Carcinoembryonic antigen (CEA) is produced by several types of cancer, notably colorectal, gastric, and pancreatic cancers, among others.
Understanding CEA and Cancer
Carcinoembryonic antigen (CEA) is a protein normally found in the tissue of a developing baby in the womb. After birth, the level of CEA becomes very low or undetectable in healthy adults. Elevated levels of CEA in adults can sometimes indicate the presence of certain types of cancer or other non-cancerous conditions. It is often used as a tumor marker, particularly for monitoring the response to treatment in patients diagnosed with specific cancers.
Cancers Associated with CEA Production
Based on research, CEA is expressed in a significant number of cases for certain malignancies. According to reference (68):
"Carcinoembryonic antigen (CEA) is expressed in the majority of colorectal, gastric, and pancreatic cancers and also in some breast cancer and non-small-cell lung cancer (NSCLC) (68)."
This means that while CEA is not exclusively produced by cancerous cells, its elevated presence is frequently associated with these specific types of cancer.
Here is a breakdown of the cancers mentioned in the reference that commonly produce CEA:
- Colorectal Cancer: A large percentage of cancers affecting the colon and rectum express CEA.
- Gastric Cancer: Cancers of the stomach often produce CEA.
- Pancreatic Cancer: Many tumors originating in the pancreas are associated with CEA production.
- Breast Cancer: Some cases of breast cancer also show CEA expression.
- Non-Small-Cell Lung Cancer (NSCLC): This major type of lung cancer can also produce CEA in certain instances.
It is important to note that the reference also states: "It is also expressed in some normal colon epithelium." This highlights that CEA expression is not solely limited to malignant tissue.
Summary Table of CEA-Producing Cancers
Below is a table summarizing the cancers where CEA expression is commonly observed, as indicated by the reference:
| Cancer Type | Frequency of CEA Expression (Based on Reference) |
|---|---|
| Colorectal Cancer | Majority of cases |
| Gastric Cancer | Majority of cases |
| Pancreatic Cancer | Majority of cases |
| Breast Cancer | Some cases |
| Non-Small-Cell Lung Cancer | Some cases |
Practical Insights
While CEA is a useful marker for monitoring known cancers, especially colorectal cancer, its levels can be influenced by various factors, including smoking and non-cancerous conditions (like inflammatory bowel disease, pancreatitis, or cirrhosis). Therefore, elevated CEA levels alone are not sufficient to diagnose cancer. A diagnosis requires a comprehensive evaluation by healthcare professionals, including imaging, biopsies, and other laboratory tests.
Monitoring CEA levels can help doctors:
- Check how well cancer treatment is working.
- Detect if cancer has returned after treatment.
In conclusion, CEA is a protein marker produced by several types of cancer, predominantly colorectal, gastric, and pancreatic cancers, and in some cases, breast cancer and non-small-cell lung cancer.
