If the PSA value in the blood rises above the defined limit (which is determined according to the age and size of the prostate!), additional prostate examination is recommended, especially rectal examination, ultrasound, magnetic resonance imaging of the prostate, and/or prostate biopsy.
The upper limit of PSA has been proposed to be 2.5 ng/mL for men aged 40–49 years, 3.5 ng/mL for men aged 50–59 years, 4.5 ng/mL for men aged 60–69 years and 6.5 ng/mL for men aged 70 years and above.*
Prostate-specific antigen (PSA) is currently the most clinically significant indicator (marker) of prostate cancer. It is an enzyme produced by both normal and cancerous prostate cells, and testing its concentration in the blood is a commonly used method in the diagnosis of prostate cancer. PSA stands for a protein produced by the prostate gland.
The basic function of the PSA protein is to liquefy sperm, so its greatest concentration is in the semen and only a small part is released into the blood. So every man with a prostate has a certain level of PSA. If the structure of the cells and glands of the prostate is damaged (for example, due to a prostate tumour), PSA enters the blood in a higher amount.
A blood test to determine the PSA level is not only performed in men with symptoms of prostate cancer (such as difficulty urinating, erectile problems, pelvic and back pain, etc.), but also in men without symptoms as a preventive examination. The success of the treatment of malignant tumours is almost always dependent on early recognition of the malignant tumour and accurate diagnosis.
An increased level of total PSA in the serum can be observed in prostate cancer, but also in other diseases, e.g. benign prostatic hyperplasia, prostatitis, acute urinary retention or after some urological manipulations. It also appears after sexual intercourse. Unfortunately, some types of prostate cancer may not have any effect on the PSA level in the blood. Therefore, rectal examination is also necessary.
** The PSA value is dependent on age and prostate size, so there is a slightly different “normal” PSA level for each individual man. Under normal circumstances, the serum PSA level is below 4 ng/mL, a value that is internationally recognised as the dividing line between normal and elevated PSA. Difficulties in diagnosing prostate cancer through PSA measurement are caused by the fact that up to 20% of cancer patients have a PSA level below 4 ng/ml, and conversely, not every patient with a PSA between 4 and 10 ng/ml has prostate cancer. We are talking about the “diagnostic grey zone”, in which cancer occurs in only 25% of patients.
