Prostate cancer occupies an “honorable” third place in mortality among other oncological diseases, and is a leader in the group of elderly men. In Russia alone, about 14,000 cases of this disease are registered each year. PSA analysis helps to diagnose it in time and take measures in time. What is it and how to prepare for it so that the results are correct?
What does PSA abbreviation mean?
PSA or PSA is a prostatic specific agent. In its structure, it is a protein polypeptide consisting of more than 200 amino acids. This substance is produced by both sick and healthy prostate cells, therefore, a small presence in the blood shows each PSA analysis. The norm for each age category of males is different, since with age, a specific prostatic agent is produced in large quantities. In healthy men, it is present, in addition to blood, in the ejaculate (semen) and in the secretion of the prostate. If there are tumor cells in the prostate gland, the prostate agent begins to be produced in significant volumes, 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 patients who have already been treated or are being treated with cancer or prostate adenoma.
Age norms
Prostate cancer is a very insidious disease. If it is detected at the wrong time and treatment is delayed, it will inevitably lead to death. According to medical statistics, this type of cancer is not associated with smoking, alcoholism, sexual activity and sexually transmitted diseases, that is, every man can get sick with it. The only way to detect this ailment in time and thereby save your life is a PSA blood test. The norm can be exceeded temporarily, which is associated with some diseases. In such cases, the analysis is repeated or additional studies are performed.
PSA age standards| Age (years) | units measuring | PSA indicator |
| 40-49 | ng / ml | 2,5 |
| 50-59 | ng / ml | 3,5 |
| 60-69 | ng / ml | 4,5 |
| 70 and above | ng / ml | 6.5 |
What is the gray zone?
For research, blood is taken from a vein. The results of the analysis, when the values of the prostatic agent are higher than normal, but do not exceed 10 ng / ml, are usually called the "gray zone". In such cases, the doctor may prescribe a prostate biopsy. The main indication for its implementation is the ratio of the so-called free PSA to the total. It in healthy men should be above 15%. The so-called PSA free analysis is a determination of the amount of unbound (free) proteins of the prostatic agent contained in blood serum. The fact is that only about 10 percent of all forms of the prostatic agent are present in this condition. 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 undetectable. Laboratory studies show only the amount of free and associated with α-1-antichymotrypsin prostatic agent. Their total value is demonstrated by the so-called total PSA blood test . If a man has prostate cancer, in the body α-1-antichymotrypsin begins to be produced in large quantities, which leads to more binding of the agent and a decrease in its free form. Consequently, the percentage of these two forms decreases.
What is the reason for exceeding the norm?
Some diseases have a great influence on the PSA quantitative indicator in blood serum samples.
The most dangerous of them is
prostate cancer, that is, a malignant enlargement of the prostate that is not associated with age and gives metastases. At the slightest suspicion of cancer, manifested in pain during urination, sensations as if the bladder is not completely empty, frequent urge and difficulty urinating, as well as pain in the perineum, an analysis of PSA is necessary. The norm is typical for healthy people, but the level can be elevated with the following diseases:
- adenoma (a benign tumor that does not metastasize);
- inflammation of the prostate;
- 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 amount of prostatic agent in the blood is influenced by several factors. Therefore, in order to get a reliable PSA analysis, preparation for it must be carried out very seriously.
Exceeding the norm 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 indication:
- Times of Day;
- insertion of a catheter into the bladder and cystoscopy;
- rectal (using fingers) examination of the prostate gland.
Analysis preparation
Each patient is required to know and strictly observe the requirements of preparation before doing a PSA analysis. Its norm for different ages is well known. The level may not be increased due to prostate pathology, but due to non-compliance with special conditions.
They are as follows:
- abstinence from ejaculation for at least 2 days before analysis;
- to analyze no earlier than 3 days after deep massage of the prostate;
- if the patient is undergoing TRUS, at least 7 days should elapse after the procedure before PSA analysis;
- after a biopsy of the prostate, which greatly increases the amount of agent in the blood, at least 6 weeks must pass before analysis;
- if the patient underwent a transurethral resection, PSA analysis is allowed to be performed no earlier than 6 months after the operation.
In addition, before analysis it is advisable to refrain from smoking, not to eat fatty foods for more than a day, to avoid excessive physical and mental stress.
When is the test prescribed?
If you suspect a prostate disease and during the treatment of detected tumors, a PSA analysis is prescribed. The norm for those being treated depends on the type of therapy. So, after surgical removal of the prostate (laparoscopic prostatectomy), the digital indicator of the specific prostatic agent, as a rule, decreases to 0.2 ng / ml, and after radiation therapy - 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 PSA level rises, we can state the further development of the tumor process. However, exceeding the PSA norm does not always indicate cancer. 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 seeps into the blood more easily, and, as a result, its amount is somewhat overestimated.
What measurements are made to clarify the diagnosis?
As noted above, with age, each man's prostate gland increases. To reduce the effect of this natural increase on test results, 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 division is higher than 0.15 ng / ml / cm3 cubic, there is a suspicion of the onset of pathological changes in the prostate gland. In such cases, a person undergoes a biopsy. Another type of study is to determine how fast PSA is changing. If the indicator is higher than 0.75 ng / ml / year, the patient has a very high probability of developing a tumor. The analysis data help with sufficient accuracy to determine the presence of metastasis in the patient. So, with indications of a prostatic specific agent above 50 ng / ml, there is a high probability of the onset of the metastasis process. And numbers above 100 ng / mg indicate the presence of deep metastases.