Worldwide comparison of prostate needle biopsy quality in the reduction by dutasteride of prostate cancer events (REDUCE) study: Improvement with investigator training

Abstract

e16029 Background: The accuracy of prostate cancer detection by biopsy is influenced by the number and length of needle biopsy cores. We compared these two biopsy quality factors among study sites worldwide for the pre-study entry biopsies (6–12 cores) and study-mandated biopsies (10 cores) at year 2 of the REDUCE study. Methods: Prostate biopsy quality indicators were evaluated retrospectively. Data were compared from entry and year 2 biopsies for subjects enrolled in the study in 6 geographic regions (see table ). Investigator training was provided for REDUCE study protocol-required standardization prior to year 2 biopsies. Training included emphasis on quality of the biopsies. Results: Data were collected from 4638 entry and 6275 year 2 subjects, respectively. At entry, the aggregate length of biopsies, number of cores per subject, and core length differed significantly among regions (p < 0.0001). Aggregate length was longest in biopsies obtained in Australia and the highest core number was observed in South America. At year 2, each region collected a mean of 10 cores per subject (per protocol), and the aggregate length and mean core length were greater than the entry biopsies (for each analyzed parameter, p < 0.0001); variance among sites was reduced for all quality measures. Conclusions: There were significant differences in biopsy quality (number of cores and length of tissue obtained) around the world at entry. Following the REDUCE study protocol-required standardization and investigator training, biopsies obtained at year 2 showed an increase in the mean aggregate length, mean core number, and mean core length compared with the entry biopsies. Our data suggests that variance in biopsy quality may be reduced by investigator training, thereby optimizing quality and cancer detection. [Table: see text] [Table: see text]