Carcinoembryonic Antigen (CEA)

High levels of CEA are normal in healthy, unborn babies. After birth, CEA levels become very low or disappear completely. So, healthy adults should have little or no CEA in their bodies.

If you've been diagnosed with a cancer that can cause high CEA levels, CEA testing may help your health care provider learn more about your cancer and chance of recovery. The test is often used with other tests to check if cancer treatment is working.

To understand your CEA test results, your provider will consider the results of other tests and exams. Ask your provider to explain what your test results mean for your health and treatment.

After surgery to remove a colorectal cancer, CEA levels usually fall back into the normal range within about six weeks. A level that does not return to normal can suggest some cancer was left behind, while a rising level after treatment can be an early sign that the cancer is coming back.

Very high CEA levels (above about 20 ng/mL) in someone with cancer-related symptoms strongly suggest that cancer is present and may have spread.

CEA can also be mildly raised by non-cancer conditions, such as smoking, inflammatory bowel disease, peptic ulcers, hepatitis, and chronic lung disease. This is why CEA is not used to screen healthy people for cancer.

If your CEA levels stay high or go up during or after treatment, your provider will likely order other tests to find out why.