Three-dimensional combination of transrectal and transperineal biopsies for efficient detection of stage T1c prostate cancer

Abstract

Background: Although an increasing number of men present with stage T1c prostate cancer, the optimal biopsy strategy for detecting stage T1c disease still remains to be defined. The aim of this study was to explore an efficient first-time biopsy scheme for detecting stage T1c and T2 prostate cancer.

Methods: A transrectal ultrasound-guided systematic three-dimensional 26-core (3D26) biopsy comprising 12 transrectal and 14 transperineal sampling sites was performed in 321 men with median prostate-specific antigen (PSA) level of 6.0 ng/ml in the first-time biopsy setting. By analyzing site-specific cancer detection rates, we determined the best combination of transperineal and transrectal sampling sites.

Results: Prostate cancer was detected in 109 of the 321 men (34%) with a major complication rate of 0.6%. 3D26 biopsy significantly improved cancer detectability by 60% relative to the conventional transrectal sextant (TR6) biopsy. Improvement was significant in 263 men with normal digital rectal examination (DRE) (85%, P = 0.0004) but not in 58 men with abnormal DRE (22%, P = 0.18). The mean Gleason score of the 41 cancers without a positive core within the TR6 sites was marginally lower than that of 68 cancers with a positive core within the TR6 sites (P = 0.04). Recursive partitioning revealed that a three-dimensional 14-core (transrectal 8-core plus transperineal 6-core) and a three-dimensional 8-core (transrectal 4-core plus transperineal 4-core) biopsies could detect more than 95% of stage T1c and T2 cancers with a minimum number of cores, respectively.

Conclusion: We propose a three-dimensional 14-core and a three-dimensional 8-core biopsy as efficient first-time biopsy schemes to detect stage T1c and T2 prostate cancer, respectively.