Introduction.  Prostate cancer (PCa) is a common and relevant disease, especially in developed countries. Radical prostatectomy (RP) remains the gold standard for the treatment of localized PCa. However, research findings often show conflicting results regarding the potential dividends in patients that choose this option. A recent meta- analysis demonstrated that the greatest benefits were observed in the high-risk group of PCa patients. Therefore, the identification of this contingent of patients is highly relevant. 
Biomarkers remain promising in this context. In particular, PCA3, the use of which is actively discussed, taking into account the heterogeneity of the research results. In our opinion, this can be associated with the studies designs. Objectives. In this work, we tried to evaluate the relationship between the PCa patients urine PCA3 levels and the tumor dominant growth pattern (TDGP) according to the tumor zone origin (TZO) in the context of the postoperative ISUP class (ISUP-GG). Materials and methods. The inclusion criteria were the presence of results: urine PCA3, total PSA, prostate MRI, ISUP-GG. The study included 130 participants, that were divided into subgroups depending on the TZO and TDGP: aPCa (anterior), aPZ-PCa (anterior, peripheral zone) and pPZ-PCa (posterior, peripheral zone). Results. The zones of origin of tumors according to the division into subgroups determined on the basis of MRI were confirmed by the results of patho- histological conclusion.  A statistically significant difference between the study subgroups was observed only in PCA3 levels.  The PSA level was significantly different only between the aPZ-PCa and pPZ-PCa groups. Based on the results of Spearman's rank correlation analysis, a statistically significant positive relationship between the level of PCA3 and ISUP- GG was obtained in the pPZ-PCa group. Conclusions.  It is worth taking into account the TZO and TDGP of PCa when PCA3 urine levels is interpreted.