The CEA (Carcinoembryonic Antigen) test measures the level of CEA, a protein that is typically produced by cancer cells, especially those found in the digestive tract. CEA can also be produced in smaller amounts by normal cells, but elevated levels are often associated with certain types of cancer.

Why it’s important:

• Cancer monitoring: CEA is commonly used to monitor patients with certain cancers, particularly colorectal cancer, to assess treatment effectiveness, detect recurrence, or gauge the progression of the disease.
• Monitor treatment response: If you’ve had cancer treatment (such as surgery, chemotherapy, or radiation), CEA levels can help track how well the treatment is working and if the cancer is responding.
• Detect recurrence: For individuals with a history of cancer, rising CEA levels can be an early indicator of cancer recurrence, even before symptoms appear.

Non-cancer conditions: CEA can also be elevated in non-cancerous conditions, such as inflammatory bowel disease, cirrhosis and lung diseases.

Conditions associated with elevated CEA levels:

• Colorectal Cancer: The CEA test is most commonly used to monitor colorectal cancer (colon and rectal cancers), as it is often elevated in patients with these cancers.
• Other cancers: Elevated CEA levels can also be associated with breast cancer, lung cancer, pancreatic cancer, gastric cancer, and ovarian cancer.
• Non-cancerous conditions: In some cases, non-cancerous conditions such as chronic obstructive pulmonary disease (COPD), cirrhosis, ulcerative colitis, and pancreatitis can lead to elevated CEA levels.
• Smoking: Smokers tend to have slightly higher CEA levels than non-smokers, so this factor is considered when interpreting results.

Limitations of CEA Testing:

• Not a diagnostic test: CEA is primarily used to monitor cancer, not diagnose it. Elevated CEA levels can be caused by a variety of conditions, both cancerous and non-cancerous, and should not be used alone to confirm the presence of cancer.
• False positive/negative: CEA levels can be elevated in non-cancerous conditions, and not all cancers will cause a rise in CEA. Therefore, it is not a definitive marker for cancer.