Carcinoembryonic Antigen (CEA) Test

The Carcinoembryonic antigen (CEA) test is a blood test used to measure the level of CEA, a protein that may be found in the blood when certain types of cancer are present.

What is CEA?

Carcinoembryonic antigen (CEA) is a type of glycoprotein that is normally produced by cells in the fetus during embryonic development. In adults, CEA levels are usually very low or undetectable. However, in some types of cancer, such as colorectal, lung, breast, and pancreatic cancer, CEA levels may be elevated.

How is the test performed?

The CEA test is a simple blood test that requires a sample of blood to be drawn from a vein in the arm. The blood sample is then sent to a laboratory for analysis, where the level of CEA is measured using an immunoassay technique.

What are the uses of the CEA test?

The CEA test has several uses:

• Monitoring cancer treatment: The CEA test can be used to monitor the effectiveness of cancer treatment, such as chemotherapy or surgery. A decrease in CEA levels may indicate that the treatment is working.
• Detecting cancer recurrence: The CEA test can also be used to detect cancer recurrence in patients who have been previously treated for cancer. Elevated CEA levels may indicate that the cancer has returned.
• Diagnosing cancer: While the CEA test is not typically used as a screening test for cancer, it may be used in conjunction with other tests to help diagnose certain types of cancer, such as colorectal or lung cancer.

Interpretation of results

The interpretation of CEA test results depends on the individual's medical history and the type of cancer being monitored. In general:

• Normal levels: CEA levels are usually considered normal if they are less than 5 ng/mL.
• Elevated levels: Elevated CEA levels may indicate the presence of cancer, but can also be caused by other factors, such as smoking or liver disease.
• Increasing levels: Increasing CEA levels over time may indicate that a cancer is growing or spreading.
• Decreasing levels: Decreasing CEA levels over time may indicate that a cancer treatment is effective.

Limitations of the test

The CEA test has several limitations:

• Lack of specificity: Elevated CEA levels can be caused by non-cancerous conditions, such as liver disease or smoking.
• Lack of sensitivity: Not all types of cancer produce elevated CEA levels, and some cancers may not be detected by the test.
• False positives and false negatives: The test can produce false positive or false negative results, which can lead to unnecessary anxiety or delayed diagnosis.

Conclusion

The Carcinoembryonic antigen (CEA) test is a useful tool for monitoring cancer treatment and detecting cancer recurrence. However, it has limitations and should be used in conjunction with other diagnostic tests and medical evaluations to ensure accurate results.