Transperineal Prostate Biopsy Improves the Detection of Clinically Significant Prostate Cancer among Men on Active Surveillance

Abstract

Purpose: Transperineal prostate biopsy offers improved sampling of the anterior prostate compared to the transrectal approach. The objective of this study was to determine if transperineal prostate biopsy is associated with an increased incidence of cancer upgrading among men on active surveillance for very low or low risk prostate cancer.

Materials and methods: Our active surveillance registry was queried to identify patients who underwent a surveillance biopsy following the introduction of transperineal prostate biopsy at our institution. Patients were dichotomized by the type of biopsy performed. The baseline characteristics and rates of cancer upgrading were compared between groups.

Results: Between November 2017 and June 2020, 790 men with very low or low risk prostate cancer underwent a surveillance biopsy. In total, 59 of 279 men (21.2%) in the transperineal prostate biopsy group were upgraded to grade group ≥2 as compared to 75 of 511 (14.7%) in the transrectal biopsy group (p=0.01). Among patients who were upgraded to grade group ≥2, 26 of 59 (44%) had grade group ≥2 detected in the anterior/transition zone with transperineal prostate biopsy compared to 14 of 75 (18.7%) with transrectal biopsy (p=0.01). Additionally, 17 of 279 men (6.1%) who underwent transperineal prostate biopsy were upgraded to grade group ≥3 vs 17 of 511 (3.3%) who underwent transrectal biopsy (p=0.05). After adjusting for age, prostate specific antigen density, use of magnetic resonance imaging, and number of prior transrectal biopsies, transperineal prostate biopsy was significantly associated with upgrading to grade group ≥2 (OR 1.49, 95% CI 1.11-2.19, p=0.01).

Conclusions: Among men on active surveillance for very low or low risk prostate cancer, transperineal prostate biopsy was associated with an increased likelihood of upgrading to clinically significant prostate cancer. This is likely due to improved sampling of the anterior prostate with the transperineal approach.

Keywords: biopsy; prostate; prostatic neoplasms; watchful waiting.