Markery nowotworowe - prosty i szybki sposób na wykrycie raka?

The video thumbnails were created by the creator of this channel or downloaded under CC0 (Creative Commons Zero) from public domains and do not infringe on anyone's copyright in any way. Tumor markers are proteins or glycoproteins excreted or secreted by cancer cells into the blood, or embedded in the cell membrane, or even located in the cytoplasm or nucleus. Markers secreted into the blood can be detected in the laboratory using monoclonal antibodies—ELFA or EIA—after taking a blood sample from the antecubital vein. However, tumor markers located in the cell membrane, cytoplasm, or nucleus can only be detected after collecting cells for cytological examination—a swab or fluid from a body cavity—or tissue samples for histopathological examination—collected, for example, during a gastroscopy. Sometimes, tumor markers are detected on entire excised tissues; for example, on a removed skin mole, markers characteristic of melanoma are sought. These markers are usually ordered by a pathologist depending on diagnostic needs, after initial microscopic examination of the tissue, stained with eosin and hematoxylin. By definition, tumor markers should possess the following characteristics, which characterize a so-called ideal marker: limited occurrence only in malignant tumor cells each tumor has a specific, distinct marker not found in other tumors high diagnostic sensitivity high diagnostic specificity accessibility to existing laboratory methods ease of obtaining test material In reality, no tumor marker meets these characteristics, as increased concentrations or expression of most tumor markers are also observed in non-cancerous diseases – in inflammatory conditions, benign tumors, and even physiological conditions. Therefore, it must be concluded that there is no ideal marker. Furthermore, in many malignant tumors, tumor marker concentrations may be within the normal range. Oncological diagnostics should never be limited to determining tumor markers alone, but can be a valuable complement to routine procedures and other tests. The diagnostic sensitivity of tumor marker testing can be increased by measuring several markers simultaneously. Furthermore, a very high increase in marker concentrations—several thousand or hundred times above the acceptable norm—is indicative of cancer. An increase in marker concentration after cancer removal also suggests recurrence and can precede the point at which this recurrence becomes diagnosable using other methods, even by several months. The most commonly tested tumor markers are: PSA – in prostate cancer CA 125 – in breast and ovarian cancer CA 19.9 – in pancreatic and stomach cancer AFP – in liver and testicular cancer LDH – in testicular cancer CEA – in colon, lung, and breast cancer S-100 – in melanoma HMB – in melanoma Vimentin – in non-epithelial tumors (sarcomas) Cytokeratin – in cancers Ki-67 – tumor malignancy index Melan A – in melanoma PgR – in breast and ovarian cancer ER – in breast and ovarian cancer HERR-2 – in lung, stomach, and breast cancer Calcitonin – in medullary thyroid cancer Only PSA testing has been approved in Poland as a screening method for prostate cancer; in many countries, this test is not performed at all. In Poland, every clinician or oncologist always tests PSA before sending biopsies for histology. In some cases, PSA is normal even though the patient has cancer, in others, PSA is elevated even though the patient does not have cancer. It is therefore important to remember that testing for tumor markers in a diagnostic laboratory does not eliminate the need for other, more invasive tests, and an increased tumor marker concentration does not necessarily indicate cancer. References: 1. Kilpatrick, E. BMJ. 2009 Sep 22, 339:b3111. 2. Sturgeon CM, Hoffman BR, Chan DW, Ch'ng SL, Hammond E, Hayes. Clin Chem 2008;54(8):e1-10. 3. Duffy MJ. Eur J Intern Med 2007;18:175-84. 4. Barry MJ. N Engl J Med 2009;360:1351-4.