gms | German Medical Science

Introduction: Gleason score upgrading between prostate biopsy and radical prostatectomy specimen is a well-known phenomenon. As new therapeutic options like active surveillance or focal therapy for low risk PCa are getting more popular in the last years, the accurate identification of the Gleason score in the pre-therapeutic prostate biopsy is gaining more importance. In this study, we evaluated if MRI/ultrasound fusion based targeted biopsy leads to a reduced rate of Gleason score upgrading compared to post prostatectomy specimen.

Materials and methods: The histopathological findings of the biopsy of the prostate and the radical prostatectomy (RP) specimen of 210 patients who were referred to our hospital between 2012 and 2017 were compared retrospectively in this study. 105 patients who underwent MRI-ultrasound fusion based targeted biopsy were matched with 105 patients who underwent transrectal ultrasound guided 12-core biopsy of the prostate solely. We evaluated the rate of up- or downgrading in the prostatectomy specimen in both groups, the MRI based biopsy and the random biopsy and compared the results performing a matched pair analysis.

Results: In the two groups, changes in Gleason grade between biopsy and RP specimen occurred in 53.3 % (MRI/ultrasound fusion based targeted biopsy) and 50.5 % (random biopsy, p=0.045). The rate of downgrading was statistically significant (p=0.014) and was higher in the target biopsy (14/105 patients, 13.3 %) than in the random biopsy (4/105 patients, 3.8 %) group. A higher rate of upgrading was seen in the random biopsy group (49/105 patients; 46.7 %) compared to the target biopsy group (42/105 patients; 40 %) with no statistical significance (p=0.331). Concordance in Gleason score was found in 52/105 patients (49.5 %) in the random biopsy and in 49/105 patients (46.7 %) with MRI/ultrasound fusion (p=0.679). The change in Gleason score from biopsy to final pathology in patients with Gleason 6 or 7a at biopsy level was not statistically significant (p = 0.168).

Conclusion: MRI/ultrasound fusion-based targeted biopsy does not decrease the rate of upgrading between biopsy and final pathology in radical prostatectomy specimen.