Editorial Comment: The Number of Cancer-Involved Regions in Patients With Prostate Cancer Diagnosed by Magnetic Resonance Imaging/Ultrasound-Guided Fusion Prostate Biopsy Is a New Tumor Metric Associated With Increased Risk of Adverse Pathology at Radical Prostatectomy

It was interesting to read this study analyzing the factors predicting “adverse pathology” findings after radical prostatectomy among MRI/US-guided fusion prostate biopsy diagnosed prostate cancers. The authors conclude that maximum core length and number of cancer involved regions could predict adverse pathological findings.1 Although with a small sample size, the fact that 41.2% had adverse pathological findings post prostatectomy in this study implies these adverse findings could remain undetected if they went on to have nonextirpative treatments! MRI-based fusion biopsies of the prostate are increasingly being done, especially in the setting of previous negative prostate biopsies. One needs to be wary of these factors when counselling patients with MRI fusion biopsy-positive prostate cancers regarding treatment decisions. The definition of “adverse pathology” post radical prostatectomy is by itself variable bringing about challenges in homogenous reporting of these important findings. This calls for future research and uniformity in the definitions across urology societies. Surprisingly, clinical stage, Gleason score, and PSA levels are not predictors of adverse findings in this study. The inclusion of only T2 clinical stage and PSA <20 could have been a factor why this was not evident in the study results. It is interesting to note that the same group published a paper on this topic and found MRI-guided prostate biopsies were associated with more concordance with prostatectomy histology, than TRUS-guided biopsies.2 Overall, these results although intriguing, need further validation in view of the small sample size and the single centered data. Another pitfall is the number of MRI biopsy involved regions/cores depends largely on the number of biopsy cores taken by the operator. Despite these pitfalls, with more and more MRI fusion biopsies and radical prostatectomies being performed, I believe this study opens new questions for future research on this niche topic.