Serum CEA (carcinoembryonic antigen) is a cell-adhesive glycoprotein that was discovered in colorectal cancer in 1965, and is hence one of the oldest and most used tumour markers. Its name derives from its normal expression in fetoembryonic liver, gut and pancreas tissue.
Normal range of CEA is <2.5 ng/mL in adult non-smokers and <5.0 ng/mL in smokers.
Its primary significance is in colorectal cancer:
as with most tumour markers it is inappropriate for screening given its poor sensitivity and specificity
used routinely for detecting early postoperative recurrence and metastatic disease, especially liver disease
also used for monitoring response to treatment of metastatic disease
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higher levels are associated with
higher grade tumours
higher stage disease
visceral metastases (especially liver metastases)
CEA may also be elevated in a number of other malignancies:
sarcomas (rare)
Non-neoplastic causes are common and include:
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liver disease
chemotherapy-related liver injury
anaesthetic-related liver injury
COPD and some lung infections
See other tumour markers here