Missing the Mark: Prostate Cancer Upgrading by Systematic Biopsy over Magnetic Resonance Imaging/Transrectal Ultrasound Fusion Biopsy

Abstract

Purpose Multiparametric MRI (mpMRI) and fusion biopsy (FBx) detect more high-risk prostate cancer (PCa) and less low-risk PCa than systematic biopsy (SBx). However, there remains a small subset of patients where SBx captures higher grade disease than FBx. We aim to identify potential mechanisms for failure of FBx biopsy in detection of clinically significant (CS) PCa. Methods We reviewed a prospectively maintained database of patients undergoing mpMRI followed by FBx and SBx from 2007-2014. In patients disease upgraded to CS disease (Gleason ≥ 7) by SBx over FBx, independent re-review of MR imaging, archived biopsy imaging, and whole mount pathology, as well as needle coordinate mapping were conducted. Multivariate logistic regression analysis was performed to determine predictors for upgrading by SBx. Results Disease upgrading based on SBx over FBx occurred in 135/1003 (13.5%) patients, of which only 62 (6.2%) were to intermediate (Gleason=7) [N=51, 5.1%] or high risk PCa (Gleason≥8) [N=11, 1.1%]. On multivariate analysis, lower PSA (p <0.001), higher MRI prostate volume (p <0.001), and lower number of target cores (p=0.001) were predictors of upgrading by SBx. Main mechanisms for under-grading by FBx included mpMRI reader oversight, presence of MR invisible cancer, FBx technique error, and intra-lesion Gleason heterogeneity. Conclusions MRI and FBx rarely misses CS PCa, as only 62/1003 (6.2%) cases were upgraded to CS disease by SBx. Imaging and biopsy techniques are continually refined and further studies will help to clarify mechanisms of FBx failure and patient populations which benefit from SBx in addition to FBx.

Does the introduction of prostate multiparametric magnetic resonance imaging into the active surveillance protocol for localized prostate cancer improve patient re‐classification?

“…Repeat PB procedures are invasive, with a 1-3% risk of urosepsis via the transrectal route despite antibiotic prophylaxis [19,20]. Moreover, transrectal biopsies without prior mpMRI (which aids location of lesions such as those in the anterior prostate) [21][22][23][24][25][26][27][28][29] have the potential to inadequately sample the gland, and in keeping with this, between a third and a half of men have had disease upgrading at subsequent radical prostatectomy [30,31]. It is therefore possible that replacing PB with mpMRI AE TB where needed in the case of radiologically significant lesions could benefit men on AS programmes, as the introduction of mpMRI can help to minimize the invasive nature of monitoring for disease progression.…”

Accuracy of elastic fusion biopsy in daily practice: Results of a multicenter study of 2115 patients

“…1 The advent of mpMRItargeted biopsies has improved the CDR, usually estimated to be approximately 33%, and in particular the detection of clinically significant cancers. 7 However, to date, several challenges exist regarding the implementation of TRUS-mpMRI fusion biopsies in clinical practice: among these, the inaccurate reading of mpMRI, which should be restricted to dedicated radiologists; 5 the presence of approximately 10% of significant cancers invisible to mpMRI; 8 the inaccurate sampling of lesions during fusion biopsy, as a result of inaccurate segmentation of mpMRI images or registration; 9 and last, but not least, mechanical error of the device used. In contrast, TRUS-mpMRI fusion biopsies achieve good results with acceptable costs, good reproducibility and accessibility for the patient.…”

Prostate ultrasound: back in business!

“…Salami et al [54] showed that performing only MRI targeted biopsy in patients with highly suspicious lesions still misses 3.5% of clinically significant prostate cancers, and 6.2% of the patients that undergo fusion biopsy are upgraded to clinically significant disease at concurrent systematic biopsy [55].…”