In recent years, the incidence of malignant tumors has been increasing year by year and the trend of youthfulness. It is understood that the main reason why the treatment effect of common malignant tumors is unsatisfactory is that patients often have missed the best period of disease treatment when they come to the hospital. The key to cure malignant tumors is early detection and early treatment. Therefore, it is especially important to have regular medical checkups every year. Many people will choose tumor marker test during physical examination. First of all, we need to understand what are tumor markers? Tumor Marker is a chemical substance that reflects the presence of tumor. They are either not found in normal adult tissues but only in embryonic tissues, or their content in tumor tissues is much higher than that in normal tissues. Their existence or quantitative changes can suggest the nature of tumor, so as to understand the histogenesis, cell differentiation and cell function of tumor, which can help diagnosis, classification, prognosis judgment and treatment guidance of tumor. These substances can be found in the tissues, body fluids and excreta of tumor patients and can be detected by immunological, biological and chemical methods. AFP: The content of AFP in adult serum is usually very low, with a reference value of <20μg< span="">/L. Significantly elevated AFP is seen in:? Primary liver cancer, 68.8% of patients with elevated AFP, often >300μg/L;? Viral hepatitis and cirrhosis, patients can have varying degrees of increased AFP in the serum, usually below 300μg/L;? Reproductive system tumors and embryonic tumors, such as testicular cancer, teratoma, etc.; {C} ④ {C} pregnancy. 2, carcinoembryonic antigen (CEA): under normal circumstances, serum CEA <5.0μg< span="">/L. Elevated serum CEA is mainly seen in:? colon cancer, rectal cancer, pancreatic cancer, lung cancer, breast cancer, gastric cancer, and metastatic liver cancer;? intestinal polyps, diverticulitis, colitis, cirrhosis, hepatitis, pancreatitis and lung disease;? About 33% of smokers have CEA>5μg/L. 3.CA125: very important ovarian cancer-related antigen, reference value: serum <35kU/L. Elevated serum CA125 is mainly seen in:? Ovarian cancer, with a positive rate of about 61.4%. If surgery and chemotherapy are effective, CA125 level decreases quickly. In case of recurrence, CA125 elevation may precede the appearance of clinical symptoms. Therefore, CA125 is a good indicator to observe the efficacy of treatment and determine whether there is recurrence;? Other non-ovarian malignant tumors also have a certain positive rate, such as breast cancer 40%, pancreatic cancer 50%, gastric cancer 47%, lung cancer 41.4%, colorectal cancer 34.2%, other gynecological tumors 43%;? Non-malignant tumors, such as endometriosis, pelvic inflammatory disease, ovarian cysts, pancreatitis, hepatitis, liver cirrhosis, etc.; ④ In early pregnancy, CA125 is elevated. 4.CA153: breast cancer related antigen, reference value: serum <28kU/L. Elevated serum CA15-3 is mainly seen in:? Breast cancer, but the early positive rate is low about 30%, and the positive rate of metastatic breast cancer can reach 80%.? Other malignancies, such as lung, colon, pancreatic, ovarian, cervical, and primary liver cancers.? Non-malignant tumor diseases such as liver, gastrointestinal tract, lung, breast, ovary, etc., the positive rate is generally less than 10%. 5.CA199: gastrointestinal cancer-related antigen, the content in normal human tissues is very small, the reference value is <37kU/L. Elevated serum CA125 is mainly seen in: ? Pancreatic cancer, gallbladder cancer, bile duct pot belly cancer, serum CA19-9 level is significantly increased, the positivity rate is about 74.9%, especially in advanced pancreatic cancer patients, serum CA19-9 concentration can reach 400,000kU/L;? The positive rate of gastric cancer is about 50%, and the positive rate of colon cancer is about 60%;? Acute pancreatitis, cholecystitis, cholestatic cholangitis, liver cirrhosis, hepatitis and other diseases, CA19-9 also has different degrees of elevation. 6.CA50: Reference value: serum <20 μg/L. CA50 is similar to CA199 and can be used to monitor progressive gastrointestinal and pancreatic cancer, but the specificity is poorer than CAl99. 7. Prostate-specific antigen (PSA): minimal in normal human serum, reference values: serum t-PSA (total PSA) <4.0 μg< span="">/L, f-PSA (free PSA) <0.8 μg< span="">/L, f-PSA/t-PSA >25%. Elevated serum PSA is mainly seen in: prostate cancer, prostate hypertrophy, prostatitis and urogenital diseases. 8, human chorionic gonadotropin (hCG): normal serum reference value: <5 IU/L. Elevated serum hCG is mainly seen in: ? Trophoblastic tumors and germ cell tumors, such as staphyloma, chorionic cell carcinoma, spermatogonial cell testicular cancer, etc. Chorionic cell carcinoma hCG is 100% elevated and can be as high as 1 million IU/L;? Other malignant tumors, such as breast cancer, gastrointestinal tract cancer, lung cancer, pancreatic cancer, etc. can also be seen to be elevated, but the magnitude of elevation is low;? Benign diseases, such as ovarian cysts, endometriosis, liver cirrhosis, etc., can also be seen elevated. 9. Neuron-specific enolase (NSE): normal reference value: serum <15ug/L. ①It is considered the preferred marker for detecting small cell lung cancer. 