The elevation of tumor markers cannot be used as a criterion for tumor diagnosis alone, but its significance lies in the dynamic observation of its change pattern as a reference for determining the efficacy and monitoring the disease. 1.Cancer embryonic antigen (CEA): CEA is a glycoprotein embryonic antigen found in fetal and colon cancer tissues, which is a broad-spectrum tumor marker. The normal reference value of serum CEA is <5μg/L. The positive rate of CEA in malignant tumors is colon cancer (70%), gastric cancer (60%), pancreatic cancer (55%), lung cancer (50%), breast cancer (40%), ovarian cancer (30%), uterine cancer (30%) in order. CEA is an adhesion molecule and is an important marker of metastatic recurrence of many tumors. AFP is a glycoprotein synthesized by the liver and yolk sac during embryonic stage, and the level in normal adult blood circulation is very small <20μg/L. AFP is the best marker for the diagnosis of primary liver cancer, with a positive rate of 60%-70%. If serum AFP >400μg/L for 4 weeks or 200-400μg/L for 8 weeks, combined with imaging examination, the diagnosis of primary hepatocellular carcinoma can be made. AFP concentration in serum of patients with acute and chronic hepatitis and cirrhosis can be increased to different degrees, and its level is often <300ug/L. The level of AFP can be increased in reproductive embryonic tumors (testicular cancer, teratoma). The sensitivity of CA125 for ovarian epithelial cancer can reach about 70%. Other non-ovarian malignancies (cervical cancer, uterine body cancer, endometrial cancer, pancreatic cancer, lung cancer, gastric cancer, colon/rectal cancer, breast cancer) also have a certain positive rate. Benign gynecological diseases (pelvic inflammatory disease, ovarian cysts, etc.) and early pregnancy may show varying degrees of elevated serum CA125 levels. CA125 is an important tumor marker for monitoring the course of plasma ovarian cancer and the effect of treatment. The elevation of CA125 is more obvious in patients with ovarian cancer metastasis. After treatment, CA125 can be significantly decreased, if it cannot be restored to normal range, the possibility of residual tumor should be considered. 4.Glycan antigen 19-9 (CA19-9): the sensitivity of diagnosing pancreatic cancer is 82%. CA19-9 is a glycan antigen associated with gastrointestinal cancer, usually distributed in normal fetal pancreas, gallbladder, liver, intestine and normal adult pancreatic and bile duct epithelium. Testing patients' serum CA19-9 can be used as an auxiliary diagnostic indicator for pancreatic cancer, gallbladder cancer and other malignant tumors, and is of great significance in monitoring changes in disease and recurrence. Serum CA19-9 levels are also elevated to varying degrees in patients with gastric cancer, colon/rectal cancer, liver cancer, breast cancer, ovarian cancer, lung cancer, etc. Certain inflammatory diseases of the gastrointestinal tract also have different degrees of elevated CA19-9, such as: acute pancreatitis, cholecystitis, cholestatic cholangitis, hepatitis, cirrhosis, etc. 5.Cancer antigen 50 (CA50): CA50 is a marker of pancreatic and colon and rectal cancer, and is the most commonly used glycoantigen tumor marker, because it is widely present in the pancreas, gallbladder, liver, stomach, colorectum, bladder and uterus, and its tumor recognition spectrum is wider than CA19-9, so it is also a universal tumor marker-related antigen, rather than a tumor marker specific to an organ. CA50 can be detected in various malignant tumors with different positive rates. The positive detection rate for pancreatic cancer and gallbladder cancer is the first, accounting for 94.4%; the others are liver cancer (88%), ovarian and uterine cancer (88%) and malignant pleural fluid (80%) in order. It can be used for the early diagnosis of pancreatic cancer, gallbladder cancer and other tumors, and also has high value for the diagnosis of liver cancer, stomach cancer, colorectal cancer and ovarian cancer. 7.Glycan antigen 72-4 (CA72-4): CA72-4 is one of the best tumor markers for the diagnosis of gastric cancer, with high specificity and sensitivity up to 28-80%, if combined with CA19-9 and CEA, it can monitor more than 70% of gastric cancer. CA72-4 levels can rapidly decrease to normal after surgery. In 70% of recurrent cases, CA72-4 concentrations are first elevated. The main advantage of CA72-4 over other markers is its extremely high specificity for the differential diagnosis of benign lesions, with a detection rate of only 0.7% in a large number of patients with benign gastric disease. Colon/rectal cancer, pancreatic cancer, liver cancer, lung cancer, breast cancer and ovarian cancer also have a certain positive rate. 8.Glycolipid antigen 242 (CA242): CA242 is a glycolipid antigen associated with pancreatic cancer, gastric cancer and colorectal cancer, with elevated expression in gastric cancer, pancreatic cancer and colorectal cancer. Serum CA242 has good sensitivity (80%) and specificity (90%) for the adjuvant diagnosis of pancreatic cancer, colorectal cancer. Elevated serum CA242 levels are seen in patients with lung, liver and ovarian cancers. 