CEA is used as tumor makers worldwide and is proven to be 100% reliable in determining the occurrence of cancer. CEA has a wide range of applications but its role in the postoperative and therapeutic diagnosis of pancreatic, gastric, gynecologic neoplasm is less considerable than in colorectal cancer especially in the detection of liver metastasis in gastrointestinal cancers Longitudinal CEA detects the sensitivity of ∼80% and specificity of ∼70% in cancer.
