Tumor markers tests (cancer biomarkers)
Analysis of the statistics for the last few years indicates the growing incidence of the population of the globe by various forms of cancer (cancer). This is due to the increase in life expectancy of modern man.
Among the causes of death cancer is now came in second place after cardio- and cerebrovascular diseases.
Reduced morbidity and mortality from malignant neoplasms (cancer diseases) oncologists associated with the widespread introduction of prevention and early diagnosis. In 50% of patients with cancer detected by conventional diagnostic methods cancer is generalized.
Detection of malignant tumors in the early stages of their development allows for successful treatment in 90% of patients.
In oncology for early diagnosis, monitoring the treatment of malignant tumors and early detection of metastases are widely used detection of tumor markers.
The term "tumor markers" or "cancer biomarkers" covers a wide range of biological substances with different characteristics (onco-fetal and onco-placental antigens, tumor-associated antigens, enzymes, hormones, products of oncogenes, plasma proteins, metabolic products, bioactive peptides, etc.), but united by a relationship with a malignant process, which makes possible their use in the diagnosis, screening, monitoring and prognosis of the disease in patients with malignant tumors.
The diagnostic significance of specific tumor markers depends on the sensitivity and specificity of detecting tumors with its use, and the prevalence of the disease in the population. The "ideal" tumor marker should be organospecific, its concentration should correlate with the size of the tumor, stage of disease, prevalence of the process, prognosis and response to treatment.
General characteristics of tumor markers:
- the primary use of tumor markers is to assess the effectiveness of the treatment, monitoring and prognosis of the disease, early detection of recurrence and metastasis
- some tumor markers have been successfully used in the differential diagnosis in an unknown primary tumor (for example, NSE in lung cancer, CA 15-3 in breast cancer)
- rate of decline in marker levels after surgery or radiotherapy and chemotherapy may be the first sign of successful operation and treatment and prognosis marker
- must be considered, that there is no tumor marker with 100% specificity in relation to tumor and normal level of tumor marker does not exclude the presence of malignancy or recurrence
- due to the heterogeneity of tumors is often advisable to use several different markers
Monitoring of tumor markers is also used to monitor the effectiveness of tumors radio- and chemotherapy.
Used tumor marker test could provide the highest possible accuracy of cancer diagnosis and it must meet at least four requirements:
- Test result should be interpreted individually, without any correlation with a certain average value.
- The result of the test should quantitatively reflect changes in clinical course of malignant process — decreased with tumor regression, and increased with the progression of the disease.
- Test result should identify subclinical course of malignant process, and thus confirm the achievement of complete remission or relapse to diagnose its clinical manifestations.
- The test must be so reliable that based on the result (indicative of relapse) clinician could take action even in the absence of cytological confirmation.
A brief description of some tumor markers tests commonly used in medical diagnostics, you can explore the links below:
- β-2 microglobulin (beta-2)
- Alpha-fetoprotein (AFP)
- Squamous cell carcinoma antigen (SCC)
- S100 protein tumormarker
- Mucin-like carcinoma-associated antigen (MCA)
- Neuron-specific enolase (NSE)
- Prostate-specific antigen (PSA) test
- Cancer associated antigen 549 (CA 549)
- CA 19-9, CA 72-4, CA 50, CA 15-3 and CA 125 tumor markers (cancer antigens)
- Carcinoembryonic antigen (CEA)
- Thyroglobulin (Tg)
- Tissue polypeptide antigens (ТРА, TPS)
- Cytokeratin-19 fragment (CYFRA 21-1)
- Human chorionic gonadotrophin (hCG)