CHANGE
CARCINO EMBRYONIC ANTIGEN
CARCINO EMBRYONIC ANTIGEN
EFFECTIVE 08/26/2014
LABSC00009
Effective August 26, 2014, the clinical laboratory will switch methodologies for the Carcino
Embyronic Antigen (CEA) assay. The switch will be from the Siemens ADVIA Centaur
Chemiluminescent Immunoassay to the Abbott ARCHITECT i1000 Chemiluminescent
Microparticle Immunoassay (CMIA).
The comparison studies between the ARCHITECT and the Centaur methods showed some
significant differences, with the ARCHITECT method recovering higher overall. However, the
differences between methods seem to vary between patients, with some patient sample
comparisons showing similar results, but other patients with larger differences. The Deming
regression statistics for the two studies (n=40 for each) were:
Study 1: ARCHITECT CEA ng/mL = 1.59 x Centaur CEA – 0.04 r = 0.96
Study 2: ARCHITECT CEA ng/mL = 1.58 x Centaur CEA – 0.34 r = 0.96
In order to provide some baselining of results, once we begin reporting results using the
new Architect method, we will also provide the Centaur result in a comment attached to
the CEA result. We will baseline patients with values >5.0 ng/mL and with a previous
Centaur result for a 3-month period.
Sample Requirements:
Collect: SST (gold top) or plain red top serum, 4 mL.
Patient Preparation: NA
Storage/Transport: Deliver at room temperature to the laboratory for processing. If sample
cannot be delivered to the laboratory within 24 hours of collection, centrifuge sample and
transport separated serum refrigerated at 2-8°C.
Stability: Separated serum can be refrigerated at 2-8°C for up to 7 days, or frozen at -20°C for
longer storage.
Minimum volume: 0.5 mL serum; (absolute minimum – only pipetable once – 0.3 mL serum)
Unacceptable Conditions: Samples other than serum or samples not held at correct
temperature.
Reference Interval:
0 – 5.0 ng/mL
Additional Information:
The assay should not be used as a cancer screening test. Patients with confirmed carcinoma
frequently have a pretreatment CEA level in the same range as healthy individuals. Elevation in
circulating CEA levels may be observed in smokers, as well as, patients with nonmalignant
disease. For these reasons, a serum CEA level, regardless of value, should not be interpreted as
absolute evidence of the presence or absence of malignant disease. The CEA level should be
used in conjunction with information available from clinical evaluation and other diagnostic
procedures.
LIS mnemonic: CEA
www.testmenu.com/ucdavis
Expected Values
The manufacturer’s study of 1,141 specimens showed the following distribution of CEA values
as tested by the Architect analyzer. In this study, 93.5% of healthy subjects (n=308) had CEA
values of 5.0 ng/mL or less. The distribution table below for malignant disease is derived primarily
from patients representing both active (clinical evidence of disease progression) and inactive (no
clinical evidence of disease progression) disease states.
Distribution of Architect CEA Values in Percent (%)
>3 - 5 >5 – 10
Number of 0 – 3
ng/mL ng/mL ng/mL
Subjects
Healthy Subjects
Smokers
74.2
18.2
6.9
159
Non-smokers
83.2
11.4
5.4
149
Total
78.6
14.9
6.2
308
Nonmalignant Disease
Ulcerative Colitis
72.0
20.0
4.0
50
Rectal Polyps
83.3
10.3
5.1
78
Pulmonary
81.7
20.0
13.3
60
Cirrhosis
47.3
30.0
15.5
110
Hepatitis
70.0
18.7
11.7
60
Renal
60.0
15.0
15.0
20
Malignant Disease
Colorectal
24.0
10.7
10.7
150
Gastric
62.2
5.4
10.8
37
Pulmonary
47.3
19.1
9.1
110
Mammary
62.4
11.1
10.3
117
Ovarian
78.0
7.3
2.4
41
>10
ng/mL
0.8
0.0
0.3
4.0
1.3
5.0
7.3
1.7
10.0
54.7
21.6
24.5
16.2
12.2
Routine Testing: T & TH, dayshift in the Special Chemistry section at the Clinical Lab’s STC
location.
If you have questions or need additional information please contact Laboratory Client Services at
(916) 734-7373 or email pathologyclientservices@ucdmc.ucdavis.edu.
LIS mnemonic: CEA
www.testmenu.com/ucdavis