From the Guidelines
CEA Level Definition
A CEA level, also known as a carcinoembryonic antigen level, is a blood test used to measure the amount of carcinoembryonic antigen in the blood, with a normal range typically less than 5 nanograms per milliliter (ng/mL) [ 1 ].
Interpretation of CEA Levels
Elevated CEA levels can indicate the presence of cancer, such as colorectal, lung, breast, and pancreatic cancer, but can also be caused by other conditions, including smoking, liver or kidney disease, or certain medications [ 1 ].
- A CEA level of 0-5 ng/mL is considered normal.
- A CEA level of 5-10 ng/mL is considered slightly elevated.
- A CEA level of 10-20 ng/mL is considered moderately elevated.
- A CEA level above 20 ng/mL is considered significantly elevated [ 1 ]. However, the interpretation of CEA levels should always be done in the context of the individual's overall clinical picture and medical history [ 1 ].
Clinical Use of CEA Levels
CEA levels are used in the diagnosis, staging, and monitoring of cancer, particularly colorectal cancer [ 1 ].
- Preoperative CEA levels can assist in staging and surgical planning [ 1 ].
- Postoperative CEA levels can help detect metastatic disease [ 1 ].
- CEA levels are also used to monitor response to therapy in patients with metastatic colorectal cancer [ 1 ].
From the Research
Definition of CEA Level
- CEA (Carcinoembryonic Antigen) is a glycoprotein that can be detected and measured by radioimmunoassay 2
- CEA level is defined as the amount of CEA present in the blood, typically measured in nanograms per milliliter (ng/ml)
Normal CEA Levels
- In healthy individuals, serum CEA level is not influenced by sex, age, blood type, time of blood sampling, or family history of cancer 2
- However, CEA level can be influenced by a history of smoking or inflammatory disease of the bowel, lung, pancreas, and other organs 2
- Currently, CEA positivity is defined as greater than 2.5 ng/ml, but 5 ng/ml may be a more realistic threshold 2
CEA Levels in Cancer
- CEA level may be increased in primary cancer of the gastrointestinal (GI) tract as well as in non-GI neoplasia 2
- Markedly increased (greater than 25 ng/ml) serum CEA values are highly suggestive of metastatic cancer, particularly hepatic metastasis 2
- Serial measurement of CEA levels after surgery in patients with colorectal cancer can detect recurrences early 3, 4
Clinical Usefulness of CEA Levels
- CEA level is not useful for detecting asymptomatic cancer due to its low sensitivity and specificity, particularly for early stages of disease 3
- CEA level can provide prognostic information, with higher preoperative CEA levels associated with advanced or metastatic disease and poorer prognosis 5, 6
- CEA measurement has an important role in the investigation, management, and follow-up of patients with colorectal cancer 5