Office based transrectal saturation biopsy improves prostate cancer detection compared to extended biopsy in the...

Multiple studies have shown significant prostate cancer detection for repeat biopsy. However, the best approach regarding core number and location remains controversial. Transrectal saturation biopsy is believed to increase cancer detection but to our knowledge no studies comparing it to 12 to 14-core extended biopsy have been published. We compared saturation and extended repeat biopsy protocols after initially negative biopsy.

A total of 1,056 men underwent prostate biopsy after initially negative biopsy. The extended biopsy group included 393 men with 12 to 14-core repeat biopsy. The saturation biopsy group included 663 men with 20 to 24-core repeat biopsy. We analyzed demographics and prostate cancer between the 2 groups. We compared prostate cancer detection in patients with previous atypical small acinar proliferation and/or high grade prostatic intraepithelial neoplasia as well as the risk of detecting clinically insignificant tumors.

Prostate cancer was detected in 315 of the 1,056 patients (29.8%). Saturation biopsy detected almost a third more cancers (32.7% vs 24.9%, p=0.0075). In patients with a benign initial biopsy saturation biopsy achieved significantly greater prostate cancer detection (33.3% vs 25.6%, p=0.027). For previous atypical small acinar proliferation and/or high grade prostatic intraepithelial neoplasia there was a trend toward higher prostate cancer detection rate in the saturation group but it did not attain statistical significance (31.2% vs 23.3%, p=0.13). Of 315 positive biopsies 119 (37.8%) revealed clinically insignificant cancer (40.1% vs 32.6%, p=0.2).

Compared to extended biopsy, office based saturation biopsy significantly increases cancer detection on repeat biopsy. The potential for increased detection of clinically insignificant cancer should be weighed against missing significant cases.