Transperineal 12-core systematic biopsy in the detection of prostate cancer

Background: The present study was designed to determine the clinical value of transperineal 12-core systematic prostate biopsy guided by transrectal ultrasonography (TRUS) in the detection of prostate cancer. Methods: A total of 679 consecutive patients underwent systematic prostate biopsies because of abnormal results on digital rectal examination and/or TRUS and/or an elevated serum prostate-specific antigen level. Systematic six- and 12-core biopsies were taken in 138 patients between April 1994 and February 1995 and in the remaining 541 between March 1995 and February 2000, respectively. Twelve-core biopsy included two samples from the lateral portion of the peripheral zone and four from the anterior portion of the transition zone in addition to the conventional six-core biopsy. Results: In the series overall, systematic biopsy revealed 156 cases of prostate cancer (23.0%). The detection rate increased by 5.2%, although this was statistically not significant, from 18.8% (26/138) by six-core biopsy to 24.0% (130/541) by 12-core biopsy. Out of 130 patients in whom prostate cancer was detected by 12-core biopsy, it was supposed that conventional six-core biopsy would have missed 18 cases (13.8%). Conclusions: Systematic 12-core biopsy might improve the detection rate for prostate cancer. However, further studies are needed to determine its clinical value in the diagnosis of the disease.