Transperineal template prostate-mapping biopsies: an evaluation of different protocols in the detection of clinically significant prostate cancer
Menée à partir des données d'un registre médical portant sur 391 patients (âge : 58 à 67 ans), cette étude évalue la performance de trois stratégies de prélèvement pour détecter un cancer de la prostate cliniquement significatif (taille maximale de la tumeur ≥ 4 mm et/ou score de Gleason ≥ 3 + 4)
Objectives : To determine whether modified transperineal template prostate-mapping (TTPM) biopsy protocols, altering the template or the biopsy density, have sensitivity and negative predictive value (NPV) equal to full 5-mm TTPM.
Patients and Methods : Retrospective analysis of an institutional registry including treatment-naïve men undergoing 5-mm TTPM biopsy analysed in a 20-zone fashion. The value of three modified strategies was assessed by comparing the information provided by selected zones against full 5-mm TTPM. Strategy 1, did not consider the findings of anterior areas; strategies 2 and 3 simulated a reduced biopsy density by excluding intervening zones. A bootstrapping technique was used to calculate reliable estimates of sensitivity and NPV of these three strategies for the detection of clinically significant disease (maximum cancer core length ≥4 mm and/or Gleason score ≥3 + 4).
Results : In all, 391 men with a median (interquartile range, IQR) age of 62 (58–67) years were included. The median (IQR) PSA level and PSA density were 6.9 (4.8–10) ng/mL and 0.17 (IQR 0.12–0.25) ng/mL/mL, respectively. A median (IQR) of 6 (2–9) cores out of 48 (33–63) taken per man were positive for prostate cancer. No cancer was detected in 67 men (17%), whilst low-, intermediate- and high-risk disease was identified in 78 (20%), 80 (21%), and 166 (42%), respectively. Strategy 1, 2 and 3 had sensitivities of 78% [95% confidence interval (CI) 73–84%], 85% (95% CI 80–90%) and 84% (95% CI 79–89%), respectively. The NPVs of the three strategies were 73% (95% CI 67–80%), 80% (95% CI 74–86%) and 79% (95% CI 72–84%), respectively.
Conclusion : Altering the template or decreasing sampling density has a substantial negative impact on the ability of TTPM biopsy to exclude clinically significant disease. This should be considered when modified TTPM biopsy strategies are used to select men for tissue-preserving approaches, and when modified TTPM are used to validate new diagnostic tests.
BJU International , résumé, 2014