Prostate test

What’s measured

What is PSA, or prostate specific antigen?

PSA, prostate-specific antigen, is a proteolytic enzyme produced by the epithelial cells lining the ducts of the prostate glands. Its role is to liquefy the ejaculate. A small fraction of PSA is secreted into the bloodstream, where it circulates in the free (10%) or bound form to A1AT (86% of total PSA) and A2MG. It is also present in the perinanal and paraurethral glands, in the bladder and in the mammary gland. It is only released into the bloodstream to an increased extent when the microstructure of the prostate tissue is disturbed, i.e. in various inflammations or tumours.

An important role of PSA is the liquefaction of the ejaculate. The elimination half-life is 1-3 days, in one day 50-80% of the original amount remains. Although screening of asymptomatic men is questionable because up to 80% of men with a total PSA above 4 mg/L do not have prostate cancer, the degree of elevated PSA concentration correlates with the size and condition of the tumor.

What is the PHI, or healthy prostate index?

The PHI (Healthy Prostate Index) is a derived mathematical algorithm that represents another modern method for detecting prostate cancer, especially in men aged 50 to 65 years with a total PSA level between 2.0 and 10.0 ug/l. The comprehensive prostate test includes the determination of PSA (prostate specific antigen), fPSA (free PSA - the free fraction of circulating PSA), fPSA/tPSA index (ratio of free PSA to total PSA), p2PSA (precursor form of free PSA).

It is released into the bloodstream at an increased rate only when the microstructure of the prostate tissue is disrupted. It is synthesised as an enzymatically inactive precursor, with the most clinically relevant form of free PSA being the precursor molecule p2PSA, which is used in diagnostics because it is more specific for prostate cancer. A small fraction of PSA circulates in the bloodstream in the free form, the larger fraction in the bound form. The free fraction of circulating PSA, fPSA, is an organ-specific marker. The absolute value of fPSA is not important for diagnosis, but the ratio to total PSA. The screening of asymptomatic (asymptomatic) men is a matter of professional debate because up to 80% of men with a total PSA above 4 ug/l are not diagnosed with prostate cancer, but only with benign prostatic hyperplasia (BPH). Nevertheless, in the case of carcinoma, the degree of increase in PSA concentration may correlate with the size and condition of the tumour.

Prostate screening is recommended for a positive family history of prostate cancer, suspected prostate disease, a mildly enlarged prostate, low to moderately elevated PSA levels, and is appropriate for men aged 50 to 65 years with a total PSA level between 2.0 and 10.0 ug/L.

During the prostate test, we also measure the levels of the following parameters
In addition to the PHI (Healthy Prostate Index) and PSA (Prostate Specific Antigen) tests mentioned above, we also measure the level of: 

fPSA

The fPSA test is recommended to differentiate prostate cancer from benign prostatic hyperplasia (BPH) at low to slightly elevated PSA levels. Men with prostate cancer with a normal or only slightly enlarged prostate have a lower percentage of free PSA than patients with BPH.

p2PSA

p2PSA is a proenzyme of prostate-specific antigen, a fraction of free PSA that circulates in the plasma. It enters the bloodstream and its quantity can be used to assess not only the presence of a tumor but also the risk of developing one. Since increased PSA production also exists in benign prostate disease, especially in common benign prostatic hyperplasia, a diagnosis based on PSA testing alone is not conclusive, and p2PSA refines the clinical significance of the determination.
To calculate the PHI (healthy prostate index), PSA, fPSA and p2PSA should be determined. If the PSA value is outside the range of 2 to 10 ug/l, the PHI cannot be calculated.

When to have Prostate test (PSA+PHI)

• During a preventive checkup
• With a positive family history of prostate cancer
• When prostate cancer is suspected
• For prostate cancer to determine clinical stage and prognosis
• To monitor treatment and possibly detect recurrence

Instructions before collection

We do not recommend entry of patients/clients with clinical signs of disease (temperature, cough, signs of respiratory tract infection, etc.) to undergo this test.
We recommend hand disinfection prior to entry to the clinics/collection points.

It is advised to fast for a minimum of 8 hours by refraining from eating or drinking anything expect water. Faiing to fast before the test may affect result quality. If you are currently on medications, consult your healtcare provider to determine whether you should continue taking them prior to the test.

PREPARATION FOR BLOOD COLLECTION
The recommended time to collect blood is between 7 a.m. and 9 a.m., to obtain comparable results from different blood draws. To assess the numerical test result, so-called reference intervals are used, which are based on morning fasting collections and are used for population comparison. This time interval is also recommended in light of the biological cycles that naturally take place in the body.

