Prostate cancer detection rate of transrectal ultrasonography, digital rectal examination, and prostate-specific antigen: results of a five-year study of 6- versus 12-core transperineal prostate biopsy.

The purpose of the present comparative work was the processing and assessment of data collected in a five-year period of urological practice with more than 1.500 transperineal, ultrasound-guided, prostatic biopsies performed. Our aim was to identify advantages and limitations of 6 and 12-core protocols, by extending the evaluation not only to cancer detection rate but also to the other histological findings. A total of 1.151 patients were included in the study. Two subgroups were identified: 836 patients who had undergone a 6-core biopsy from 2001 to 2004, and 315 patients who had undergone a 12-core biopsy from 2005 to 2006. Cancer detection rate was 291/836 (34.8%) in group 1 (6-core biopsy), and 148/315 (47%) in group 2 (12-core biopsy) (P<0.0001). The total number of histological diagnoses other than cancer was 162/836 in group 1 (19.4%) and 103/315 (32.7%) in group 2 (P<0.0001). In prostate biopsy, a higher number of cores seems to definitely improve its diagnostic value by dramatically decreasing the number of negative findings. The 12-core technique is particularly effective in case of prostate-specific antigen (PSA) values ranging between 4.1 and 10 ng/mL combined with a free-to-total PSA ratio below 16%, in case of negative digital rectal examination and when serum prostate-specific antigen levels are lower than 4 ng/mL. On the other hand, in the case of abnormal digital rectal examination, especially when combined with high prostate-specific antigen levels and/or changes detected at transrectal ultrasound, the 6-core technique can be considered a reasonable strategy.