Carcinoembryonic Antigen (CEA)

CPT Test code: 82378

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Related Information:	Cancer Antigen (CA) 15-3
Specimen:	Serum
Volume:	0.8 mL
Minimum Volume:	0.3 mL (Note: This volume does not allow for repeat testing.)
Container:	Red-top tube or gel-barrier tube
Special Instructions:	Values obtained with different assay methodologies should not be used interchangeably in serial testing. It is recommended that only one assay method be used consistently to monitor each patient’s course of therapy. This procedure does not provide serial monitoring; it is intended for one-time use only. If serial monitoring is required, please use the serial monitoring number 480095 to order.
Collection:	If a red-top tube is used, transfer separated serum to a plastic transport tube.
Storage Instructions:	Refrigerate
Causes for Rejection:	Citrate plasma specimen; improper labeling
Reference Interval:	Range: 0-4.7 ng/mL; nonsmoker: <3.9 ng/mL; smoker: <5.6 ng/mL
Use:	This assay is intended for the in vitro quantitative determination of carcinoembryonic antigen in human serum and plasma.¹ The Elecsys CEA assay is further indicated for serial measurement of CEA to aid in the management of cancer patients. The main indication for CEA determinations is the follow-up and therapy-management of colorectal carcinoma.
Limitations:	CEA determinations are not recommended for cancer screening in the general population. CEA concentrations within the normal range do not exclude the possible presence of a malignant disease. The measured CEA value of a patient’s sample can vary depending on the test procedure used. CEA values determined on patient samples by different test procedures cannot be directly compared with one another and could be the cause of erroneous medical interpretations. In patients receiving therapy with high biotin doses (ie, >5 mg/day), no sample should be taken until at least eight hours after the last biotin administration.¹ As with all tests containing monoclonal mouse antibodies, erroneous findings may be obtained from samples taken from patients who have been treated with monoclonal mouse antibodies or have received them for diagnostic purposes.¹ In rare cases, interference due to extremely high titers of antibody to streptavidin and ruthenium can occur. The test contains additives which minimize these effects.¹ For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination, and other findings.
Additional Information:	CEA is a monomeric glycoprotein (molecular weight approximately 180,000 daltons) with a variable carbohydrate component of approximately 45% to 60%.^1,2 CEA, like AFP, belongs to the group of carcinofetal antigens produced during the embryonic and fetal period. CEA is mainly found in the fetal gastrointestinal tract and in fetal serum. It also occurs in slight quantities in intestinal, pancreatic, and hepatic tissues of healthy adults. The formation of CEA is repressed after birth and, accordingly, serum CEA values are hardly measurable in healthy adults. High CEA concentrations are frequently found in cases of colorectal adenocarcinoma.^3,4 Slight to moderate CEA elevations (rarely >10 ng/mL) occur in 20% to 50% of benign diseases of the intestine, pancreas, liver, and lungs (eg, liver cirrhosis, chronic hepatitis, pancreatitis, ulcerative colitis, Crohn’s disease, emphysema).^3,5 Smokers also have elevated CEA values. The reactive epitopes of CEA have been characterized, and the available monoclonal antibodies classified, into six epitope groups.^6-8 The antibodies used in the Elecsys CEA assay react with epitopes two and five. The antibodies react with CEA and (as with almost all CEA methods) with the meconium antigen (NCA2).⁸ Cross-reactivity with NCA1 is 0.7%.
Footnotes:	1. CEA on Elecsys 1010/2010 and Modular Analytics E170, package insert 2007-08, V15, Indianapolis, IN: Roche Diagnostics, 2007. 2. Diamandis EP, Fritsche HA, Lilja H, et al. Tumor markers: Physiology, pathobiology, technology, and clinical applications. 1st ed. Washington, DC: AACC Press;2002. 3. Kuroki M, Haruno M, Arakawa F, et al. Reaction profiles of seven enzyme immunoassay kits for carcinoembryonic antigen (CEA) analyzed with purified preparations of CEA and related normal antigens. Clin Biochem. 1992; 25(1):29-35.PubMed 1551238 4. Sell SS. Serological cancer markers. Humana Press. 1992. ISBN 0-89603-209-4. 5. Stieber P, Fateh-Moghadam A. Sensible use of tumor markers. Boehringer Mannheim, Cat. N° 1536869 (Engl), 1320947 (German). ISBN 3-926725-07-9 German/English. Juergen Hartmann Verlag Marloffstein-Rathsberg (1993). 6. Thompson JA. Molecular cloning and expression of carcinoembryonic antigen gene family members. Tumor Biol. 1995; 16(1):10-16. PubMed 7863217 7. Hammarstrom S, Shively JE, Paxton RJ, et al. Antigenic sites In carcinoembryonic antigen. Cancer Res. 1989; 49(17):4852-4858.PubMed 2474375 8. Börmer OP, Thrane-Steen K. Epitope group specificity of six immunoassays for carcinoembryronic antigen. Tumor Biol. 1991; 12(1):9-15.PubMed 1705049
References:	Greiner JW, Guadagni F, Goldstein D, et al. Evidence for the elevation of serum carcinoembryonic antigen and tumor-associated glycoprotein-72 levels in patients administered interferons. Cancer Res. 1991; 51(16):4155-4163. PubMed 1907881 Kiang DT, Greenberg LJ, and Kennedy BJ. Tumor marker kinetics in the monitoring of breast cancer. Cancer. 1990; 65(2):193-199. PubMed 2295042 Kudo R, Sasano H, Koizumi M, et al. Immunohistochemical comparison of new monoclonal antibody 1C5 and carcinoembryonic antigen in the differential diagnosis of adenocarcinoma of the uterine cervix. Int J Gynecol Pathol. 1990; 9(4):325-336. PubMed 1700970 Norton JA. Carcinoembryonic antigen. New applications for an old marker. Ann Surg. 1991; 213(2):95-97. PubMed 1992947 Rocklin MS, Senagore AJ, Talbott TM. Role of carcinoembryonic antigen and liver function tests in the detection of recurrent colorectal carcinoma. Dis Colon Rectum. 1991; 34(9):794-797. PubMed 1914746 Tatsuta M, Iishi H, Ichii M, et al. Diagnosis of gastric cancers with fluorescein-labeled monoclonal antibodies to carcinoembryonic antigen. Lasers Surg Med. 1989; 9(4):422-426. PubMed 2503669 Theriault RL, Hortobagyi GN, Fritsche HA, et al. The role of serum CEA as a prognostic indicator in stage II and III breast cancer patients treated with adjuvant chemotherapy. Cancer. 1989; 63(5):828-835. PubMed 2914290 Torosian MH. The clinical usefulness and limitations of tumor markers. Surg Gynecol Obstet. 1988; 166(6):567-579 (review).PubMed 2453934