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CARCINOEMBRYONIC ANTIGEN (CEA)

Item Value
Available Stat? No
Test code CEA
Performed by? Chemistry
Sendout? no
Price range $$$
In House Availability Monday-Friday
Saturday & Sunday, 12 pm - 8 pm
Principle The Siemens Centaur assay is a two-site sandwich immunoassay using direct chemiluminometric technology.
Interpretation Carcinoembryonic Antigen (CEA)
CEA can be elevated in several malignancies, especially colorectal carcinoma. However, it can be elevated also in normal subjects, hypothyroidism, pneumonia, pancreatitis, inflammatory bowel disease and smokers. CEA is useful as a tumor marker for assessing therapy. It is recommended preoperatively for suspected or biopsy-proven colorectal carcinoma. Post-resection, CEA levels should return to reference range in 4-6 weeks. Serial determinations at 4-6 week intervals thereafter are recommended. CEA increases 4-6 months before a recurrence is clinically apparent. A rapid rise suggests hepatic or bony metastases, a slow rise suggests local recurrence. In small cell carcinoma of the lungs and metastatic carcinoma of the breast, CEA can be followed to assess chemotherapy.
Container type gold top gel tube
Amount to Collect 2 mL
Sample type Clotted Blood
Normal range Non smokers: 0 - 2.5 mcg/L; Smokers: 0 - 5.0 mcg/L.
NOTE: Values obtained with different CEA assays cannot be used interchangeably. Additional sequential testing should be carried out to confirm baseline values.
Synonyms CEA;
Stability Serum is stable 2 days at 2-8°C; one month at 20°C.
Interferences 1. Auto- (rheumatoid factor) and heterophile antibodies in human serum can react with reagent immunoglobulins, interfering with in vitro immunoassays. Patients routinely exposed to animals or to animal serum products can be prone to this interference. Anomalous values may be observed. The most common, although not exclusive, interference seen in immunometric ("two-site," or "sandwich") assays is a spuriously high value. Results inconsistent with clinical findings or previous laboratory values can be investigated by the laboratory for this phenomenon. Call the Clinical Chemistry Laboratory Medicine Resident (x65527, pager 415-443-2311).

2. A paradoxical, false low result may rarely occur when patient samples with extremely high concentrations of peptide/protein analytes (e.g. AFP, hCG, PSA, etc.) are measured by immunometric ("two-site," or "sandwich") assays. For example, a true value of 3,000,000 U/L could be reported as <5 or 21 U/L. This phenomenon is called the "high dose hook effect." Results inconsistent with clinical findings or previous laboratory values can be investigated by the laboratory for this phenomenon. Call the Clinical Chemistry Laboratory Medicine Resident (x65527, pager 415-443-2311).
References 1. Bayer 111773 Rev. 2003-04. Siemens Medical Solutions Diagnostics, Malvern, PA.

2. Henry, JB, ed.: Clinical Diagnosis and Management by Laboratory Methods, 20th ed. Philadelphia, WB Saunders, 1033, 1038; 2001.

3. Tietz, N.W. Textbook of Clinical Chemistry and Molecular Diagnosis, ed. 4. St. Louis, MO: Elsevier Saunders, 768-769; 2006.
CPT coding 82378
Last Updated 10/17/2012 10:01:23 AM
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