This was a 57-year-old male with lower urinary tract symptoms, PSA of 6.7 ng/mL (1.8 ng/mL two years prior), no family history of prostate cancer and a negative DRE. Dr. Scattoni notes at this point that currently there is no role for antibiotic treatment in these individuals, and is not recommended by current guidelines. Based on the NCCN guidelines, a reasonable next step is to repeat a PSA or proceed to with a TRUS biopsy, which should include an extended pattern (12 cores), including sampling of the lateral peripheral zones and lesion-directed targets whether this is by digital palpation or suspicious imaging.
This gentleman was 71 years old with a PSA of 7.1 ng/mL with no family history and negative DRE. His transrectal ultrasound demonstrated a 110-gram prostate with a hyperechoic lesion on the right lobe. Dr. Scattoni then lead a discussion regarding the feasibility of ultrasound imaging, specifically highlighting the PROMIS trial , which showed that mpMRI was more accurate in terms of sensitivity (93% vs 48%) and NPV (89% vs 74%), while TRUS-biopsy was more accurate in terms of specificity (96% vs 41%) and PPV (90% vs 51%). Further analysis of this data has implications for the introduction of mpMRI as a triage test to the standard pathway of TRUS-biopsy: in the worst-case scenario, there would be a 5% decrease in over-diagnosis and similar diagnostic accuracy compared to TRUS-biopsy. In the best-case scenario, assuming similar MRI-directed TRUS-biopsy diagnostic accuracy as transperineal mapping biopsy, we would observe an increased rate of over-diagnosis of 5%, but an increased significant cancer detection rate of 18% compared to the standard TRUS-biopsy pathway. For both scenarios, 27% of men would avoid a primary biopsy.
This man was 58-years-of-age, with a PSA of 5.1 ng/mL and free-total ratio of 12%, a negative DRE, and a family history of prostate cancer. His initial 12-core biopsy showed one focus of HGPIN and subsequent PSA 8 months later was 8.4 ng/mL with a free-total ratio of 16%. His prostate volume was 40cc and an mpMRI showed a PIRADS 1-2 lesion. Dr. Scattoni notes that the EAU guidelines  recommend a repeat biopsy after a negative biopsy for: (i) rising and/or persistently elevated PSA, or (ii) suspicious DRE, or (iii) atypical small acinar proliferation, or (iv) extensive HGPIN, or (v) a few atypical glands immediately adjacent to HGPIN.
Dr. Emberton then started his part of the session by highlighting that the elements that determine detection rate for clinically significant prostate cancer include the PIRADS score and number of positive cores to the target. Furthermore, in a study from his institution, Dr. Emberton notes that transperineal MRI targeted biopsy detects the same level of clinically significant, but statistically significant less clinically insignificant prostate cancer . Additionally, their group has also demonstrated that transperineal targeted biopsies are safe and feasible under local anesthesia, including a zero-sepsis rate and 1% urinary retention rate . Perhaps the greatest ringing endorsement for this approach is that 89% of the 181 patients would recommend this technique to a friend.
This patient had a PSA of 6.1 ng/mL, PSA density of 0.20, and no previous prostate biopsy. He underwent an mpMRI that demonstrated a PIRADS 5 lesion tight to the peripheral zone. For this case, Dr. Emberton planned a cognitive MRI-guided transperineal biopsy using anatomical fiducials. Dr. Emberton notes that by cognitively assessing the tumor location in relation to the urethra and transitional zone he is able to make multiple passes at different locations through the tumor, thus producing a quantitative representation of tumor pathology. A recent study  of 594 lesions from 482 men compared target MRI in-gantry to cognitive target transperineal or transrectal guided prostate biopsies with PIRADS 3-5 MRI lesions. Importantly, the authors found no significant difference in biopsy methods with regards to all prostate cancer detection and clinically significant prostate cancer. Identification of an abnormal lesion on mpMRI appears to be more important in increasing the detection of prostate cancer than the technique used to biopsy the MRI abnormality.
Speaker: Mark Emberton, University College London, London, UK; Vincenzo Scattoni, San Raffaele Scientific Institute, Milan, Italy
Written By: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre, Twitter: @zklaassen_md at the EAU - Update on Prostate Cancer – September 15-16, 2017– September 15-16, 2017 - Vienna, Austria
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