PathologyNeoplasiahigh-yield
Tumour markers and their benign traps
The high-yield tumour markers with their associated malignancies and the benign conditions that also raise them, arranged as one recall table.
6 min read · updated 2026-08-24
Why markers mislead
Tumour markers are not diagnostic — they are best for monitoring treatment response and detecting recurrence. Almost every one rises in some benign state, and that benign cause is the favourite exam trap. Learn the marker with its trap attached.
The core table
| Marker | Classically associated tumour | Benign / non-malignant causes that also raise it |
|---|---|---|
| AFP | Hepatocellular carcinoma; non-seminomatous germ cell (yolk sac) | Pregnancy (open neural-tube defects ↑), cirrhosis, hepatitis, normal foetus |
| CEA | Colorectal carcinoma (monitoring) | Smoking, IBD, pancreatitis, cirrhosis, peptic ulcer |
| CA-125 | Ovarian (epithelial) carcinoma | Menstruation, pregnancy, endometriosis, PID, ascites, cirrhosis |
| CA-19-9 | Pancreatic carcinoma; biliary | Pancreatitis, cholangitis, obstructive jaundice (Lewis-negative persons make none) |
| PSA | Prostate carcinoma | BPH, prostatitis, DRE/instrumentation, recent ejaculation, catheterisation |
| Beta-hCG | Gestational trophoblastic disease; germ-cell (choriocarcinoma, seminoma) | Normal pregnancy |
| CA-15-3 (& CA 27-29) | Breast carcinoma (monitoring metastatic disease) | Benign breast disease, hepatitis, pregnancy, lactation |
| Calcitonin | Medullary thyroid carcinoma (from parafollicular C cells) | Rises little benignly; also screens in MEN 2 kindreds |
| Chromogranin A | Neuroendocrine tumours / carcinoid, phaeochromocytoma | PPI use, atrophic gastritis, renal/hepatic impairment |
Patterns that unlock questions
- AFP + beta-hCG together — the germ-cell duo. Yolk-sac → AFP, choriocarcinoma → hCG, pure seminoma → neither AFP (may have mild hCG). "Testicular mass with raised AFP" cannot be a pure seminoma.
- CEA is for follow-up, not screening — a rising CEA after colorectal resection signals recurrence; its smoking elevation is the trap.
- PSA — the benign gland (BPH) and even a digital rectal exam lift it; % free PSA and velocity refine, but the exam point is simply "PSA is not specific for cancer."
- CA-125 in a young woman — think physiological/endometriosis before malignancy.
- Calcitonin is the one marker that is genuinely near-specific — a screening tool in MEN 2 / medullary carcinoma families.
Pearl: a tumour marker answers "is the known cancer coming back?" far better than "does this person have cancer?" — every benign cause in the right-hand column is there to punish anyone who forgets that.
Sources
- Robbins and Cotran Pathologic Basis of Disease, 10e
- Harrison's Principles of Internal Medicine, 21e