There are no specific urination disorders in prostate cancer. Various tests are used in clinical practice to detect it. They can not only point to this diagnosis, but also determine the stage of development of the disease. The most common blood test is a blood test to measure the value of the prostate-specific antigen /PSA/ and a rectal swab /PT/.
The PSA value itself cannot serve as a diagnosis of prostate cancer. It is specific to the prostate as an organ and may also be elevated in benign prostatic hyperplasia and inflammation of the prostate /prostatitis/. The blood test shows both the value of the total PSA and the free PSA in the blood. In older editions of the European recommendations, it was recommended to measure the ratio of free to total PSA and, based on the obtained value, to direct further studies to prove prostate cancer. Now, PSA density is used for this purpose. Elevated PSA values do not definitely indicate the presence of prostate cancer. They only direct the clinician to further studies in this direction.
Rectal prostate examination is a subjective method of prostate examination. Much depends on the experience of the urologist. A common finding is the finding of a node or a hard area on the surface of the prostate, and only in cases where the disease develops peripherally of the prostate gland. When developing in the central areas, such a node cannot be felt. Together with the elevated PSA value and the finding of such an area in the prostate, there are grounds for continuing the diagnostic process by switching to prostate imaging studies. First of all, this is multiparametric nuclear magnetic resonance with contrast material of the pelvis and prostate.
With this method, suspicious areas in the prostate that are suspected of a malignant process are visualized. In the presence of 4 and 5 points according to the PI-RADS system /American system for evaluating the tissue characteristics of the prostate, introduced in 2012/, a prostate biopsy is recommended. Currently, transperineal prostate biopsy is increasingly used in clinical practice instead of transrectal.
The main advantage of the transperineal so-called fusion biopsy is the ability to take tissue from suspicious areas much more accurately and specifically and send it to the pathologist. Another advantage is the use of equipment that can transfer the MRI image to ultrasound equipment, under whose visual control tissues are taken from 18-20 places in the prostate. And last but not least is the fact that the rectum is not passed through, as was the case with the transrectal biopsy, thus avoiding the possibility of inflammatory complications and bleeding from the anus. Of course, in a locally advanced process with cartilage density of the prostate, this biopsy method is not applied, but the transrectal one with fewer stitches for taking material is used.
And here sometimes the contradictions begin. With none of the described methods alone or in combination, the desired diagnosis cannot be proven 100%. Why this is so will become clear later. According to NCCN /network of cancer organizations from the USA/ in men aged 40 with a PSA value above 2.5 ng/ml there is a high suspicion of prostate cancer, as well as in men aged 60 with a PSA value of 4.5 ng/ml and above. PSA values above 10 ng/ml are suspicious for cancer in all age groups.
In these cases, a negative rectal smear has no particular diagnostic value and is passed directly to MRI of the small pelvis and prostate. According to the recommendations of the European Urological Association /EAU/, PSA values suspicious for prostate cancer are above 1 ng/ml in men aged 40 and 1-2 ng/ml in men up to 60 years. The usual practice is to test PSA from 50 years onwards. To exhaust the possibilities of PSA, density measurement is applied. This is a method in which the PSA value is divided by the prostate volume. The higher the obtained value above 0.15-0.20 ng/ml, the greater the probability of prostate cancer.
The European Association recommends a lower threshold of 0.15 ng/ml, and cases with PSA density below 0.09 ng/ml have a risk of prostate cancer below 4%. PSA density is currently a sufficiently reliable prognostic criterion for switching to multiparametric MRI and subsequent biopsy. Here, contradictions may arise regarding prostate volume measurement and hence false-negative results for PSA density. Determining prostate volume by PT is quite subjective. The use of ultrasound depends on the capabilities of the ultrasound device - whether it is a completely new generation or from 10 years ago. The experience of the imaging technician is also important.
And last but not least, MRI is used in the context of a method for determining "areas of interest" in the prostate with a view to subsequent prostate biopsy. The use of a scanner and other imaging methods, other than those mentioned above, is not convincing enough. The use of the ratio of free to total PSA remains in the background, and recently it has not been used so often.
The main method for diagnosing prostate cancer is prostate biopsy. In recent years, preference has been given to transperineal biopsy /fusion/ biopsy due to a lower risk of inflammatory complications and more precise sampling of material from the prostate. The MRI image is used, which is superimposed on ultrasound equipment and is performed between 18-22 stitches from the prostate gland. Each tissue material is sent separately to the pathologist for an opinion. This completes the diagnostic process, and the results can be:
1. Presence of prostate carcinoma /limited to the prostate or extending beyond the organ/
2. Benign prostatic hyperplasia /BPH/, no carcinoma
A certain conditionality must be taken into account with respect to each diagnostic unit, starting with the determination of PSA and density, the guiding multiparametric MRI and, last but not least, the interpretation of the histological preparations. From there, the unraveling of each clinical case begins with the determination of the stage of the disease and the corresponding treatment. A normal practice in recent years and in our country is to seek a second opinion, especially when it comes to the MRI finding and the quality of the transrectal biopsy performed versus the fusion biopsy. Not all urological centers are equipped with fusion biopsy equipment, such centers are found in large university hospitals and, exceptionally, other multi-profile ones. And while there are a sufficient number of specialists to perform such a biopsy, pathologists with sufficient experience in the diagnosis of this disease are extremely insufficient. Finally, let us recall the Latin postulate that “qui bene diagnoscit bene curat” /who diagnoses well and treats well/.
Prof. Krasimir NEIKOV, Urological Clinic, USBALO “Ivan Chernozemski”, Sofia