CEA

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 tumor 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 tumor 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
• higher levels are associated with
  • higher grade tumors
  • higher stage disease
  • visceral metastases (especially liver metastases)

It can also be found elevated in a number of other malignancies:

• pancreatic adenocarcinoma
• stomach cancer
• cholangiocarcinoma
• lung cancer
• breast cancer
• medullary thyroid carcinoma
• ovarian cancer
• sarcomas (rare)

Non-neoplastic causes are common and include:

• ulcerative colitis and Crohn disease
• alcoholic pancreatitis
• liver disease
  • cirrhosis
  • chemotherapy-related liver injury
  • anesthetic-related liver injury
• COPD and some lung infections
• hypothyroidism
• smoking

See other tumor markers here