Transrectal Extended Biopsy of the Prostate : Does Additional Biopsy Improve the Cancer Detection Rate?

Objective: To assess improvement in the prostate cancer detection rate employing a transrectal biopsy protocol including the transitional zone at our institute. Methods: Between December 2004 and November 2005, 86 men (consecutive cases) underwent transrectal systemic 10-core prostate biopsy. Six cores were obtained from the peripheral zone (PZ) and four from the transitional zone (TZ). The cancer detection rate of the 10-core biopsy was evaluated; subsequently, it was compared with that of the 6-core biopsy. Results: Prostate cancer was detected in 40 cases (46.5%) based on the 10-core biopsy and in 46 cases (38.9%) based on the 6-core biopsy. The extended biopsy revealed positive findings in 32 cases. Four of the 32 cases were positive in the TZ with contralateral PZ involvement, whereas four cases were positive in the TZ, but negative in the PZ. Extended biopsy led to improved cancer detection (4/40= 10.0%). Conclusions: The cancer detection rate of the transrectal extended 10-core prostate biopsy including four TZ core specimens improved by 10%. A larger study is necessary in order to establish the reliability of the 10-core biopsy.