Effect of peripheral biopsies in maximising early prostate cancer detection in 8-, 10- or 12-core biopsy regimens

To assess the cancer detection rate per individual core biopsy in a 12-core protocol and develop an optimal biopsy regimen for detecting early prostate cancer.

The study included 445 new patients who had a 12-core transrectal ultrasonography (TRUS)-guided prostatic biopsy over a 40-month period. The 12- core biopsy protocol included parasagittal sextant and six peripheral biopsies. The cancer detection rate per individual core was evaluated to give an optimal biopsy protocol.

Prostate cancer was detected in 142 patients (31.9%). Parasagittal sextant biopsy would have failed to detect 40 (28.2%) of the cancers. Among the various possible biopsy protocols, the optimum 10-core biopsy strategy excluding the parasagittal mid-zone biopsies from the 12-core protocol achieved a cancer detection rate of 98.6%.

The cancer detection rate increased from 71.8% for parasagittal sextant biopsies to 88.7% by adding peripheral basal biopsies (8-biopsy protocol); 98.6% of cancers in the series would have been detected with a 10-biopsy strategy omitting the parasagittal mid-zone biopsies. Thus we recommend a 10-core protocol incorporating six peripheral biopsies in patients with elevated age- specific prostate-specific antigen levels (2.6-10.0 ng/mL) for maximising cancer detection.