Difference of cancer core distribution between first and repeat biopsy: In patients diagnosed by extensive transperineal ultrasound guided template prostate biopsy.

Background: We performed extensive transperineal ultrasound guided template prostate biopsy and evaluated cancer core distribution.

Methods: From August 2000 to May 2002, 113 men with prostate specific antigen levels between 4.0 and 10.0 ng/ml underwent template biopsy. Eighty-six had no previous biopsy (first group) and 27 had previous transrectal sextant biopsies (repeat group). A mean of 18.4 biopsy cores were taken. We defined the region over 2 cm from the rectal face of the prostate as the anterior region and the other as the posterior.

Results: Cancer was detected in 49 of 113 (43%) men. Forty-two were in the first group and seven in the repeat group. In the first group, the cancer core rate (cancer core number/biopsy core number) in the anterior region (7.0%) had no difference from that in the posterior region (8.6%) (P = 0.7111). But in the repeat group, the cancer core rate in the anterior region (4.6%) was higher than in the posterior (1.5%) (P < 0.0001).

Conclusions: These results suggest that transrectal sextant biopsies miss more cancers in the anterior region than in the posterior. We believe template technique has an advantage to be able to detect cancer equally in the anterior and posterior.