Prostate Needle Biopsy Quality in Reduction by Dutasteride of Prostate Cancer Events Study: Worldwide Comparison of Improvement With Investigator Training and Centralized Laboratory Processing

Abstract

To compare biopsy quality factors among study sites worldwide at entry and at year 2 in the reduction by dutasteride of prostate cancer events study. The accuracy of prostate cancer detection is influenced by the length and number of biopsy cores. Biopsy quality factors at entry and at year 2 were compared for subjects enrolled from 6 geographic regions: North America, South America, Western Europe, Central/Eastern Europe, Australia, and Africa. Investigator training was provided for prostate biopsy collection before year 2, emphasizing core length and number of cores obtained. Data were collected prospectively from 4649 subjects at entry and 6267 subjects at year 2. At entry, the aggregate length, number of cores, and mean length of cores differed significantly among regions. Aggregate length was longest in biopsies from Australia, and number of cores was highest from South America. At year 2, each region collected the protocol-required 10 cores, and aggregate length and mean length of cores were greater than for entry biopsies; site variance was reduced for all factors. There were significant differences in aggregate length, number of cores, and mean length of cores among regions at study entry. After investigator training by the study sponsor and use of a central laboratory for standardized processing, year 2 biopsies showed an increase in all 3 quality factors when compared with entry biopsies. Variance in biopsy quality can be reduced by investigator training and standardization of collection and processing, thereby optimizing detection of cancer. Biopsy quality may be a useful comparative measure in urologic practice.