Is a positive carcinoembryonic antigen test equivalent to cancer?

A positive carcinoembryonic antigen (CEA) test does not necessarily indicate cancer. CEA is a commonly used tumor marker, with a normal value generally below 5 ng/mL. When CEA levels exceed this normal range, it indeed suggests the possibility of certain malignant tumors, such as colorectal cancer, breast cancer, and lung cancer. However, elevated CEA levels may also result from other non-cancerous conditions, including benign gastrointestinal diseases (e.g., pancreatitis, colitis, colon polyps) or benign liver diseases (e.g., cirrhosis). Additionally, CEA levels are related to the stage of cancer, with more advanced cancers typically associated with higher CEA values. Therefore, a positive CEA test can only serve as an indicator of possible cancer, not as a definitive basis for diagnosis. A final diagnosis must be made by integrating clinical findings, imaging studies, and pathological biopsy results.