Tumor markers are specific antigens (proteins) that are found in the blood in the presence of certain malignant tumors in the body.
It should be noted that a normal level of tumor markers does not yet indicate the absence of a tumor, as well as an increased level of its presence. An increase in the level of tumor markers is also observed in inflammatory processes. Thus, a blood test for the presence of tumor markers is only of secondary importance.
Both in screening (detection of tumors in the early stages) and in clinical practice, the use of tumor markers is rather limited. The definition of tumor markers is important, mainly in ovarian cancer and prostate cancer.
If an increased level of one of the tumor markers is detected, additional research methods are required, without which the final diagnosis is impossible.
If the diagnosis of cancer is confirmed, and at the same time a high level of tumor markers is found, then the dynamics of their level over time allows, oncomarkers, to correct the selected methods of treatment.
What are biomarkers
Biomarkers are substances that are detected in the tissues and fluids of a patient at an increased concentration. The terminology “tumor marker” is used only in oncology, but biomarkers have a broader concept.
Biomarkers can act as:
Indicator of the presence / absence of cancer.
The indicator of the effectiveness of drugs.
The criterion of effectiveness in clinical trials.
Determining the response to therapy.
Safety / toxicity characteristics of medicinal products.
In particular, they can be used to search for the mechanisms of action of medicines.
Therefore, a biomarker is a modern opportunity for the unmistakable determination of pathology, the stage of the disease, as well as the correct choice of medicines and therapy.
In order to choose the right biomarkers for research, you need to answer two questions:
What is the specific purpose of using a biomarker (detecting cancer at an early stage, assessing the effect of drugs on the course of the disease, identifying the target of drugs)?
What source of biomaterial will be investigated (liquid or tissue)?
The reliability of the examination result, of course, depends on the qualified and correct choice of a biomarker. And only a professional oncologist can cope with this task.
When are tumor markers needed?
Regarding oncology, if a person has a high risk factor for getting cancer or if he feels any anxiety about this, of course, you should contact an oncologist and donate blood to determine the level of tumor markers.
If cancer has already been identified, tumor markers will be needed to choose the right treatment tactics and select the most effective therapies.
It’s important to know! It is strongly not recommended to resort to self-examination without the advice of an oncologist. Indeed, in this case, you can get both false-negative and false-positive results, the decoding of which without the help of a specialist will not be possible. Subsequently, all this will lead to false calmness of the patient, complications and the rapid development of tumor processes.
It should be remembered that the presence of various chronic diseases, stress, inflammatory processes, infections, hormonal imbalance, can also give false indicators of the concentration of tumor markers, which means that one analysis cannot be stopped.
In addition, there is no universal tumor biomarker that could be found in every type of cancer, therefore, in this case, the high professionalism of the oncologist, who will be able to select the most correct type of tumor marker for research, plays an important role.
How and what tumor markers are used
Different tumor markers identify different types of tumors. And only in exceptional cases, several tumor markers characterize the same type of cancer, or vice versa, the same tumor marker can characterize several types of oncopathologies.
Therefore, for the reliability of the result, several types of biomarkers are analyzed simultaneously.
To determine a specific type of cancer, the following are used:
PSA (prostate-specific tumor marker).
This antigen is produced by malignant cells of the prostate tumor. The normal level of tumor markers is 4 ng / ml. Exceeding this norm indicates the possible presence of prostate cancer.
CA-125 and HE 4 (ovarian specific antigen).
The rate of this tumor marker should not exceed 35 units / ml. In addition, CA-125 can be detected in breast cancer and bronchial anomalies.
CEA or CEA (cancer embryonic antigen).
The norm of the tumor marker is 5 ng / ml, everything that is higher than this indicator requires additional research. Since, a high concentration of this antigen may indicate the development of cancer of the stomach, intestines, ovaries, breast, pancreas and thyroid cancer.
AFP (alpha-fetoprotein https://en.wikipedia.org/wiki/Alpha-fetoprotein).
This tumor marker is used to diagnose liver cancer. The antigen rate is 15 ng / ml. Also, with the help of AFP, it is possible to determine cancer of the ovaries, testicles and gallbladder.
To summarize, we would like to emphasize once again that the deviation of the test result from the norm is not the final indicator for the diagnosis of “cancer”! A competent oncologist will always prescribe additional diagnostic methods that should either confirm this diagnosis or refute it.