• Clinical science

Tumor markers


Tumor markers are biological substances that can be detected in the blood, urine, or body tissue of some tumor patients. Although some tumor markers may aid in the diagnosis of cancer, they are primarily used for monitoring treatment response and detecting cancer recurrence. Tumor markers are not reliable screening or diagnostic markers due to their low sensitivity (i.e., not elevated in all cancer patients) and low specificity (i.e., also elevated in benign, noncancerous conditions or otherwise healthy patients). The majority of tumor markers that are used in the clinical setting can be detected in the blood. A number of tumor markers can be detected on tissue histopathology. They are also referred to as immunohistochemical markers and can be detected using immunohistochemical techniques. Gene mutations and patterns of gene expression are also increasingly being used as tumor markers.

For details regarding specific carcinomas and the corresponding tumor markers, see the individual cancer articles.


  • Definition: substances (hormones, enzymes, antigens, immunoglobulins, glycoproteins) that can be detected in the blood, urine, or body tissue of some cancer patients
  • Clinical use
    • Detect cancer (does not confirm diagnosis!)
    • Predict therapeutic responses
    • Monitor the effectiveness of cancer treatment
    • Detection of cancer recurrence and screening
  • Limitations
    • Not all patients with cancer have elevated tumor markers (low sensitivity)
    • Not all patients with elevated tumor markers have cancer! (low specificity)

Tumor markers are generally not used to screen for or diagnose cancer. However, once cancer has been diagnosed via biopsy, tumor markers can be used to predict therapeutic responses and monitor the effectiveness of cancer treatment!


Common tumor markers in peripheral blood

Common tumor markers
Tumor marker Associated conditions
Alpha fetoprotein (AFP)

Carcinoembryonic antigen (CEA)

  • Smokers
Prostate-specific antigen (PSA)
Alkaline phosphatase
Placental alkaline phosphatase [7]
Lactate dehydrogenase
Neuron specific enolase (NSE)
  • NSE is released secondary to brain injury (e.g., stroke)
CA 19–9
CA 15–3 and CA 27–29
CA 125
CA 72-4
Chromogranin A
S-100 protein (S100A) and (S100B)
β2 microglobulin (β2M)
Monoclonal immunoglobulins

To recall types of cancer associated with the tumor marker alpha-fetoprotein remember: “Alpha male, HE is a MAN!” H Hepatocellular carcinoma, E Endodermal sinus tumor (yolk sac tumor), M Mixed germ cell tumor, A Ataxia-telangiectasia, N Neural tube defects.

Use the letters in β-hCG to recall the two important conditions associated with the marker. H Hydatidiform mole, C Choriocarcinoma, G Gestational trophoblastic diseaseReferences:[1][1][1][8][8][8][9][10]

Gene mutations and changes in gene expression

Abnormal patterns of gene expressions and gene mutations from tissue samples are increasingly being used as tumor markers.

Gene Conditions
ALK gene rearrangement
  • Non-small cell lung cancer
  • Anaplastic large cell lymphoma
EGFR gene mutation
  • Non-small cell lung cancer
  • Certain head and neck cancers
HER2neu receptor
Estrogen and progesterone receptors


Immunohistochemical markers

  • Definition: Antigens on the surface of cells that can be detected via tissue histopathological evaluation.
  • Clinical relevance
Marker Natural occurrence Occurrence in tumors
  • Membrane-bound glycoprotein
Chromogranin A
  • Secretory granules of neuroendocrine cells
  • Secretory granules of neuroendocrine cells


  • Malignant lymphoma

DesMin is associated with muscle tumors like rhabdoMyosarcomas.

ViMEntin is associated with MEsenchymal tumors.

GFAP stains neuroGlial cells, which are affected in Glioblastomas.


  • 1. Kasper DL, Fauci AS, Hauser SL, Longo DL, Lameson JL, Loscalzo J. Harrison's Principles of Internal Medicine. New York, NY: McGraw-Hill Education; 2015.
  • 2. National Cancer Institute. Tumor Markers. https://www.cancer.gov/about-cancer/diagnosis-staging/diagnosis/tumor-markers-fact-sheet. Updated November 4, 2015. Accessed February 18, 2017.
  • 3. Hussain F, Hussain AN, Haider K, Al Husaini HH. Gynecologic Tumor Markers. In: Gynecologic Tumor Markers. New York, NY: WebMD. http://emedicine.medscape.com/article/269839-overview. Updated January 13, 2015. Accessed February 18, 2017.
  • 4. American Association for Clinical Chemistry. Tumor Markers. https://labtestsonline.org/understanding/analytes/tumor-markers/start/2. Updated April 13, 2016. Accessed February 18, 2017.
  • 5. Diamandis EP, Fritsche HA, Lilja H, Chan DW, Schwartz MK. Tumor Markers: Physiology, Pathobiology, Technology, and Clinical Applications. American Association for Clinical Chemistry; 2002.
  • 6. Ying ACH, Kie AS, Leung LC, Tong NW. Cancer Screening, Early Detection and Prevention Guidelines For Health Professionals. Hong Kong Anti-Cancer Society; 2011.
  • 7. Nielsen OS, Munro AJ, Duncan W, et al. Is placental alkaline phosphatase (PLAP) a useful marker for seminoma?. Eur J Cancer. 1990; 26(10): pp. 1049–54. doi: 10.1016/0277-5379(90)90049-y.
  • 8. Le T, Bhushan V, Sochat M, Petersen M, Micevic G, Kallianos K. First Aid for the USMLE Step 1 2014. McGraw-Hill Medical; 2014.
  • 9. Ishida K, Cucchiara BL. Blood biomarkers for stroke. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/blood-biomarkers-for-stroke?source=machineLearning&search=neuron%20specific%20enolase&selectedTitle=1~36§ionRank=1&anchor=H30408662#H30408662. Last updated May 4, 2016. Accessed February 18, 2017.
  • 10. Campana D, Nori F, Piscitelli L, et al. Chromogranin A: Is it a useful marker of neuroendocrine tumors?. J of Clin Oncol. 2007; 25(15): pp. 1967–1973. doi: 10.1200/jco.2006.10.1535.
  • 11. Ardini E, Magnaghi P, Orsini P, Galvani A, Menichincheri M. Anaplastic Lymphoma Kinase: Role in specific tumours, and development of small molecule inhibitors for cancer therapy. Cancer Lett. 2010; 299(2): pp. 81–94. doi: 10.1016/j.canlet.2010.09.001.
  • 12. Painter JT, Clayton NP, Herbert RA. Useful immunohistochemical markers of tumor differentiation. Toxicol Pathol. 2010; 38(1): pp. 131–141. doi: 10.1177/0192623309356449.
  • Le T, Bhushan V. First Aid for the USMLE Step 1 2015. McGraw-Hill Education; 2014.
last updated 11/23/2020
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