РусскийEnglishEspañol — próximamenteFrançais — bientôtDeutsch — in VorbereitungItaliano — in arrivoAll languages
Carcinoembryonic antigen
A marker used to monitor colorectal and some other cancers. Smoking raises the baseline; not a screening test.
Other names: Carcinoembryonic antigenSection: Tumor markers
Updated: August 31, 2026·MedProtect editorial team Reference information — not a diagnosis or a prescription
In shortCEA is a protein used mainly to monitor colorectal cancer. A typical normal range is 0–2.5 ng/mL (0–2.5 µg/L) in non-smokers and up to 5 ng/mL in smokers. Rising levels after treatment can signal recurrence; benign conditions can also raise it.
Reference ranges
Group
Reference range
Non-smokers — typical range (international reference, not a national standard)
0–2.5 ng/mL (0–2.5 µg/L)
Smokers — typical range (international reference, not a national standard)
0–5 ng/mL (0–5 µg/L)
Range from the MedlinePlus Medical Encyclopedia (international reference, not a national standard). The report's own interval applies. Reference ranges vary between laboratories and assays — use the range printed on your own lab report.
Check your value
Enter the number from your lab report — see how it compares with the typical range. Mind the units shown in the chosen row.
A rough comparison with a typical range, not a diagnosis. Reference ranges vary between laboratories — check the range on your own report and let a clinician interpret the result.
What this marker is
CEA is produced during fetal development and present at low levels in adults. In colorectal cancer, serial measurements after surgery help detect recurrence early and judge response to therapy.
Smokers have a higher baseline, and levels rise in inflammatory bowel disease, liver disease, and lung conditions — an elevated value alone never proves cancer.
When it is high
Colorectal cancer (known disease)A rising trend after treatment can indicate recurrence; a falling trend suggests response.
Other cancersPancreatic, gastric, lung, and breast cancers can raise CEA.
Benign conditionsSmoking, inflammatory bowel disease, liver and lung disease.
When it is low
Expected findingMost healthy people have values in the lower part of the range.
What can skew the result
These factors can shift the value without any disease — worth considering before a retest:
SmokingInflammatory bowel diseaseLiver and lung disease
How to prepare
Blood from a vein; no special preparation.
When a retest makes sense
In cancer follow-up — on the oncologist's schedule. A moderate isolated elevation without a diagnosis is usually rechecked in 1–3 months.
Who usually reviews this result
A result outside the reference range is usually reviewed by: a gastroenterologist or proctologist; an oncologist for known disease. Bring your lab report and any previous results to the appointment.
Names used on lab reports
Your report may use any of these names: CEACarcinoembryonic antigen
Units and conversion
Measured in: ng/mL
ng/mL=µg/L
1 ng/mL = 1 µg/L — the number stays the same. Results are rounded to 2 decimal places.
Several markers on your report?
See how MedProtect explains results in the app: the whole report, a check of the recognized values, and a clear breakdown.
We use cookies and Yandex.Metrika for visit statistics — no advertising tracking and no session recording. The counter loads only after your consent. Privacy policy.