A serum tumor marker measured by immunometric assay is elevated in approximately 80% of women with advanced epithelial ovarian carcinoma. It is also raised in pregnancy, menstruation, peritonitis, and cirrhosis, which limits its use as a standalone screening test. This marker is:
- A CA 125 ✓
- B CA 19-9
- C CA 15-3
- D S-100 protein
Correct answer: A. CA 125
Explanation
CA 125, a high molecular weight glycoprotein expressed by coelomic epithelium derivatives, is the classic marker for epithelial ovarian carcinoma and is used to monitor therapy response and recurrence. Its benign elevations in menstruation, pregnancy, ascites, and peritonitis explain why it cannot screen the general population alone. CA 19-9 tracks pancreaticobiliary malignancy, CA 15-3 tracks breast carcinoma, and S-100 marks melanoma and neural tumors.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.