Tumour markers
What serum tumour markers can and can't do, with worked results; the markers that diagnose (AFP, beta-hCG, PSA), the ones that only monitor (CEA, CA 125, CA 19-9, CA 15-3), half-life kinetics, the risk of malignancy index, and the false positives and assay traps examiners like.
Tier 1Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Most serum tumour markers are glycoproteins made by normal and inflamed tissue as well as cancer. They are poor at screening and diagnosis and better at monitoring a cancer already known to make them.
- The exceptions, where a marker diagnoses, stages or changes treatment on its own: AFP and beta-hCG in germ cell tumours, AFP in hepatocellular carcinoma, PSA in prostate cancer, and paraprotein in myeloma.
- Send a marker to answer a question. A panel of CEA, CA 125, CA 19-9 and CA 15-3 in an unwell patient without a diagnosis creates false trails (Carcinoma of unknown primary).
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Sources
- RCPA Manual: pathology tests (tumour marker entries)AU/NZRoyal College of Pathologists of Australasia
- Sturgeon CM et al. National Academy of Clinical Biochemistry laboratory medicine practice guidelines for use of tumor markers in testicular, prostate, colorectal, breast, and ovarian cancers. Clin Chem 2008;54:e11-79National Academy of Clinical Biochemistry (Clinical Chemistry), 2008 (no newer NACB version, November 2026)
- Clinical practice guidelines for PSA testing and early management of test-detected prostate cancerAU/NZProstate Cancer Foundation of Australia, 2026 (NHMRC approved May 2026)
- Clinical practice guidelines for the prevention, early detection and management of colorectal cancerAU/NZCancer Council Australia
- Rustin GJS et al. Definitions for response and progression in ovarian cancer clinical trials incorporating RECIST 1.1 and CA 125 agreed by the Gynecological Cancer Intergroup (GCIG). Int J Gynecol Cancer 2011;21:419-23Gynecologic Cancer InterGroup, 2011
- Khatcheressian JL et al. Breast cancer follow-up and management after primary treatment: ASCO clinical practice guideline update. J Clin Oncol 2013;31:961-5American Society of Clinical Oncology, 2013
- Van Poznak C et al. Use of biomarkers to guide decisions on systemic therapy for women with metastatic breast cancer: ASCO clinical practice guideline. J Clin Oncol 2015;33:2695-704American Society of Clinical Oncology, 2015
- Harris L et al. American Society of Clinical Oncology 2007 update of recommendations for the use of tumor markers in breast cancer. J Clin Oncol 2007;25:5287-312American Society of Clinical Oncology, 2007
- Last updated
- 14 November 2026
What changed
- 14 November 2026 Personal emails, About story and Australian-style copy