The Carcinoembryonic Antigen (CEA) test is a blood test that measures the levels of CEA, a type of protein typically found in the tissue of developing fetuses. In healthy adults, blood levels of CEA are very low. However, certain types of cancers can cause these levels to rise significantly, most notably colorectal cancer, as well as cancers of the pancreas, breast, lungs, and stomach.
Doctors primarily use the CEA test to monitor how well cancer treatments are working, check for disease recurrence after therapy, or help stage certain malignancies. It serves as an essential biomarker for ongoing cancer management.