CARCINOEMBRYONIC ANTIGEN (CEA)

CLINICAL UTILITY:

CEA (a group of glycoproteins) is a tumor-associated antigen found in a variety of malignant conditions, but also found in fetal and normal body fluids. Elevated serum levels of CEA have been associated with adenocarcinoma of the colon, rectal carcinoma, carcinoma of the pancreas and with malignancies of the stomach, breast, lung, prostate, and bladder. Increases also have been found in certain lymphomas and in acute and chronic leukemias.

Nonmalignant conditions in which CEA levels are elevated include cirrhosis of the liver, ulcerative colitis, diverticulitis, rectal polyps and some benign tumors, and heavy tobacco smoking.

Measurement of CEA levels is not recommended for initial diagnosis, since increases occur in so many malignant and nonmalignant conditions. The test for CEA is most useful in monitoring patients with known malignancy during treatment and following remission. Rising CEA levels suggest progressive malignant disease, persistently elevated levels suggest metastatic and/or residual disease, and declining values generally indicate successful treatment and a favorable prognosis.

METHOD DESCRIPTION:

To assay for serum or plasma CEA levels, a solid phase enzyme immunoassay (EIA) based on the "sandwich" principle is used.

REFERENCE RANGE:

0-5 ng/ml

SPECIMEN REQUIREMENTS:

2 ml of either serum or plasma. Freeze.