Another method for determining cancer in modern medicine is the diagnosis of gastric and intestinal cancer markers. Oncomarker is a special protein present in the blood or urine of a cancer patient, produced by cancer cells from the time of their formation, which helps to diagnose cancer at an early stage. Since it indicates the presence of a tumor, sometimes the name is called tumor markers. Based on the deviations of cancer markers from the norm, the doctor can make a picture of the changes in the therapy process, and depending on this, judge about the correctness of the choice of the treatment strategy.
As of today, about two hundred of them are known, but only a tenth of them are of practical interest.
Tumor markers are divided into several classes:
- immunological - antigens inherent in tumors and antibodies to them;
- exchange products;
- plasma proteins;
- protein decay products of neoplasms.
Each onkomarker corresponds to a disease, or a number of diseases, and sometimes, sometimes, it is impossible to say with certainty which disease caused an increase in the level of indicators. To clarify the diagnosis, evaluation is based on analyzes of the data set. For example, increased levels of alpha-fetoprotein( AFP) are typical for breast cancer, but CA 125 and CA 15-3 can also testify to this.
As the article in this article is about stomach cancer, let us dwell in more detail on what makes it possible to identify this disease.
Oncomarkers of the stomach
To gastric include cancer-embryonic antigen( CEA), cancer antigens CA 19-9 and CA 72-4.Usually a comprehensive analysis is carried out, including all three indicators.
Cancer-embryonic antigen( REA) is produced at the embryo stage, and after birth, its production ceases, and the level of CEA rapidly decreases. In the blood of an adult this antigen is practically absent. Increasing the level is a sign of the presence of some kind of tumor in the body. The norm of CEA is 5 ng / ml. To perform this analysis, venous blood sampling is required, and the patient should refrain from eating for 8 hours before blood donation and not smoking during the day.
CA 19-9 antigen is produced in the pancreas and liver. The norm of this oncomarker is the value of up to 37 units / ml. If the value exceeds this threshold during the analysis, it is worth further testing using other methods. However, you should know that 7-10% of people do not develop this antigen genetically, so even if they have a tumor, they will not give an antigen signal.
The gastric cancer marker CA 72-4 is produced by cancer cells, and therefore its presence in the blood indicates the formation of tumors. The norm of the gastric cancer marker CA 72-4 is 2-4 U / ml. The gastric cancer marker CA 72-4 is also used to assess a patient's chances of survival. The dependence of chances is inverse, that is, the higher the marker index, the less the patient's chances. However, it is worth remembering that not always an elevated indicator is a sign of stomach cancer, it can grow in other diseases, for example, liver cirrhosis, pneumonia, acute pancreatitis.
Thus, the diagnosis based on oncomarkers also does not allow one hundred percent diagnosis, but only presupposes the presence of a disease. That is why a set of studies is used for diagnosis, starting with a clinical blood test, and ending with research methods using special devices, for example, ultrasound, x-ray, MRI, and others.