancreatitis are reported to have moderately elevated serum CA19-9. 6. CA153 Mainly related tumors: the preferred marker for breast cancer. Other related tumors: lung cancer, ovarian cancer, lung adenocarcinoma, colorectal cancer, etc. can be increased. Other influencing factors: serum CA15-3 of patients with benign breast disorders, endometriosis, ovarian cysts, etc. may also exceed the normal value. 7. CA724 Mainly related tumor: one of the best tumor markers for gastric cancer. Other related tumors: It also has different detection rates for other gastrointestinal cancers, breast cancer, lung cancer, ovarian cancer, etc. Other influencing factors: benign diseases have less effect on CA72-4. 8. CA50 Mainly related tumors: Marker for pancreatic and colon and rectal cancers. Other related tumors: gastric cancer, gallbladder cancer, liver cancer, lung cancer, breast cancer. Other influencing factors: CA50 will also be elevated at the onset of atrophic gastritis, pancreatitis, colitis and pneumonia. 9. NSE Mainly related tumors: small cell lung cancer. Other related tumors: adenocarcinoma of the lung, large cell lung cancer, and cancer of the nervous system. Other influencing factors: If hemolysis occurs or if there is prolonged stagnation time after blood collection in separating plasma serum or improper centrifugation to destroy cells, it can lead to elevated NSE. 10. CYFRA21-1 Mainly related tumors: squamous lung cancer, cervical cancer, esophageal cancer. Other related tumors: bladder cancer, nasopharyngeal carcinoma, ovarian cancer, gastrointestinal tract cancer. Other influencing factors: hepatitis, pancreatitis, pneumonia, prostate enlargement may also be elevated. 11. f-PSA Mainly related tumors: prostate cancer. Other related tumors: certain gynecological tumors and breast cancer. Other influencing factors: prostate enlargement can cause elevation. 12. t-PSA Mainly related tumor: prostate cancer. Other related tumors: certain gynecological tumors, polycystic ovary syndrome, breast cancer. Other influencing factors: prostatitis and prostate enlargement may cause elevation. 13. Free β-hCG is mainly associated with gynecological tumors and non-seminogenic testicular cancer. Other related tumors: breast cancer, spermatogenic testicular cancer, lung cancer, liver cancer, etc. Other influencing factors: Free β-hCG level may increase when suffering from endometriosis, ovarian cysts and other non-tumor states, pneumonia and prostate enlargement. 14.SCCA is mainly related to tumor: cervical squamous carcinoma. Other related tumors: squamous lung cancer, head and neck squamous cancer, esophageal cancer and vulvar squamous cell carcinoma, etc. Other influencing factors: SCCA values are increased in patients with hepatitis, cirrhosis, pneumonia and tuberculosis. 15. β2-MG Mainly related tumors: Adjuvant markers of malignant tumors, especially in chronic lymphocytic leukemia, lymphocytic sarcoma, multiple myeloma, etc. Other related tumors: elevated in lung cancer, breast cancer, gastrointestinal tract cancer and cervical cancer. Other influencing factors: It can be increased in renal failure, various hematologic diseases and inflammation, and it can be increased in various diseases, so we should exclude the increase of serum β2-MG due to some inflammatory diseases or glomerular filtration function bottoming out.