The key difference between CEA and CA-125 is that CEA is a tumor marker to identify colon cancer, pancreatic malignancies, pancreatitis, cirrhosis, etc., while CA-125 tumor marker mainly identifies ovarian cancer.
A tumor marker is generally any substance in the body that provides information about a cancer. Therefore, tumor markers, in combination with other tests, help healthcare professionals to diagnose and treat certain types of cancers. Tumor markers can be found in the blood, urine, or body tissues. CEA and CA-125 are two different types of tumor markers. They are also proteins. Currently, CEA and CA-125 are used in combination to differentiate epithelial ovarian malignancies from non-ovarian malignancies.
CONTENTS
1. Overview and Key Difference
2. What is CEA
3. What is CA-125
4. Similarities – CEA and CA-125
5. CEA vs. CA-125 in Tabular Form
6. FAQ – CEA and CA-125
7. Summary – CEA vs. CA-125
What is CEA?
Carcinoembryonic antigen (CEA) is a protein normally found in very low levels in the blood of adults. The CEACAM5 gene encodes CEA antigen. The levels of this protein may be increased in certain types of cancer and benign conditions. Moreover, CEA tests are most commonly used to diagnose colorectal cancer. CEA is closely associated with various functions of endothelial cells, including adhesion, proliferation, and migrations of cells.
Figure 01: CEA
CEA blood levels are often increased in colorectal cancer and other cancers such as breast, lung, pancreatic cancer, stomach cancer, liver cancer, and ovarian cancer. Furthermore, CEA blood levels may also rise in non-cancerous conditions, including peptic ulcer, ulcerative colitis, rectal polyps, emphysema, benign breast disease, and inflammations such as pancreatitis or cholecystitis.
What is CA-125?
CA-125 is known as an ovarian cancer-related tumor marker. It is a protein that is encoded by the MUC16 gene in humans. Mucin-16 (MUC-16) is another term for describing CA-125. CA-125 is normally a component of the ocular surface, respiratory tract, and female reproductive tract epithelia. Moreover, CA-125 acts as a lubricating barrier against foreign particles and infectious agents on the apical membrane of these epithelial cells.
Figure 02: CA-125
CA-125 levels also increase in endometrial cancer, fallopian tube cancer, lung cancer, breast cancer, and gastrointestinal cancer. Furthermore, CA-125 level is also altered in other noncancerous conditions such as dry eye and cystic fibrosis.
What are the Similarities Between CEA and CA-125?
- CEA and CA-125 are two different types of tumor markers.
- Both are human proteins with very important normal functions.
- Both are elevated in levels in the blood in some cancers and non-cancerous conditions and hence used to diagnose these conditions.
- CEA and CA-125 are used in combination to differentiate epithelial ovarian malignancies from non-ovarian malignancies.
What is the Difference Between CEA and CA-125?
CEA is a tumor marker used mainly to identify colon cancer, pancreatic malignancies, pancreatitis, cirrhosis, etc., while CA-125 is a tumor marker used mainly to identify ovarian cancer. Thus, this is the key difference between CEA and CA-125. Furthermore, the CEA tumor marker was first identified in 1965, while CA-125 was first identified in 1981.
The infographic below presents the differences between CEA and CA-125 in tabular form for side-by-side comparison.
FAQ: CEA and CA-125
What level of CEA indicates cancer?
In general, a CEA level of more than 2.9 ng/mL is considered abnormal but doesn’t necessarily mean that cancer is present.
What level of CA-125 indicates cancer?
Levels over 35 U/mL may indicate the presence of cancer or other conditions. However, additional testing is needed to confirm the presence of a cancer.
What cancers are high in CEA?
CEA is predominantly associated with gastrointestinal tumors. However, there is a close correlation of high CEA with breast, lung, ovarian, mucinous adenocarcinomas of the cervix, and thyroid cancers. As well
Summary – CEA vs. CA-125
Tumor markers are used to identify different tumors in patients. CEA and CA-125 are two different types of tumor markers. Both are human proteins with important normal functions. However, CEA can be mainly used to identify colon cancer, pancreatic malignancies, pancreatitis, cirrhosis, etc., while CA-125 can be mainly used to identify ovarian cancer. So, this summarizes the difference between CEA and CA-125.
Reference:
1. “Carcinoembryonic Antigen.” An Overview | ScienceDirect Topics.
2. Gentry George T King, MD. “CA 125.” Reference Range, Interpretation, Collection and Panels, Medscape.
Image Courtesy:
1. “PBB Protein CEACAM5 image” By www.pdb.org (Public Domain) via Commons Wikimedia
2. “The Structure of MUC16 EN” By Claudine Rancourt, Isabelle Matte, Denis Lane, and Alain Piché – Claudine Rancourt, Isabelle Matte, Denis Lane and Alain Piché (February 17th 2012). The Role of MUC16 Mucin (CA125) in the Pathogenesis of Ovarian Cancer, Ovarian Cancer Samir Farghaly, IntechOpen, DOI: 10.5772/27672. Available from Intechopen (CC BY 3.0) via Commons Wikimedia