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 with regard to advanced stages and the presence of metastases in the body. This marker is a very important indicator that has high specificity, a study is used to determine the quality of the treatment, as well as the recurrence or screening of metastases. CA 15-3 analysis is also used to diagnose such a formidable disease of the mammary gland 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 may indicate the presence of cancer. In the diagnostic process, markers depend on tumor specificity and sensitivity. Specificity is the percentage of negative tumor markers in an analysis of a healthy person. Sensitivity is the percentage of a positive result obtained in patients with cancer. Today, not a single specific antigen has been found that directly and with a hundred percent probability could help make an oncological diagnosis. Tumor markers can be increased in inflammatory diseases of various nature, and will also increase in a benign process.
Normally, oncological 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 worsening environmental situation, the presence of bad habits or associated pathology.
How better
It is best to determine the tumor marker in dynamics, then it has more diagnostic value than a one-time diagnosis. The rate at which the increase occurs indicates the rate of tumor growth, as well as the presence of metastases. Even after the treatment, the CA 15-3 cancer antigen 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 breast cancer metastasis come to see a doctor with elevated rates; in 20% with a diagnosis of an oncological process, the marker also rises.
When to appoint
The blood is used as the material for the study, a CA 15-3 marker is given for the purpose of constant and timely monitoring, detection of early relapse, metastasis and the effectiveness of the treatment. Also, the differential diagnosis of the malignant process and mastopathy is not the least.
What is CA 15-3 (tumor marker)?
It is a high molecular weight mucin type glycoprotein and has a molecular weight of 300 kilodaltons.
Normally, the marker is part of the surface of the membrane of secreting cells. It can be detected with carcinoma of the mammary gland, but also 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 produce 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 by the liver, and it is its pathology, in particular cirrhosis, that can become an additional link in the diagnosis.
The importance of analysis
Breast cancer is a rather insidious disease, which in the early stages is difficult to diagnose. Taking a blood test CA 15-3 is also worthwhile for the purpose of prevention, then oncology has no chance at the earliest stage of the process. In addition, this will allow for timely diagnosis of liver pathology. Particular attention should be paid to the risk group, these are patients who have been treated, 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 an analysis of CA 15-3 for, is, as already mentioned, breast cancer, carcinoma, as well as metastasis of the process. Since it is a protein, and the main place of its metabolism is the liver, problems with it can also 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 Units per ml. It is also worth paying attention to additional methods for the study of the liver, especially 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 marker CA 15-3 is especially important for men. The dynamics of the analysis will allow us to judge the treatment and its quality.
Often, the marker rises and with a benign process, it is primarily the aforementioned diseases of the mammary glands. Autoimmune diseases can give elevated CA 15-3. The tumor marker can be increased even with such a physiological state of the woman’s body as pregnancy, especially in the third trimester, the indicator in this case is up to 50 U / ml.
What? Where? When?
You just need to
donate blood from a vein, which the nurse will take in the
treatment room. Only it is 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. The serum is examined, in which the indicator of the oncological protein is determined. The analysis takes three hours and the result is ready. An
oncologist, mammologist or gynecologist can prescribe an analysis. The study of blood serum is carried out using immunochemiluminescent analysis, and half an hour before the test is done, you should refrain from smoking.
From the moment of the last meal, at least 8 hours and no more than 14 must elapse. Blood is also donated before the medication is taken, and also not earlier than 1-2 weeks after the cessation of their intake. If it is impossible to refuse drugs, the direction should indicate which drugs the person is taking and in what dose. The day before taking the analysis, it is worthwhile to limit physical activity, as well as refuse fatty and fried foods.
Results
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 larger the tumor in the breast tissue. Metastasizes cancer, primarily in the bone and / or liver, as analysis may also indicate. 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 tissue simply does not produce this specific protein. In the case of a constant increase in concentration against the background of the treatment, you can safely think about its lack of effectiveness or, on the contrary, about the relapse of the process.
The 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 pathologies include autoimmune processes, tuberculosis, sarcoidosis. In the presence of this pathology, the result may be false positive.
In the diagnosis of breast cancer, an assay for CA 15-3 will be more valuable if a cancer-embryonic antigen is determined at the same time. And the test itself is best done a few weeks after the start of treatment.
Other analyzes
For diagnosis, you can donate not only blood, the material can also be pleural fluid, ascitic (especially for cirrhosis), cerebrospinal fluid, cystic (biopsy of a breast or ovarian cyst) fluid. In order to judge the pathology, it is necessary to focus on certain norms. In a healthy body, the tumor marker does not exceed 0 to 22 IU per milliliter, the border state should be considered from 22 to 30 IU per milliliter, an analysis in which 30 IU per milliliter or more is considered a pathology.
Prevention matters
Tumor markers are not the only research method that allows doctors to make the correct diagnosis. In the presence of oncology, markers will allow you to control the effectiveness of the treatment or to identify the disease at an early stage of its development. An analysis must be taken at least once a year, especially after 35-40 years.
Along with the definition of cancer 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 changes 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 intestine, liver, ovaries or uterus. The presence of this antigen in men indicates problems with the liver or gastrointestinal tract, in order to prevent the determination of CA 15-3, it is also necessary for them.
Only a specialist can help interpret the analysis, because an independent interpretation can lead to psychological disorders or stress, although an increase in markers can also be observed with a benign process. Assign an analysis can only be done by a specialist after conducting 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 we judge the final result.