In medicine, CA 15-3 (tumor marker) is used in the laboratory diagnosis of breast cancer, its increase in blood serum indicates the presence of pathology, especially in advanced stages and the presence of metastases in the body. This marker is a very important indicator that has a high specificity; a study is used to determine the quality of the treatment, as well as recurrence or elimination of metastases. The CA 15-3 analysis is also used to diagnose such a formidable breast disease as carcinoma, from the membranes of which it actually appears in the blood serum.
What is a tumor marker
Tumor markers are substances of various nature that can be found in liquid media (most often in urine or blood), in a certain concentration they can indicate the presence of oncological pathology. In the diagnostic process, markers depend on tumor specificity and sensitivity. Specificity is the percentage of negative tumor markers in a he althy individual. Sensitivity is the percentage of a positive result obtained in patients with oncological pathology. Today, not a single specific antigen has yet been found that would directly and with a hundred percent probability be able to help make an oncological diagnosis. Tumor markers can also be elevated in inflammatory diseases of various nature, and will also increase in a benign process.
Normally, cancer markers are produced only by embryonic cells. Recently, doctors often began to find cancer markers in young people and even children. This happens due to the constantly deteriorating environmental situation, the presence of bad habits or concomitant pathology.
Better
It is best to determine the oncomarker in dynamics, then it has more diagnostic value than a one-time diagnosis. The rate at which the indicator increases indicates the rate of tumor growth, as well as the presence of metastases. Even after the treatment, the cancer antigen CA 15-3 for a period of six months to nine months is able to get ahead of the development of the clinical picture. About 80% of women with metastasized breast cancer come to the doctor with elevated levels, in 20% of those diagnosed with an oncological process in the first or second stage, the marker also increases.
When to appoint
The material for the study is blood, SA15-3 marker is taken for the purpose of constant and timely monitoring, detection of early recurrence of the disease, metastasis and the effectiveness of the treatment. Also, the differential diagnosis of the malignant process and mastopathy is not the last.
What is CA 15-3 (tumor marker)
It is a high molecular weight mucin-type glycoprotein and has a molecular weight of 300 kilod altons. Normally, the marker is part of the surface of the membranes of secreting cells. It can be detected with carcinoma of the breast, but the presence of this laboratory indicator is also possible with carcinoma of the lungs, ovaries, as well as the gastrointestinal tract and pancreas.
In addition to the fact that CA 15-3 (tumor marker) can be produced by tumor tissue, it can be increased in other pathological conditions in which cell turnover increases. This and other glycoproteins from the body, in particular from the blood, are excreted with the help of the liver, and it is precisely its pathology, in particular cirrhosis, that can become an additional link in the diagnosis.
Importance of analysis
Breast cancer is a rather insidious disease that is difficult to diagnose in the early stages. It is also worth taking a CA 15-3 blood test for the purpose of prevention, then oncology has no chance at the very early stage of the process. In addition, this will allow timely diagnosis of liver pathology. Particular attention should be paid to the risk group, these are patients who have undergone treatment,or women in menopause. In addition, it is possible to establish whether the process is benign or, conversely, requires immediate treatment and specialist intervention.
Diseases requiring analysis
The first thing you should take the CA 15-3 analysis for is, as already mentioned, breast cancer, carcinomas, and metastasis of the process. Since this is a protein, and the main place of its metabolism is the liver, problems with it can also give an increase. First of all, in this case it is worth thinking about cirrhosis, in this case, CA 15-3 rises, the norm in this case is up to 50 U per ml. It is also worth paying attention to additional methods for examining the liver, primarily ultrasound and histological. It is the histologist who can put the final point in the diagnosis. Since carcinoma can develop not only in the mammary gland, but also in the stomach, pancreas, ovaries and lungs and metastasize from these organs, the CA 15-3 marker is of particular importance for men. The dynamics of the analysis will allow you to judge the treatment and its quality.
