A comparison of extended biopsy and sextant biopsy schemes for predicting the pathological stage of prostate cancer

Purpose: We compared the performance of the extended multisite directed biopsy strategy to the sextant component of this strategy for predicting the pathological stage and Gleason score of the radical prostatectomy specimen. Materials and Methods: We studied 157 men in whom prostate cancer was diagnosed by extended multisite directed biopsy and who underwent radical retropubic prostatectomy. The pretreatment variables of serum prostate specific antigen, prostate specific antigen density, biopsy specimen Gleason score, the location, number and percent of cancer containing cores, greatest tumor length in a single core and greatest percent of tumor in a single core were determined and compared with the pathological features of prostate cancer in the radical prostatectomy specimens. A comparison of the information obtained from sextant component cores of the extended biopsy strategy with that from all cores of the extended biopsy strategy was performed using chi-square statistics and ROC curve analysis. Results: When comparing the areas under the ROC curves, the extended multisite directed biopsy strategy was found to have greater predictive power for extraprostatic extension than the sextant core component of this biopsy scheme, although the difference was not significantly different. The sextant component was equivalent to the extended biopsy strategy for predicting the prostatectomy specimen Gleason score. Conclusions: The extended biopsy strategy has better performance in the upper sensitivity ranges compared to the sextant technique for predicting extraprostatic extension.