Carcinoembryonic antigen as a marker for colorectal cancer: Is it clinically useful?

Background: Carcinoembryonic antigen (CEA) is one of the most Widely used t umor markers worldwide. Its main application is mostly in gastrointestinal cancers, especially in colorectal malignancy. Although in use for almost 30 years, the clinical value of CEA in colorectal cancer is still not clear. Methods: The literature relevant to the clinical value of CEA in colorectal cancer was reviewed. Particular attention was paid to studies involving me taanalyses and guidelines issued by Expert Panels. Results: Although of little use in detecting early colorectal cancer, high preoperative concentrations of CEA correlate with adverse prognosis. Serial CEA measurements::can detect recurrent colorectal cancer with a sensitivit y of similar to 80%, a specificity of similar to 70%, and can provide a lea d time of similar to5 months. CEA is the most frequent indicator of recurre nce in asymptomatic patients and currently is the most cost-effective test for the preclinical detection of resectable disease. CEA is most useful for the early detection of liver metastasis in patients with diagnosed colorec tal cancer. Overall, however, little evidence is available that monitoring of all patients with diagnosed colorectal cancer leads to enhanced patient outcome or quality of life. Conclusions: Currently, the most useful application of CEA is in-the detect ion of liver metastasis from colorectal cancers. Because of the relative su ccess of surgery in resecting hepatic metastases, serial determinations of the:marker are recommended for detecting cancer spread to the liver. In the future, preoperative concentrations of CEA may be included with the standa rd staging procedures for assessing prognosis. (C) 2001 American Associatio n for Clinical Chemistry.