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Test ID: CEA Carcinoembryonic Antigen (CEA), Serum

Reporting Name

Carcinoembryonic Ag (CEA), S

Useful For

Monitoring colorectal cancer and selected other cancers such as medullary thyroid carcinoma


May be useful in assessing the effectiveness of chemotherapy or radiation treatment


This test is not useful for screening the general population for undetected cancers.

Clinical Information

Carcinoembryonic antigen (CEA) is a glycoprotein normally found in embryonic entodermal epithelium.


Increased levels may be found in patients with primary colorectal cancer 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.


Grossly elevated carcinoembryonic antigen (CEA) concentrations (>20 ng/mL) in a patient with compatible symptoms are strongly suggestive of the presence of cancer and suggest metastasis.


Most healthy subjects (97%) have values less than or equal to 3.0 ng/mL.


After removal of a colorectal tumor, the serum CEA concentration should return to normal by 6 weeks, unless there is residual tumor.


Increases in test values over time in a patient with a history of cancer suggest tumor recurrence.

Report Available

1 to 3 days

Day(s) Performed

Monday through Friday

Clinical Reference

1. Sturgeon C: Tumor markers. In: Rifai N, Horvath AR, Wittwer CT, eds: Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:436-478

2. Locker, GY, Hamilton S, Harris J, et al: ASCO 2006 update of recommendations for the use of tumor markers in gastrointestinal cancer. J Clin Oncol. 2006;24:5313-5327

3. Moertel CG, Fleming TR, Macdonald JS, et al: An evaluation of the carcinoembryonic antigen (CEA) test for monitoring patients with resected colon cancer. JAMA. 1993;270:943-947

Method Name

Immunoenzymatic Assay

Specimen Type


Specimen Required


Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.6 mL

Collection Instructions:

1. Serum gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged, and the serum aliquoted into a plastic vial within 2 hours of collection.

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 7 days
  Frozen  90 days

Reference Values

Nonsmokers: ≤3.0 ng/mL

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

Serum markers are not specific for malignancy, and values may vary by method.

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
CEA Carcinoembryonic Ag (CEA), S 83085-1


Result ID Test Result Name Result LOINC Value
CEA Carcinoembryonic Ag (CEA), S 83085-1


If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.

Mayo Clinic Laboratories | Endocrinology Catalog Additional Information:

mml-endo-thyroid, mml-adrenal-gonad-pituitary