Biopsy-derived gleason artifact and prostate volume: Experience using ten samples in larger prostates

Purpose: To verify whether a significant relationship between the risk of Gleason upgrading and the prostate volume remains when the number of biopsies is increased for larger prostate volumes. Materials: A total of 281 biopsy-proven prostate adenocarcinoma cases who underwent radical prostatectomy ( RRP) formed the cohort for this study. Change in transrectal ultrasound of the prostate ( TRUS) biopsies number based on total gland volume was made simply by increasing the number of biopsies from 6 to 10 when prostate volume was 1 50 cc. The total number of cancers with Gleason pattern 4 or greater on biopsy and on RRP was tabulated over TRUS volume categories and tests for trend. Results: The proportion of Gleason score ( GS) 6 7 at biopsy was 44.5% whereas, at RRP, it was 68.3%. The rate of upgrading from Gleason <7 at biopsy to GS >= 7 at RRP was 46.8%. No significant difference in terms of age, serum PSA, prostate volume and pT stage was found between not upgraded and upgraded cases (p > 0.05). As prostate volume categories increase, the number of cancers upgraded at RRP slightly increases in particular from prostate volume 30 - 39 to 40 - 49 cc ( where only 6 biopsies were performed). However, either at biopsy or at RRP, the percentage of GS 6 7 tumors does not show a significant trend in changing (p > 0.05). Conclusions: We verified that the relationship between the risk of Gleason upgrading and prostate volume does not become significant simply by increasing the number of laterally directed biopsies from 6 to 10. Copyright (C) 2008 S. Karger AG, Basel.