AFP (alpha-fetoprotein) is elevated in hepatocellular carcinoma. However, which combination of tumor markers and associated cancers is INCORRECTLY paired?
- A Beta-hCG — gestational trophoblastic disease and germ cell tumors
- B CA 125 — epithelial ovarian cancer (serous subtype)
- C CEA — medullary carcinoma of thyroid ✓
- D NSE (neuron-specific enolase) — small cell lung carcinoma and neuroblastoma
Correct answer: C. CEA — medullary carcinoma of thyroid
Explanation
CEA (carcinoembryonic antigen) is a marker for colorectal cancer, not medullary thyroid carcinoma. The specific tumor marker for medullary thyroid carcinoma is calcitonin (and secondarily CEA, but calcitonin is the primary/specific marker). NSE is a glycolytic enzyme expressed in neurons and neuroendocrine cells, elevated in SCLC and neuroblastoma. CA-125 and beta-hCG pairings are correct. Medullary thyroid carcinoma arises from parafollicular C-cells which secrete calcitonin.
Reference: Harper's Illustrated Biochemistry, 32nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.