Aim: To establish whether extended transrectal (TR) and extended transperineal (TP) biopsies are equivalent in detecting prostate cancer.
Methods: Due to an elevated prostate-specific antigen (PSA) greater than 2.5 ng/mL or abnormal digital rectal examination findings, 783 men underwent a transrectal ultrasound-guided three-dimensional 26-core biopsy, a combination of TR 12-core and TP 14-core biopsies. Using recursive partitioning, the best combination of sampling sites that gave the highest cancer detection rate at a given number of biopsy cores was selected either with a TR or a TP approach. The cancer detection rate and characteristics of detected cancers were compared between the TP 14-core and the TR 12-core biopsies and between selected subset biopsy schemes.
Results: Prostate cancer was detected in 283 of the 783 men (36%). There was no statistical difference in cancer detection rate or in the characteristics of detected cancers between TP 14-core and TR 12-core biopsies. As far as the best combination of sampling sites was selected, there was no statistical difference in cancer detection rates or in the characteristics of detected cancers between the TP and the TR subset biopsy schemes up to 12 cores. TP and TR biopsies performed equally, regardless of a history of negative biopsy, a digital rectal examination finding, the PSA level or the prostate volume.
Conclusions: We demonstrated for the first time that extended TP biopsy is as effective as its TR counterpart in detecting cancer and the characteristics of detected cancers, as far as sampling sites are selected to maximize the cancer detection rate.