Often, the marker also increases with a benign process, these are primarily the aforementioned diseases of the mammary glands. Autoimmune diseases can produce elevated CA 15-3. The tumor marker can also be increased in such a physiological state of the woman's body as pregnancy, especially in the third trimester, in this case the indicator is up to 50 U / ml.
What? Where? When?
You need to hand overjust blood from a vein, which will be taken by a nurse in the treatment room. It is only worth remembering that on an empty stomach it is necessary to take an analysis of CA 15-3, decoding it in this case will be more accurate. Serum is examined, in which the indicator of oncological protein is determined. The analysis time is three hours - and the result is ready. An oncologist, mammologist or gynecologist can prescribe an analysis. The study of blood serum takes place using an immunochemiluminescent analysis, and half an hour before the test, you should refrain from smoking.
From the moment of the last meal, at least 8 hours and no more than 14 should pass. Blood is also donated before the start of taking medications, and also not earlier than 1-2 weeks after stopping them. If it is impossible to refuse medicines, the referral should indicate which drugs the person is taking and in what dose. The day before taking the analysis, it is worth limiting physical activity, as well as giving up fatty and fried foods.
Results obtained
The reference value of the determined indicator should be less than 31.3 units per milliliter. As CA 15-3 increases, one can judge the stage of the process, and the more the disease is started, the greater the tumor in the breast tissue. Cancer metastasizes primarily to the bones and / or liver, which can also be evidenced by the analysis. Do not forget that at an early stage of the process, CA 15-3 (tumor marker) may not exceed the norm at all. According to statistics, the percentage of such patients is from 25 to 30, cancer tissuesimply does not produce that specific protein. In the case of a constant increase in concentration against the background of ongoing treatment, one can safely think of its insufficient effectiveness or, on the contrary, of a relapse of the process.
Result may be distorted
Concomitant pathology can affect the performance of the analysis, and this should be taken into account. There is a whole list of diseases that, against the background of the development of the oncological process, can distort the result and put the doctor on the wrong track. Such pathology includes autoimmune processes, tuberculosis, sarcoidosis. In the presence of this pathology, the result may be false positive.
In the diagnosis of breast cancer, the analysis for CA 15-3 will be more valuable if the cancer-embryonic antigen is determined at the same time. And it is best to conduct the test itself a few weeks after the start of the treatment.
Other tests
For diagnosis, you can donate not only blood, the material can also be pleural fluid, ascitic (especially with cirrhosis), spinal, cystic (biopsy of a breast or ovarian cyst) fluid. In order to judge pathology, it is necessary to focus on certain norms. In a he althy body, the oncomarker does not exceed the rate from 0 to 22 IU per milliliter, from 22 to 30 IU per milliliter should be considered a borderline condition, an analysis is considered a pathology, in which 30 IU per milliliter or more are detected.
Prevention matters
Tumor markers are not the only research method that allows doctors to make the correct diagnosis. In the presence of oncologymarkers will allow to control the effectiveness of the treatment or to identify the disease at an early stage of its development. You need to take an analysis at least once a year, especially after 35-40 years old.
Along with the determination of oncological markers, examination of the patient using instrumental methods, as well as a comprehensive clinical examination, is not excluded. With a high CA 15-3 and the absence of any change during the examination of the mammary glands, you should not relax, the oncological process can also be hidden in other organs, for example, in the intestines, liver, ovaries or uterus. The presence of this antigen in men indicates problems with the liver or gastrointestinal tract, for the purpose of prevention, it is necessary to determine CA 15-3 in them as well.
Only a specialist will help interpret the analysis, because independent interpretation can lead to psychological disorders or stress, although an increase in markers can also be observed in a benign process. Only a specialist can prescribe an analysis after a comprehensive clinical examination and after a thorough history taking. Oncological markers give specialists the opportunity to diagnose a malignant process early, but only with an integrated approach can one judge the final result.