GENERAL PRE-SAMPLING INSTRUCTIONS
It is necessary to come to the testing site earlier, so that you can rest in the waiting room for approximately 20 minutes to have a relatively relaxed body and mind.
It is necessary to arrive on an empty stomach for the collection itself, in the case of collections at a later time in the day, at least three hours on an empty stomach. At home, it is desirable to drink a sufficient amount of pure water (at least up to half a liter) - this is important for a successful blood collection. Mineral water, juice, coffee and tea are not recommended.
Herbs included in tea may contain substances affecting the blood count. Coffee and black tea increase gastric acid production and release insulin from the pancreas, thereby affecting glucose metabolism. Since everything in the body is interrelated, they can impact other tests. Another extreme is when your body is running out of fluids. In this case, the number of red blood cells, the level of protein and lipids bound to the protein increase and the level of urea in the blood can also increase. It is therefore advisable to drink pure water when you wake up.

Generally, it is recommended to:
• around 6 p.m. eat only light meals, do not eat fatty food (cheese, butter, cream, meat, smoked meat, bacon) and sweet meals,
• fast for 10-12 hours (Attention: it is not advisable to starve for more than 16 hours!), in the case of later collection (after 9:30 a.m.), a lighter breakfast is allowed, no later than 3 hours before collection,
• drink non-alcoholic beverages and drinks without sugar in the usual quantity, in the case of adult clients 24 hours before blood collection (Alcohol in the blood changes lipid levels, the level of glucose is reduced, uric acid levels increase and liver enzymes are released into the blood),
• take only prescribed medicines in the evening,
• avoid increased physical activity, and strength and endurance exercise the day before blood collection (Lipid, glucose, some enzyme levels in the blood and other parameters may change during physical activity. The recovery of normal values to maintain the accuracy of laboratory results may take a longer time, depending on the duration of the exercise, your physical fitness in general and other factors. We recommend maintaining normal daily physical activity such as light stretching, short cycling to work, gardening, etc.),
• avoid psychological stress, which raises blood glucose levels and causes the release of stress hormones in particular,
• avoid smoking for at least 6 hours prior to blood collection because it increases the level of carbonylhemoglobin produced by the reaction of the blood dye with carbon monoxide and alters the permeability and elasticity of the vessels, affecting the ratios of blood analytes,
• do not chew gum for at least 6 hours before blood collection, as this may affect glucose and enzyme levels,
• do not undergo stressful diagnostic or therapeutic interventions for at least 24 hours prior to blood collection.
If any of the tests you have selected require special preparation, you will be informed of the fact by email with the order and blood collection instructions attached. These specific instructions have priority over the general recommendations for preparation.

MEDICINES
It is recommended to have blood collected before the planned doses of medicines. If it is not possible to take the medicine later, you should inform the nurse during blood collection and specify what medication you have taken.
Take the medicines prescribed by your doctor in the morning or bring them with you to take them after blood collection (thyroid medicines, antihypertensive medicines, blood thinners, contraceptives, etc.) In the case of later collection (after 9:30 a.m.), you can take the prescribed medication in the morning.
Do not take iron, vitamin, nutritional supplements or other supplements, including homeopathics, for at least three (3) days prior to blood collection.

SPECIFIC SITUATIONS
In order to obtain the appropriate answers to your questions with regard to the laboratory tests, it is important to accurately notify the nurse at the healthcare provider about the following facts prior to your blood test:
• regularly used medicines and supplements (ideally come with a written list to the blood collection site),
infectious diseases you suffer from (e.g., HIV, hepatitis, mononucleosis...),
• contact with an infected person or presence in an infectious environment,
• if you have received an infusion within the last 5 days, specify into which limb,
• intramuscular injections within 3 days prior to the blood collection date,
• long-term immobilisation, lost ability to move,
• activities at higher altitudes,
• allergy to common band-aids,
• if you feel unwell when looking at blood or needles, please also notify our blood collection staff of the fact.

OTHER FACTORS
Please note that prolonged use of medication or other important factors may affect the values measured by the tests you have selected. For more information, please see the description of the specific test. To obtain objective test results, take the time to properly prepare for your blood collection.

Results

It is important to stress that if you have an elevated or decreased PSA level, you should always contact your urologist or general practitioner and consult the results with your GP. If you have made an appointment for this test yourself and it has not been recommended by your doctor, please be aware that the decision to have this test is your responsibility and Unilabs cannot give you specific advice on whether it is suitable for you.