60%-80% of small cell lung cancer patients have elevated NSE. In remission, 80%-96% of patients have normal NSE levels. If NSE is elevated, it suggests recurrence. ~12 weeks. ②It can be used to monitor changes in neuroblastoma, evaluate the efficacy and predict recurrence. ③Serum NSE can also be increased in endocrine tumors, such as pheochromocytoma, islet cell tumor, medullary thyroid carcinoma, melanoma, retinoblastoma, etc. CY211: normal reference value: serum <3.3ug/L. It is mainly from epithelial cells and can be detected in 65% of lung cancers, 60% of colorectal cancers and 38.5% of pancreaticobiliary duct cancers, CY211 level is related to the type and clinical stage of lung cancer. The levels for different stages of lung cancer were in the order of I<< span="">II<< span="">III<< span="">IV. In the case of surgical resection without extensive metastasis, serum CY211 can be reduced to normal within 3-5 weeks, and can also be reduced to varying degrees in those with effective chemotherapy due to shrinkage or absorption of the lesion. On the contrary, if the tumor growth is not controlled or continues to grow, it will not be reduced if chemotherapy is ineffective. 11.Squamous cell carcinoma antigen (SCCA): normal reference value: serum <2ug/L. SCCA is a marker of squamous epithelial carcinoma, and SCCA is elevated in all kinds of squamous carcinoma. The positive rate of lung squamous carcinoma is 46-90%, and the concentration of SCCA in serum increases with the aggravation of the disease. 12.Tissue polypeptide antigen (TPA): normal reference value: serum <120 U/L. TPA mainly exists in placenta and most tumor tissues, and the detection rate of serum TPA in patients with various malignant tumors (ovarian cancer, colon cancer, rectal cancer, hepatocellular carcinoma, pancreatic cancer, lung cancer, breast cancer, endometrial cancer, testicular tumor, etc.) (>130 U/L serum is positive) can range from 20% to 90%. The presence of TPA does not correlate with tumor site and tissue type. Misconceptions about tumor markers 1. Do tumor marker tests help in the early diagnosis of tumor? In fact, except for AFP, PSA, F-PSA and their ratios, which can help the early diagnosis of primary liver cancer and prostate cancer, other tumor markers are not of great significance for the early diagnosis of tumor, and their clinical value is mainly reflected in the analysis of efficacy, prognosis and prediction of recurrence and metastasis. The early diagnosis of tumor needs to be combined with medical history, symptoms, physical signs, imaging examination (ultrasound, CT, X-ray, gastroscopy, colonoscopy), etc., and the definite diagnosis needs to rely on pathological examination. 2.Can negative tumor markers exclude related tumors? Since most of the tumor markers are not significant for the early diagnosis of tumor, the negative tumor markers cannot completely exclude the related tumor. Even for tumor markers like AFP, which is quite significant for the early diagnosis of primary liver cancer, its positive rate only reaches 79%-90% (the positive threshold for AFP to diagnose primary liver cancer is >400ng/ml). In other words, there are still 10%~30% of patients with primary liver cancer, AFP is normal or only mildly elevated. 3.Can abnormal tumor markers diagnose related tumors? Many benign diseases can have abnormal tumor markers, for example, prostate hypertrophy and prostatitis can have mild to moderate elevation of PSA, endometriosis can have mild to moderate elevation of CA125, and acute and chronic liver diseases can have different degrees of elevation of CA125, CA199, CA50 and ferritin. Biliary tract disease with jaundice often has a significant increase in CA199 and CA50, and even long-term smokers may have a mild increase in CEA. 4, what is the value of mild elevation of tumor markers? Because many benign diseases can have abnormal tumor markers, some people think that a mild elevation of tumor markers is of little value, and it is only meaningful if it is more than 5 times the normal reference value. This is not true because in most cases, the range of normal reference values is set relatively wide. Therefore, after excluding benign diseases, even a mild elevation of tumor markers is also of great value. How to make better use of tumor markers Those who have family history of tumor or clinical suspicious symptoms should be tested for tumor markers as soon as possible. For example, the preferred tumor markers for lung cancer are CEA, NSE and CY211, and the supplementary tumor markers are SCCA and TPA, as well as adrenocorticotropic hormone (ACTH) and calcitonin; for liver cancer, the preferred tumor marker is AFP, and the supplementary tumor marker is CEA, as well as alkaline phosphatase (ALP), r-glutamyl transferase (r-GT), etc. Glutamyl transferase (GGT), etc. For those who have positive initial tumor markers without any abnormalities, it is recommended to review the test periodically. If the result is negative, it may be a transient elevation caused by benign diseases. If the test is negative, it may be a transient elevation due to benign disease. If the test is consistently positive for three consecutive times, it should be taken seriously with detailed medical history, physical examination and imaging. If the tumor marker is persistently positive and no positive sign is detected for a while, it is recommended to continue to follow up regularly. The application of tumor markers lies in dynamic observation, rational application and joint testing, which is more beneficial to the prevention and treatment of tumor. V. Conclusion With the development of medical technology, more and more tumor markers will be discovered. Above we have only listed several common tumor markers to help you understand tumor markers correctly, and to draw in the jade, how to better use tumor markers to diagnose tumor and detect the development of disease still needs the guidance of professional doctors.