Blood test for PSA: norms and transcript
PSA - the full name of this oncomarker - a prostatic specific antigen, in its structure is a two-component protein( glycoprotein).Isolated epithelial cells of the prostate gland and in the composition of its juice enters the seminal fluid.Its main function is dilution of sperm to provide functional mobility of spermatozoa.Table of contents: Free and general PSA in the diagnosis of diseases Rules for the preparation of a patient for the analysis of blood on the PSA Analysis of the total prostatic specific antigen( PSA) Analysis of free prostate specific antigen PSA General recommendations and remarks
General PSA: its significance in the diagnosis of diseases
In the blood, the following are isolated:
- total PSA;
- free PSA;
- bound PSA.
The amount of bound and free equals the total PSA.The free form normally takes about 20% of the total PSA.
The diagnostic value is mainly the total PSA level, the value of which increases depending on the growth of the prostate.
The method is the most specific for the identification of prostate cancer.Appointed with existing disorders of urination, especially - night( nocturia).
It is used in conjunction with finger research, ultrasound.
Please note: is determined by PSA after prostate irritation and after rectal suppository application not earlier than a week after these procedures.Since they can distort a reliable result.
An even longer period should be maintained after:
- Prostate biopsy techniques;
- removal( resection) of the prostate;
- mechanical massage.
Important: , both general and free PSA, must be taken and determined from one taken "portion" of blood, using one method.You need to do the analysis only in one laboratory.
Blood is collected in the morning, before eating.For blood sampling, the elbow of the elbow is used.
Rules for the preparation of a patient for blood analysis for PSA
The last meal should be at least 12 hours before blood collection.You can drink only ordinary water, no other drinks, especially containing caffeine, can not drink.Categorically contraindicated alcohol.
Two days before the study, the patient should follow a diet that excludes fried, smoked, fatty, too salty.If possible, refrain from meat products.For the adoption of food recommended boiled vegetables, neutral in acidity of fruit.You can cook lean vegetable soups and cereals.
For several days it is worth to refrain from playing sports loads, hard physical work, cycling is not recommended.Also it is necessary to refuse sexual activity.
Analysis of the total prostatic specific antigen( PSA)
General PSA is a tissue prostatic protein that forms part of the excretory excretory prostate.In medicine, it is a marker of tumor diseases.
In what cases is an assay for the determination of total PSA values:
- diagnosis of prostatic adenoma;
- control of adenoma treatment;
- diagnosis of prostate cancer, especially early detection of a tumor;
- monitoring the treatment of an already diagnosed malignant neoplasm of the prostate.
Normally, the total PSA in the blood ranges from 0-4 ng / ml.But about the norms there are different opinions.Recently, a number of researchers have been limited to 2 ng / ml.
In what cases are the increased indicators of total PSA determined:
- at all stages of prostate adenoma development;
- after surgery for the removal of prostatic adenoma;
- after the ejaculation occurred on the eve of the analysis;
- in case of problems with potency;
- for various forms of violation of the act of urination;
- after a long ride on a bicycle, especially on a jolting road.
Note: if the PSA( total) values exceed 30 ng / ml, this fact should be regarded as a case of a possible developing oncological process .
In advanced stages of cancer, with the metastasis available, the total PSA values can reach 1000 ng / ml and above.
Free prostatic specific antigen is part of the total PSA and is also a product of the physiological activity of the prostate.
Note: the greater the age, the higher the rate of this antigen.
In any case, its level should not exceed 4 ng / ml.
The data of this marker should be determined for signs of prostate cancer.
In addition to the very index of free PSA in urological-andrological practice, the determination of the percentage of free PSA to total PSA is applied.The value is expressed in percentage terms.
The figures for this relationship become particularly important if the PSA is already above the norm, but does not rise to critical levels and is between 4.0 and 10.0 ng / ml.
In this case, if the ratio of free PSA / total PSA does not rise above 15%, benign growth may be suspected.If, in the process of dynamic monitoring of the level of this indicator, its gradual increase is noted, then one can draw conclusions about possible malignancy of the process, as well as a small effect of both conservative and surgical measures.
If, on the background of the treatment being performed, the level of the ratio decreases, then one can draw conclusions about the beneficial effect of the therapeutic process.
Normal is the free PSA value less than 0.93 ng / mL .
Indications for free PSA:
- Dynamic monitoring and control of patients with established malignancy of the prostate;
- dynamic observation and monitoring of patients with a diagnosis - "prostate adenoma" with the main purpose of early diagnosis of possible malignancy of the process;
- differential diagnosis of cancer, adenoma and prostatitis;
- as a prophylactic analysis in men over the age of 50 years.
When is the concentration of free PSA increased:
- with existing prostatic adenoma at different stages of the disease;
- inflammatory-proliferative processes of prostate tissue( prostatitis);
- Malignant pathology of the prostate;
- early terms of the postoperative period in the surgical treatment of the prostate;
- ejaculation( ejaculation) a few hours before the test.
In prostate cancer, the level of free PSA is much lower than in benign hyperplastic processes and inflammatory diseases.
The PSA free / PSA common ratio is predictive:
- if the indicator is less than 15%, it indicates serious problems and is unfavorable in terms of prognosis;
- if the indicator is within 15-70% then the forecast is favorable.
General recommendations and remarks
The health status in most cases depends on the person himself.To determine the developing malignant process in the early stages it is necessary to periodically undergo preventive examinations.
For this reason, men, after reaching the age of 50 years, and in some cases even earlier( with the existing pathology of the prostate), it is necessary to take PSA analysis at least once a year.
When detecting indicators of analysis beyond the norm should be seen andrologist, urologist, or oncologist, and undergo a thorough examination for the purpose of early diagnosis of a possible disease.
Note: does not in all cases of output of digits of analysis beyond the limits of the norms there is a pathological process.
Detection of a malignant disease at an early stage allows almost 100% of cases to be cured of it.
For more information on the method of blood test for PSA and other oncomarkers, and about the effectiveness of these tests, you will receive a video review:
Alexander Lotin, medical reviewer