The advent of targeted prostate biopsies to suspicious lesions based on imaging confers improved detection of clinically significant prostate cancer. The oversampling of these lesions is likely to better represent the cancer grade. However, such grade inflation might lead to the Will Rogers phenomenon. This study aims to investigate whether patients with Gleason 3+4 cancer on transrectal biopsy are upgraded following transperineal MRI-targeted biopsy & whether this has implications for current clinical practice.
This retrospective analysis examined 107 consecutive patients presenting at a single tertiary referral centre (July/2012-July/2016) with prostate cancer of Gleason score 3+4 on transrectal ultrasound-guided systematic non-targeted TRUS-biopsy who then underwent a multi-parametric MRI followed by MRI-targeted transperineal prostate biopsy for accurate risk stratification and localization.
Mean (SD) age was 67.0 (8.0), median (IQR) PSA 6.2 (4.7-9.6) ng/ml. Eighty-four of 107 (78.5%) had Gleason 3+4 on both transrectal systematic biopsy and transperineal MRI-targeted biopsy. Nineteen (17.8%) were upgraded to Gleason 4+3, 3 (3.0%) to Gleason 4+4 and a single (1.0%) patient to Gleason 4+5. These differences were significant (p=0.0006). Likewise, 23/107 (22%) of patients had higher risk disease based on their targeted biopsies.
The use of targeted biopsy in men with impalpable cancer, ultimately upgrades 1 in 5 men from favourable intermediate to unfavourable intermediate risk disease or worse. This has significant clinical implications for men considering active surveillance or radical treatment. Our risk calculators must now be validated using these data from targeted biopsy as the technique becomes widely adopted. This article is protected by copyright. All rights reserved.
BJU international. 2019 May 13 [Epub ahead of print]
Edward J Bass, Clement Orczyk, Alistair Grey, Alex Freeman, Charles Jameson, Shonit Punwani, Navin Ramachandran, Clare Allen, Mark Emberton, Hashim U Ahmed
Division of Surgery and Interventional Science, University College London, London, UK., Department of Histopathology, University College London Hospitals NHS Foundation Trust, London, UK., Centre for Medical Imaging, Division of Medicine, University College London, London, UK., Division of Surgery, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, UK.