A postmenopausal woman presents with abdominal distension, ascites, and a pelvic mass. Serum levels of which tumor marker are most appropriate for monitoring her response to platinum-based chemotherapy?

• A CA 19-9
• B S-100
• C Calcitonin
• D CA-125 ✓

Explanation

CA-125, a glycoprotein expressed by coelomic epithelium derivatives, is elevated in about 80% of non-mucinous epithelial ovarian cancers and is used to monitor therapy response and detect recurrence, though its sensitivity in stage I disease is poor. CA 19-9 monitors pancreatic and biliary malignancies, calcitonin marks medullary thyroid carcinoma, and S-100 marks melanoma and neural tumors. The clinical picture of ascites with a pelvic mass in this age group points to ovarian cancer.

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.