CEA (carcinoembryonic antigen) is elevated in colorectal cancer but is NOT used for diagnosis. Its MOST appropriate clinical role is:

• A Screening in high-risk populations aged >50 years
• B Differentiation of benign from malignant colonic polyps
• C Post-operative monitoring for recurrence after curative resection ✓
• D Prediction of response to chemotherapy before treatment initiation

Explanation

CEA is a glycoprotein normally expressed in foetal gut that re-emerges in colorectal and other cancers. It lacks the sensitivity and specificity for screening because it is also elevated in smokers, IBD, liver disease, and other cancers. After curative resection, serial CEA measurement is the recommended approach for early detection of recurrence (rising CEA prompts imaging to detect metastases). CEA is also used to monitor treatment response in advanced disease.

Reference: Harper's Illustrated Biochemistry, 32nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.