Does normal CEA mean no cancer?

Carcinoembryonic antigen (CEA) is a commonly used tumor marker, but it may be normal in some cancers and elevated in others. Here are some factors to consider: Limitations: CEA is not a marker specific to one type of cancer and may be elevated in many types of cancer, but it may also be present in other non-cancer diseases. CEA levels may be elevated in, for example, smoking, inflammatory bowel disease, cardiovascular disease, etc. Cancer type: CEA production and expression may vary by type of cancer. Certain cancers (e.g. lung cancer, stomach cancer, colon cancer, etc.) may be associated with elevated CEA, but there are also some cancers CEA levels may be normal (e.g., bladder cancer, thyroid cancer, etc.). Early cancer: In the early stages of cancer, tumors may be small or not secreting enough CEA to cause normal levels. In addition, some latent or rare cancers may not be routinely detected for CEA. Other factors: CEA levels may also be affected by factors such as test method, time of detection, and individual differences. Therefore, even if CEA is normal, the possibility of cancer cannot be ruled out. The doctor will evaluate other factors on a case-by-case basis and may recommend further tests, such as imaging (such as X-ray, CT, MRI, etc.), pathological biopsy, etc. to confirm diagnosis. For some high-risk groups, such as long-term smokers, patients with familial cancer history, patients with digestive system diseases, etc., even if CEA is normal, comprehensive cancer screening should be carried out regularly in order to detect and treat cancer early. It is important to note that the diagnosis of cancer requires a combination of factors, including symptoms, signs, laboratory tests, imaging results, etc. If there are doubts or concerns about cancer, consult your doctor promptly for detailed discussion and personalized advice. In addition, maintaining a healthy lifestyle, such as smoking cessation, balanced diet, moderate exercise, etc., can help prevent cancer.