PSA analysis is the norm. How to take a blood test for PSA, correct preparation

Prostate cancer holds the "honorable" third place in mortality among other cancers, and in the elderly men's group is the leader. Only in Russia every year about 14,000 cases of this disease are registered. In time, it is possible to diagnose it and take timely measures to help analyze PSA. What is it and how to prepare for it so that the results are correct?

What does the abbreviation PSA mean?

PSA or PSA is a prostate specific agent. By its structure, it is a protein polypeptide consisting of more than 200 amino acids. Produce this substance and patients, and healthy prostate cells, so a small amount of it in the blood shows each PSA analysis. The norm for each age group of males is different, since with age the prostatic specific agent is produced in a larger amount. In healthy men, it is present, in addition to blood, in the ejaculate (sperm) and in the secretion of the prostate. In the presence of tumor cells in the prostate gland, the prostate agent begins to be produced in significant amounts, which is used in error-free labeling of the disease. In addition to diagnosing the disease, the analysis is performed to monitor the health status of already treated or treated patients with prostate cancer or adenoma.

Age norms

Prostate cancer is a very insidious disease. If it is not found at the right time and start treatment late, it inevitably leads to a fatal outcome. As shown by medical statistics, this type of cancer is not associated with smoking, alcoholism, the intensity of sexual activity and sexually transmitted diseases, that is, every man can get sick of them. The only way to find this disease on time and thus save your life is to analyze the blood of PSA. The norm can be exceeded temporarily, which is associated with certain diseases. In such cases, the analysis is repeated or additional studies are carried out.

What is the "gray zone"?

For the study, blood is taken from the vein. The results of the analysis, when the values of the prostatic agent is above the norm, but do not exceed 10 ng / ml, is usually called the "gray zone". In such cases, the doctor may prescribe a prostate biopsy. The main indication for its conduct is the ratio of the so-called free PSA to the total. It should be higher than 15% in healthy men. The so-called PSA free test is the determination of the number of unbound (free) proteins of the prostatic agent contained in the serum. The fact is that only about 10 percent of all forms of the prostatic agent are present in this state. The remaining 90 percent is associated with either α-1-antichymotrypsin (a protease inhibitor) or α-2-macroglobulin (an inhibitor of pepsin, plasmin and other enzymes). Being in conjunction with α-2-macroglobulin, PSA is practically not determined. Laboratory studies show only the amount of free and α-1-antichymotrypsin-associated prostatic agent. Their total value is demonstrated by the so-called PSA total blood test . If a man has prostate cancer, α-1-antichymotrypsin begins to be produced in large amounts in the body, which leads to more binding of the agent and a decrease in its free form. Consequently, the percentage ratio of these two forms decreases.

What is the reason for exceeding the norm?

The quantitative index of PSA in serum samples is strongly influenced by certain diseases. The most dangerous of these is prostate cancer, that is, a malignant enlargement of the prostate that is not related to age and gives metastases. At the slightest suspicion of cancer, manifested in soreness with urination, sensations like a bladder is not completely emptied, frequent urges and difficulties with urination, and pain in the perineum, it is necessary to make an analysis of PSA. The norm is typical for healthy people, the elevated level can be with the following diseases:

- Adenoma (benign tumor that does not give metastasis);

- inflammation of the prostate;

- a heart attack (necrosis due to spasm);

- ischemia (anemia of the prostate, associated with problems in the blood vessels);

Acute renal failure.

What factors cause an increase in the prostatic agent?

The number of prostatic agents in the blood is affected by several factors. Therefore, in order to obtain reliable PSA analysis, preparation for it should be carried out very seriously. Abnormality is affected by:

- ejaculation;

- Deep prostate massage;

- biopsy;

- TRUS (specific ultrasound of the prostate gland);

- TURP (surgical treatment of the prostate).

Factors that do not affect the readings:

- Times of Day;

- insertion of a catheter into the bladder and cystoscopy;

- rectal (with the help of fingers) examination of the prostate.

Preparation for analysis

Every patient is obliged to know and strictly follow the training requirements before doing a PSA analysis. His norm for different ages is well known. The level can be increased not because of the pathology of the prostate, but because of non-compliance with special conditions. They are as follows:

- abstinence from ejaculation for at least 2 days before the analysis;

- to carry out the analysis not earlier than 3 days after a deep prostate massage;

- if the patient is performing TRUS, after the procedure before the PSA analysis should be at least 7 days;

- after biopsy of the prostate, which greatly increases the amount of the agent in the blood, should pass at least 6 weeks before the analysis;

- if a patient underwent transurethral resection, PSA analysis can be performed no earlier than 6 months after the operation.

In addition, before the analysis it is desirable to refrain from smoking, do not eat fatty foods for more than a day, avoid excessive physical and mental stress.

When is the analysis scheduled?

If suspected of prostate disease and in the treatment of detected tumors, PSA is prescribed. The norm in the treatment depends on the type of therapy. So, after surgical removal of the prostate (laparoscopic prostatectomy), the digital index of the prostatic specific agent is usually reduced to 0.2 ng / ml, and after radiotherapy - up to 1 ng / ml. These indicators are very favorable and allow us to hope for a long period without relapse. If, after all types of therapy, the level of PSA increases, we can ascertain the further development of the tumor process. However, excess PSA does not always indicate a cancer disease. In rare cases, the result is influenced by the individual characteristic of the patient's tissue barriers. There are people whose tissues have increased permeability, so the prostatic agent is easier to seep into the blood, and, as a consequence, its amount is somewhat overstated.

What measurements are taken to clarify the diagnosis?

As already noted above, with age in each man the prostate gland increases. To reduce the effect of this natural increase on the results of the analyzes, the PSA density is measured. This indicator is determined by dividing the quantitative indicator by the measured volume of the prostate. If the quotient obtained by fission is greater than 0.15 ng / ml / cm cubic, there is a suspicion of the onset of pathological changes in the prostate gland. In such cases, a person is biopsy. Another type of study is to determine how fast the PSA changes. If the index is higher than 0.75 ng / ml / year, the patient has a very high likelihood of developing a tumor. The data of the analysis help to determine with sufficient accuracy the presence of metastases in the patient. Thus, with a prostate specific agent above 50 ng / ml, there is a high probability of initiating the metastasis process. And figures above 100 ng / mg detect the presence of deep metastases.