Evaluation of the Activity of Prostate Cancer Biomarkers in Post-massage Urine

Abstract

Prostate cancer (PC) – refers to important and serious problems in urology. In Ukraine, PC ranks fourth in the structure of malignant neoplasms and third in the structure of mortality of men over 60 years. An important issue in the systemic approach to improving the quality of health care to ensure life expectancy while maintaining activity in men is not only the search for new highly sensitive, specific and non-invasive diagnostic methods that will detect PC in the early stages of the disease, but also the need to review and justify new threshold values of already known biomarkers, and the ability to find their optimal combinations. Many studies have shown that the detection of sarcosine by high performance liquid chromatography in combination with electrochemical analysis of the element has made it possible to prove the limit of detection of sarcosine in the urine of cancer patients. Imperfect study and limited use in clinical practice of prognostic features of acid phosphatase (PCP), citrate, zinc, sarcosine, spermine and myoinositol as biomarkers in post-massage urine prompted this kind of study.

The objective: to evaluate the activity of acid phosphatase, citrate, zinc, sarcosin, spermine and monoinositol in postmassage urine as biomarkers of prostate cancer.

Materials and methods. During the period 2016–2020, 246 men, aged 45 to 84, were examined on the basis of the Institute of Urology of the National Academy of Medical Sciences of Ukraine with complaints of urination disorders who were hospitalized or underwent a comprehensive examination. All patients received written consent to participate in the study, which was approved by the Ethics ComMission in the Institute of Urology of the National Academy of Medical Sciences of Ukraine. All PC patients underwent 12-point prostate biopsy under TRUS control using a G18 biopsy needle. During pathomorphological examination PC was classified according to Gleason’s score. Patients were divided as follows: with verified PC (1st group), patients with benign prostatic hyperplasia (BPH) (2nd group) and relatively healthy (3rd group). The content of PC biomarkers in post-massage urine was determined by known methods. Thus, acid phosphatase (EC 3.1.3.2) was analyzed by reaction with 1 mM para-nitrophenyl phosphate in 0.1 M flow buffer, pH 6.2; determination of citrate – ultraviolet; sarcosine – enzyme-linked colorimetric study and spermine – measurement of the amount of quinone-imine dye based on the formation of hydrogen peroxide; spermidine – by accumulation of l-pyrroline. All these methods were performed on a spectrophotometer «Specoll-211» (Germany). Zinc was determined by atomic absorption spectroscopy on an Analytik Jena ContrAA 300 spectrophotometer (Germany). Myoinositol was evaluated by the enzymatic cyclic method and measured by increasing the optical density of thio-NADH at 405 nm with an incubation of 37 °C.

Results. Among the 246 patients studied after the examination, 107 (43.5%) had verified PC, 62 (58.0%) of which had a non-aggressive and 45 (42.0%) had aggressive form; 71 (28.9%) were diagnosed with BPH and 68 (27.6%) were found to be relatively healthy and included in the reference group. PAP data indicate that in almost healthy values of the indicator was the highest compared to those found in patients with BPH and PC, the lowest values were found in cases of PC, when its median was 1.5 IU/l. There is no evidence of a difference between the levels of PAP activity in patients with PC in the clinical stage T1-T2 and stages T3b. The use of PAP for the differential diagnosis of indolent and aggressive malignancies has not shown clinically significant results. In men without signs of prostate pathology, the concentration of citrate in post-massage urine, in contrast to patients with BPH, significant increased, and in patients with PC showed the opposite trend. Quantitative content of citrate in prostatic urine in the case of non-aggressive indolent tumors (Gleason index 5–6) significantly exceeded the value of the indicator in aggressive (Gleason 7–9 points) The concentration of zinc in prostatic urine in normal prostate and BPH almost did not differ. With increasing proliferation, especially under conditions of accelerated uncontrolled cell growth, apoptogenic function of zinc is first inhibited and then disappears at all, as a result of the comparison of zinc content in post-massage urine in patients with PC and in cases of pathology, its values, however, could not be established between patients with indolent and aggressive tumors. In terms of sarcosine content, patients without signs of prostate pathology and BPH did not differ statistically, while patients with PC in all parameters significantly exceeded the previous two groups. The median concentration of myoinositol in the functionally normal prostate was 35 mM, in patients with BPH there was a slight increase to 38 mM, and in PC the median value was 3 and 3.5 times smaller. In the absence of signs of prostate pathology, the concentration of spermine was 87 mM, in BPH the median increased to 114 mM, managed to identify significant differences. However, it was possible to trace the value of spermine content in determining the stage of the tumor process, namely between T1c – T2 and T3a.

Conclusion. Enzymatic activity of acid phosphatase allows to detect PC but makes it impossible to make a differential diagnosis of the nature of the cancer process. The level of zinc in post massage urine did not show significant prognostic and differential diagnostic potential. Changes in the content of citrate, sarcosine and spermine in prostatic urine allow us to clearly predict not only the presence of PC, but also to make a differential diagnosis of cancer. Monoinositol showed only differential diagnostic potential in PC.