What does an elevated Carcinoembryonic Antigen (CEA) level indicate?

From the Guidelines

An elevated Carcinoembryonic Antigen (CEA) level indicates a potential presence of colorectal cancer, particularly in the context of monitoring for recurrence or metastasis in patients with a history of colorectal cancer 1.

Key Points

• CEA is not recommended for screening: due to its low sensitivity for detecting occult colorectal cancers 1.
• Preoperative CEA testing: may be useful for staging and surgical treatment planning, and elevated levels (≥ 5 mg/mL) may correlate with poorer prognosis 1.
• Postoperative CEA testing: should be performed every 3 months for at least 3 years after diagnosis in patients with stage II or III disease, to monitor for recurrence or metastasis 1.
• CEA monitoring during systemic therapy: is the marker of choice for monitoring metastatic colorectal cancer, and persistently rising values above baseline should prompt restaging and consideration of alternative treatment strategies 1.
• Non-cancer related causes of elevated CEA: include gastritis, peptic ulcer disease, diverticulitis, liver diseases, chronic obstructive pulmonary disease, diabetes, and any acute or chronic inflammatory state 1.
• Baseline CEA levels: add information in defining prognosis, and a post-operative serum CEA level suggests a worse outcome 1.

Important Considerations

• CEA levels may differ between laboratories and countries 1.
• Chemotherapy may transiently elevate CEA, and a rising CEA by itself should not be considered evidence of disease progression, particularly immediately after starting chemotherapy 1.
• CEA is more cost-effective than radiology for the detection of potential curable recurrence, and is the most sensitive detector for liver metastases 1.

From the Research

Elevated Carcinoembryonic Antigen (CEA) Levels

Elevated CEA levels can indicate a poor prognosis in patients with various types of cancer, including:

• Primary colorectal cancer 2
• Primary pancreatic cancer 2
• Primary breast cancer 2, 3
• Primary lung cancer 2, 4
• Recurrent colon or rectal cancer 2, 5

Association with Non-Cancerous Diseases

Elevated CEA levels are also associated with non-cancerous diseases, such as:

• Lung fibrosis 4
• Uremia 4
• Chronic obstructive pulmonary disease (COPD) 4
• Alzheimer's disease 4
• Aging 4

Clinical Applications

CEA levels can be used to:

• Monitor therapy in cancer patients 2, 5, 3
• Assess the adequacy of surgical removal of a primary colon or rectal cancer 2
• Detect recurrent colon or rectal cancer following surgical resection 2, 5
• Predict treatment response and disease progression in metastatic breast cancer patients 3