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 >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) > or =7 at biopsy was 44.5% whereas, at RRP, it was 68.3%. The rate of upgrading from Gleason <7 at biopsy to GS > or =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 > or =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.