Immunohistochemical Study of Tumor Cells Proliferative Activity at Different Graduations of Prostate Cancer

Prostate cancer is one of the leading causes of men death in developed countries. Modern diagnostic methods, including a puncture biopsy of the prostate gland, make it possible to verify oncology in the early stages, however, routine studies do not always allow to predict the course of the disease and outcome. The aim of our study was to analyze the clinical, morphological and immunohistochemical features of the proliferative activity of adenocarcinoma cells using the Ki-67 marker, to compare the degree of proliferative activity in tumors of various degrees of malignancy (according to Gleason’s classification), as well as to compare this indicator with the clinical stage of the disease, the level of prostate-specific antigen in the blood, the size of the prostate gland. Materials and Methods: On the basis of the City Clinical Hospital No. 31 and the Veteran Hospital No. 2, paraffin blocks with material obtained as a result of prostate biopsy, transurethral resection, and radical prostatectomy were selected. A morphological and immunohistochemical study of the material with the Ki-67 marker and a quantitative assessment of the degree of proliferative activity were carried out. Data were analyzed using the STATISTICA 10.0 program using estimates of the normality of the data distribution according to the Shapiro-Wilk W-test, the significance of differences was estimated using the Mann-Whitney U-test, and correlation relationships using Spearman’s correlation coefficient. Results: Statistically significant differences in the degree of proliferative activity in groups differing in the degree of differentiation were revealed. A statistically significant direct correlation of moderate severity was revealed when comparing proliferative activity with the degree of differentiation according to the Gleason system (rs = 0.523) and the clinical stage of the disease (rs = 0.646). No statistically significant correlation was found between indicators such as prostate-specific antigen level, age, prostate volume, and proliferative activity index. Conclusion: taking into account the proliferative activity index in addition to clinical and morphological studies helps to diagnose and subsequently predict the course of prostate cancer.