True about carcinoembryonic antigen (CEA)-a) Useful for screening of Ca. colonb) Gives confirmative evidence of Ca. colonc) Helpful for follow-up after resectiond) Levels decrease immediately after resection of tumore) Tumour size correlates with CEA level

Carcinoembryonic antigen (CEA) CEA is produced by fetal gut, pancrease and liver. It is a glycoprotein. It can be used as a tumor marker in colorectal cancer (major use) and also in pancreatic, lung, breast, or ovarian carcinoma. It is also increased in some non-neoplastic disorders, e.g. alcoholic cirrhosis, hepatitis, IBD (CD, UC), smoking, pancreatitis . Uses of CEA in colon cancer Screening Response to surgery after complete surgical resection, CEA should disappear in 6 weeks (not immediatly), Persistant beyond 6 week indicates residual tumor. Higher level suggests high tumor burden (size) → Prognostic value. For follow up to see recurrence. CEA assays lack both specificity and sensitivity → can not be used to confirm the diagnosis.