Indications for saturation biopsies of the prostate: Where do we stand?

Introduction & Objectives: Recent results of the European Prostate Cancer Detection study (EPCDS) and the 3 dimensional reconstruction of cancers detected on first and repeat biopsy suggested that cancers detected on repeat biopsy were located in more dorso-lateral (para-rectal) and apical location. The Vienna nomograms further identified the optimal number of cores required. The purpose of this study was to evaluate the value and legacy of saturation biopsies (22 cores) versus a novel modified biopsy protocol. Material & Methods: A total of 593 patients were evaluated in 8 European University centers. 212 patients with a total PSA (2.5-10 ng/mL) and an initial negative biopsy underwent a repeat saturation biopsy. A second group of 382 consecutive patients underwent repeat biopsy with a novel modified biopsy protocol using the Vienna nomograms and aiming at the apical and dorso-lateral regions. Uniand multivariate statistical analysis using the SAS system (CARY, North Carolina) and ROC curves were performed to compare cancer detection rates and distribution. Results: Cancer detection rate on first biopsy was 28.7%. Cancer detection rate on saturation repeat biopsy was 22.8%. Using the novel biopsy protocol, cancer detection rate upon repeat biopsy was 18.7%. As compared to patients diagnosed with PCa after the first set of biopsies, patients diagnosed after the second set had larger total prostate (tot vol.) and transition zone volumes (TZ vol.) (45.2 ± 11.0cc vs 33.7 ± 9.6cc, p = 0.0001 and 22.0 ± 6.5cc vs. 11.8 ± 8.3cc, p = 0.0001). These findings were identical to cancers detected on first and repeat biopsy with the saturation and modified protocol (p = 0.33). Morbidity of both the saturation and modified protocol biopsies were identical (p = 0.12), however significantly higher than with the standard octant biopsy protocol (p = 0.003). Using the cumulative logistic plot analysis the probability of a positive first/repeat biopsy core was analyzed. The dorsolateral biopsy cores (p = 0.001), followed by the apical (p = 0.02) and transition zone biopsy cores (p = 0.04) were the most common sites of cancer on repeat biopsy. On multivariate analysis, patients with HG-PIN on first biopsy, PSA > 8 ng/mL, tot vol. >50 cc, TZ vol 20-40cc, TZ/PZ ratio < 0.4 and a negative prior history of biopsies had a significantly higher detection rate on saturation biopsy. Conclusions: Saturation biopsy and modified biopsy protocols using volume/age charts resulted in a 69-78% improvement of the cancer detection rate on repeat biopsy as compared to standard repeat biopsies technique. However, saturation biopsies were not necessary in all patients with negative initial biopsies. Saturation biopsies were beneficial in patients with HG-PIN on first biopsy, PSA > 8 ng/mL, tot Vol >50 cc, TZ vol 20-40cc, TZ/PZ ratio < 0.4 and a negative prior history of biopsies resulting in a further 37% increase in detection rates.