Transperineal biopsy enhances detection of clinically significant prostate cancer

Among men on active surveillance for prostate cancer, transperineal prostate biopsy (TP-Bx) improved detection of clinically significant prostate cancer compared with transrectal prostate biopsy (TR-Bx), according to a retrospective analysis published in the Journal of Urology.¹

In the study, there was a significant association between TP-Bx and upgrading to grade group ≥2 (odds ratio, 1.49; P = .01). This link was established after adjusting for age, use of magnetic resonance imaging, number of prior transrectal biopsies, and prostate specific antigen (PSA) density.

“In this analysis we found that among men on active surveillance for very low or low risk prostate cancer, TP-Bx was associated with a higher likelihood of upgrading to clinically significant prostate cancer. This is likely due to greater sampling of the anterior prostate, an area of the gland that has previously been shown to give rise to more aggressive prostate cancer clones. Additional study is needed to determine if active surveillance algorithms should be modified to include TP-Bx,” investigators from John Hopkins University wrote.

The study retrospectively reviewed data from The James Buchanan Brady Urological Institute and Department of Urology, John Hopkins University School of Medicine, active surveillance registry. Researchers at Johns Hopkins University queried the registry for a list of men with very low or low risk prostate cancer who received active surveillance prostate biopsy at the institution during the timeframe from November 2017 to June 2020. Among 790 men identified by the query, 35.3% (n = 279) had received TP-Bx and 64.7% (n = 511) had received TR-Bx.

Across the entire study population, the median patient age was 67 years (IQR, 62-71) and the median PSA density at baseline was 0.10 ng/ml/gm (IQR, 0.08-0.17). In the TP-Bx arm, the median number of prior TR-Bx biopsies was 2 (IQR, 1-2) compared with 1 (IQR, 0-2) in the TR-Bx arm. The median number of years on active surveillance was 3 (IQR, 2-5) versus 2 (IQR, 1-4), respectively. In both arms, the median number of cores sampled was 12. In the TP-Bx arm, 55% of patients had very low risk prostate cancer and 45% of patients had low risk prostate cancer. The corresponding rates were 52% and 48%, respectively, in the TR-Bx arm.

In the TP-Bx arm, 21.2% (59/279) of men were upgraded to grade group ≥2 compared with 14.7% (75/511) inthe TR-Bx arm. In the TP-Bx arm, 44% (26/59) of the patients upgraded to grade group ≥2 had their grade group ≥2 disease identified in the anterior/transition zone, compared with 18.7% (14/75) of men in the TR-Bx group (P = .01). Further, the percentage of patients upgraded to grade group ≥3 was also higher with TP-Bx, at 6.1% versus 3.3% with TR-Bx (P = .05).

“The authors should be commended for considering an alternative approach to confirmatory prostate biopsy to minimize under-sampling of high grade disease, particularly of the anterior prostate, while also lowering the risk of infectious complications,” Robert Abouassaly, MD,

Glickman Urological and Kidney Institute, Louis Stokes Cleveland VA Medical Center, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, wrote in an accompanying editorial comment.²

“One needs to consider whether to apply this approach universally to all patients on active surveillance, or perhaps to select patients with certain clinical findings (anterior lesions on MRI, larger prostates, etc). Unfortunately, the answer to this important question would require a prospective randomized trial,” added Abouassaly.

References

1. Meyer AR, Mamawala M, Winoker JS, et al. Transperineal prostate biopsy improves the detection of clinically significant prostate cancer among men on active surveillance. J Urol. 2021;205(4):1069-1074. doi: 10.1097/JU.0000000000001523

2. Abouassaly R. Editorial Comment. J Urol. 2021;205(4):1074. doi: 10.1097/JU.0000000000001523.01