9.Glycan antigen 15-3 (CA15-3): It can be used as an indicator for adjuvant diagnosis of breast cancer, postoperative follow-up and metastasis recurrence. It has low sensitivity (60%) for early stage breast cancer, 80% for late stage, and high positive rate (80%) for metastatic breast cancer. Other malignant tumors also have a certain positive rate, such as: lung cancer, colon cancer, pancreatic cancer, ovarian cancer, cervical cancer, primary liver cancer, etc. 10, Ferritin (SF): Elevated ferritin is seen in the following tumors: acute leukemia, Hodgkin's disease, lung cancer, colon cancer, liver cancer, and prostate cancer. Detection of ferritin has diagnostic value for metastatic tumors in the liver. 76% of patients with liver metastases have ferritin levels higher than 400 μg/L. When liver cancer is present, low AFP measurements can be supplemented with ferritin measurements to improve the diagnostic rate. Ferritin is also elevated in cases of hyperpigmentation, inflammation, and hepatitis. The elevation may be due to cell necrosis, blocked erythropoiesis or increased synthesis in tumor tissue. 11.Prostate specific antigen (PSA): It is the only recognized organ-specific tumor marker that can be used to monitor the disease progression and efficacy of prostate cancer, determine the prognosis, and can be used for screening of prostate cancer. The level of PSA in normal male serum is very low, with a serum reference value <4μg/L; PSA is organ-specific but not tumor-specific. The positive rate for the diagnosis of prostate cancer is 80%. Benign prostate disease is also seen with varying degrees of elevated serum PSA levels. Serum PSA measurement is a monitoring indicator for postoperative recurrence and metastasis of prostate cancer and for the observation of efficacy. It is present in the blood in two forms: bound PSA and free PSAF-PSA/T-PSA ratio is an effective indicator to differentiate prostate cancer from benign prostate disease. f-PSA/T-PSA>0.25 is mostly benign disease; f-PSA/T-PSA<0.16 is highly suggestive of prostate cancer. 12.β2-microglobulin (β2-MG) β2-microglobulin (β2-m): expressed on the surface of most nucleated cells. It is mostly used clinically to diagnose lymphoproliferative diseases, such as leukemia, lymphoma and multiple myeloma. Its level correlates with the number of tumor cells, growth rate, prognosis and disease activity. In addition, it can be used to stage patients with myeloma according to this level. Serum β2-MG can be increased in renal failure, inflammation and various diseases. Therefore, increased serum β2-MG should be excluded due to certain inflammatory diseases or reduced glomerular filtration function. 13.Squamous epithelial cell carcinoma antigen (SCCA): It is a tumor-associated antigen TA-4 extracted from cervical squamous epithelial cell carcinoma tissue, with a minimal serum content of <2.5 μg/L. SCCA is a tumor marker for squamous carcinoma, and is suitable for cervical cancer, squamous lung cancer, esophageal cancer, head and neck cancer, adjuvant diagnosis, treatment observation and recurrence monitoring of bladder cancer. 14.Neuron-specific enolase (NSE): NSE is an isoenzyme of enolase, which is a tumor marker for small cell lung cancer (SCLC) with a positive diagnostic rate of 91%. It helps in the differential diagnosis of small cell lung cancer and non-small cell lung cancer (NSCLC). It is also valuable for the observation of the efficacy and recurrence monitoring of small cell lung cancer. The serum NSE concentration can be significantly increased in neuroblastoma, neuroendocrine cell tumor. Cytokeratin 19 (Cyfra21-1): Cyfra21-1 is a soluble fragment of cytokeratin-19. Cyfra21-1 is a preferred marker for non-small cell lung cancer, especially squamous lung cancer. Cyfra21-1 is also a good marker for breast cancer, bladder cancer and ovarian cancer, and is a good adjuvant for diagnosis and treatment monitoring. 16.Nuclear Matrix Protein-22 (NMP-22): NMP-22 (NuclearMatrix Protein-22) is a component of the cytoskeleton. It is closely related to cellular DNA replication, RNA synthesis, gene expression regulation and hormone binding. In bladder cancer, a large number of tumor cells apoptosis and release NMP22 into urine, the urinary NMP22 can be increased 25?times. Using 10 kU/mL as the threshold value, the sensitivity for bladder cancer diagnosis is 70% and the specificity is 78.5%. The sensitivity for the diagnosis of invasive bladder cancer was 100%? 17.α-L-amyloidase (AFU): AFU is another sensitive and specific new marker for the detection of primary hepatocellular liver cancer. The serum AFU activity of primary hepatocellular carcinoma patients is significantly higher than that of other types of diseases (including benign and malignant tumors). However, it is worth mentioning that there is some overlap between serum AFU activity measurements in some metastatic liver cancer, lung cancer, breast cancer, ovarian or uterine cancer, and even in some non-neoplastic diseases such as cirrhosis, chronic hepatitis and gastrointestinal bleeding, which are also mildly elevated. The use of AFU should be measured simultaneously with AFP to improve the diagnosis of primary hepatocellular carcinoma, which has a better complementary effect.