What Is Antigen Detection?
Carcinoembryonic antigen (CEA) is a tumor-associated antigen first extracted from colon cancer and embryonic tissues by Gold and Freedman in 1965. It is an acidic glycoprotein with the characteristics of human embryonic antigens and is found in endoderm cells. The surface of differentiated cancer cells is a structural protein of the cell membrane. It is formed in the cytoplasm, is secreted extracellularly through the cell membrane, and then enters the surrounding body fluids. Therefore, it can be detected from serum, cerebrospinal fluid, breast milk, gastric juice, pleural and ascites fluid, urine, and feces.
Basic Information
- Chinese name
- Carcinoembryonic antigen
- Foreign name
- carcinoembryonic antigen
- nickname
- CEA
- Meaning
- Auxiliary diagnostic indicators for gastrointestinal tumors
Clinical significance of carcinoembryonic antigen
- CEA elevations are common in colorectal cancer, pancreatic cancer, gastric cancer, breast cancer, medullary thyroid cancer, liver cancer, lung cancer, ovarian cancer, and urinary tumors. But smoking, pregnancy and cardiovascular disease, diabetes, intestinal diverticulitis, rectal polyps, colitis, pancreatitis, cirrhosis, hepatitis, lung diseases, etc., 15% to 53% of patients with serum CEA will also increase, Therefore, CEA is not a specific marker of malignant tumors, and has only auxiliary value in diagnosis.
- In addition, the level of carcinoembryonic antigen is related to the following factors: It is related to the early, middle, and advanced stages of cancer. The value of carcinoembryonic antigen increases as the stage progresses, but the positive rate is not very high. It is related to tumor metastasis. After metastasis, the concentration of carcinoembryonic antigen also increases. It is related to the tissue type of cancer. Adenocarcinoma is the most sensitive, followed by squamous cell carcinoma and poorly differentiated carcinoma. This indicates that carcinoembryonic antigen is a differentiated antigen, and the higher the degree of differentiation, the higher the positive rate. It is related to the improvement of the condition. The serum carcinoembryonic antigen concentration decreases when the condition improves, and increases when the condition worsens. Continuous follow-up detection of carcinoembryonic antigen can be used to observe the curative effect and prognosis of malignant tumors after surgery, and can also be used to observe the curative effect of chemotherapy patients.
Reference range of normal carcinoembryonic antigen
- <5.0ng / ml