Carcinoembryonic Antigen (CEA), Serum/Plasma

CEA, a member of the immunoglobulin superfamily, is a glycoprotein exhibiting considerable heterogeneity due to variations in its carbohydrate side chains. Structural similarity of CEA to certain immunoglobulin-related proteins and the fact that alterations in cell adhesion are causally involved in cancer invasion and metastasis suggest that CEA might act as an adhesion molecule. However, there is no direct evidence that CEA is causally involved in cancer dissemination. As with most tumour markers, both the concentration of CEA and proportion of patients with increased values tend to increase with increasing disease stage. In colorectal cancer, well-differentiated tumours secrete more CEA than poorly differentiated tumours.

CEA is a tumour marker of the gastrointestinal tract especially colorectal cancer. However, it should not be used to diagnose cancer rather, it should be used as an aid in the diagnosis and prognosis of colorectal cancer; high CEA levels predict adverse outcome. The level of CEA is affected by the grade of tumour, site of tumour, liver status, smoking, bowel obstruction and ploidy status of tumour.

1 ml Serum 1 ml K2, K3-EDTA Stability: 7 Days at 2-8 °C > 7 Days at -20 °C

Smoker: Up to 5.5 µg/L Non-smoker: Up to 3.8 µg/L