Carcinoembryonic antigen or CEA is a protein produced early in fetal life and during the rapid multiplication of cells in the digestive system, mainly, and can then be used as a marker of colorectal cancer. However, people without any gastrointestinal abnormalities or smokers may have increased concentrations of this protein, therefore it is necessary to perform other tests to confirm the diagnosis of the tumor.
The carcinoembryonic exam is more used to monitor the patient undergoing treatment for colorectal cancer, with normalization of the concentration of this protein being observed after about 6 weeks after surgery, for example. This protein may also be increased in people who have changes in the pancreas, liver and even the breast, being indicative of breast dysplasia. Learn more about breast dysplasia.
Reference values
The reference value for the carcinoembryonic examination varies according to the laboratory, so it is recommended that the dosage of the antigen is always done in the same laboratory to allow a more accurate interpretation of the examination and the patient's clinical condition. The reference values are usually:
- In smokers: up to 5.0 ng / mL; In non-smokers: up to 3.0 ng / mL.
The concentration in the blood may be slightly increased in people without any malignant change, for example, however, when the value is 5 times higher than the reference value, it may be indicative of cancer with possible metastasis. Therefore, it is important to measure and evaluate other tumor markers, in addition to the complete blood count and biochemical tests for the diagnosis to be completed. Find out which tests detect cancer.
What is it for
The carcinoembryonic antigen is usually requested to assist in the diagnosis of colorectal cancer. However, due to its low specificity, other tests are necessary to confirm the diagnosis, the CEA being more used to monitor the patient after the operation and verify the response to chemotherapy, for example. Know the symptoms of bowel cancer.
In addition to being indicative of gastrointestinal cancer, it can also have its concentration increased in other situations, such as:
- Pancreatic cancer; Lung cancer; Liver cancer; Inflammatory bowel disease; Thyroid cancer; Pancreatitis; Lung infections; Smokers; Benign breast disease, which is characterized by the presence of benign nodules or cysts in the breast.
Due to the various situations in which the carcinoembryonic can be elevated, it is recommended that other tests be performed so that the diagnosis can be made correctly.
