Carcinoembryonic Antigen (Blood)

Diagnostic Use

Approximately 13% of otherwise healthy smokers have CEA levels of up to 5.0 ug/L
This is a non-specific test which may be increased in both benign and malignant diseases. It is therefore of limited use for diagnosis.

Its main value is for monitoring patients with known tumours which secrete CEA.  Levels fall with successful treatment and a rise may indicate tumour recurrence.

CEA may be elevated with the following carcinomas:

• Colorectal (70%)
• Pancreatic (55%)
• Gastric (50%)
• Lung (45%)
• Breast (40%)
• Uterine (40%)
• Ovarian (25%)

Benign conditions causing elevated CEA include:

• Cirrhosis  (45%)
• Emphysema (30%)
• Rectal polyps (5%)
• Benign breast disease (15%)
• Ulcerative colitis (15%)

Analysis of pancreatic cyst fluid for CEA (in combination with e.g. amylase and CA 19-9) have been used in the differential diagnosis of pancreatic cysts. Although sensitivity may not be high and cannot distinguish mucinous cystadenoma from cystadenocarcinoma, high specificity can be achieved using specific cut points to distinguish mucinous from non-mucinous cysts e.g. CEA of <5ug/L – unlikely to be mucinous cyst ; CEA >800ug/L – unlikely to be a pseudocyst. (see LabPLUS testguide under Pancreatic Cyst Aspirate (Biochemistry / Tumour markers).

Reference Intervals

0 – 3.0 µg/L (nonsmokers)

CEA can go up to 5 ug/L in healthy smokers