Carcinoembryonic Antigen (CEA), Serum

CPT CODE:

USEFUL FOR:

Monitoring colorectal cancer and selected other cancers such asmedullary thyroid carcinoma
May be useful in assessing the effectiveness of chemotherapy orradiation treatment
CEA levels are not useful in screening the general population for undetected cancers

SPECIMEN REQUIRED:

Draw blood in a plain, red-top tube(s) or a serum gel tube(s). Spin down and send 0.5 mL of serum refrigerated.  

TRANSPORT TEMPERATURE:

Refrig\Ambient <7 days OK\Frozen OK

CLINICAL INFORMATION:

CEA is a glycoprotein normally found in embryonic entodermal epithelium.
Increased levels may be found in patients with primary colorectalcancer or other malignancies including medullary thyroid carcinoma and breast, gastrointestinal tract, liver, lung, ovarian, pancreatic, and prostatic cancers.
Serial monitoring of CEA should begin prior to therapy to verify post therapy decrease in concentration and to establish a baseline for evaluating possible recurrence. Levels generally return to normal within 1 to 4 months after removal of cancerous tissue.

CLINICAL INTERPRETATION:

Grossly elevated CEA concentrations (>20 ng/mL) in a patient withcompatible symptoms are strongly suggestive of the presence ofcancer and also suggest metastasis.
Most healthy subjects (97%) have values < or =3.0 ng/mL.
After removal of a colorectal tumor, the serum CEA concentrationshould return to normal by 6 weeks, unless there is residual tumor.
Increases in test values over time in a patient with a history ofcancer suggest tumor recurrence.

REFERENCE VALUES:

Nonsmokers: < or =3.0 ng/mL

Some smokers may have elevated CEA, usually < or =5.0 ng/mL.

Serum markers are not specific for malignancy and values may

vary by method.