• Clinical science

Tumor markers

Summary

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 learning cards.

Overview

  • 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, tumor markers can be used to predict therapeutic responses and monitor the effectiveness of cancer treatment!

References:[1][2][3][4][5][6]

Common tumor markers in peripheral blood

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

Carcinoembryonic antigen (CEA)

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

References:[1][1][1][7][7][7][8][9]

Immunohistochemical markers

Definition: antigens on the surface of cells that can be detected via tissue histopathological evaluation; provide information about the origin and immunohistochemical characteristics of these cells (e.g., distribution of protein expression)

Marker Natural occurrence Occurrence in tumors
Vimentin
Desmin
Mesothelin
  • Membrane-bound glycoprotein
Cytokeratin
Neurofilaments
Chromogranin A
  • Secretory granules of neuroendocrine cells
Synaptophysin
  • Secretory granules of neuroendocrine cells
S-100

GFAP

PSA
TRAP
CD20
CD3
CD8
CD4
CD45
  • Malignant lymphoma

References:[1][10]

last updated 10/23/2018
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