Tumour markers. Markers of the first and second choice.
Тumor markers are substances,which prove the presence of tumor or neoplastic process. They are produced by the cancer tissue itself or sometimes by the body in response to cancer growth. Generally, as a term, tumor marker is every parameter, which concentration can be increased in the presence of neoplastic process in the organism. More precisely tumor markers are macromolecules (glycoproteins), + their presence in the organism is associated with neoplastic process or metaplasia of cells.
Tumour markers can be carbohydrates (mucins), proteins, enzymes, hormone, Oncofetal antigens and also blood-group antigen
Limitations: While tumor marker tests can provide very useful information, they do have limitations:
- Many tumor markers may also be elevated in persons with diseases other than cancer.
- Some tumor markers are specific for a particular type of cancer, while others are seen in several different types of cancer.
- Not every person with a particular type of cancer will have an elevated level of the corresponding tumor marker.
- Not every cancer has a tumor marker that has been identified as associated with it.
Tumor Markers use: To screen, diagnose, stage, determine prognosis, Guide choice of treatment, detect recurrence. With regard to staging and prognosis, sharply increased levels of tumor marker point to advanced neoplastic process and are associated with less favorable prognosis, while the lack of changes in the concentration of the tumor marker has better prognosis.
Tumor marker “of first choice” are recommended for every concrete organic localization, which is most frequently with high concentration in the serum.
Tumor marker “of second choice" are used when there is no change in the concentration of the tumor marker of first choice.