Introduction. Radical prostatectomy (RPE) is still regarded as the gold standard for treatment of localized prostate cancer (PC). At the same time, the idea of “active surveillance” of patients with PC is gaining its popularity during the last decade. The patients from this group are characterized by the following parameters: their estimated life expectancy is more than 10 years, cT1/2, their PSA level is less than 10ng/ml, their biopsy Gleason score is less than 7 and they have less than 2 positive biopsies.

Materials and methods. This study was based on the results of treatment and medical examination of 348 patients with PC, who received RPE at the urological department of A.I. Yevdokimov Moscow State University of Medicine and Dentistry from Dec. 2014 to Dec. 2015. Among them, a cohort of 25 patients was chosen, whose preoperative diagnostics indicated a unilateral/unifocal pattern of the lesion. All these patients were proposed to undergo “active surveillance” but they preferred surgery instead. To investigate the reliability of the prostate biopsy data, the latter was compared with the results of pathomorphological examination of the dissected specimens of the prostate.

Results. Unifocal/unilateral lesions of the prostate were, in fact, present in less than 8% of the patients, who have already been diagnosed with it by transrectal biopsy. In 19 patients (76%), their clinical stage was classified as T2c. One patient was diagnosed with an extraprostatic extension (stage T3a) and in three patients, invasion of the seminal vesicles was found (stage T3b). 32% of the patients had an increase in Gleason score.

Conclusions. Our data provides evidence that 12-core biopsy, which is now used as a standard for PC diagnostics, is not a sufficient instrument for diagnosing unifocal/unilateral lesions. Further studies aimed at improving the optimal algorithm for PC diagnostics are required to determine the stages of the disease more precisely. This is especially relevant to those patients who are expected to undergo “active surveillance”, “focal therapy” and any kinds of delayed treatment.

Authors declare lack of the possible conflicts of interests.