Can biopsy be a reliable predictor of spatial distribution of prostate cancer? Comparison of a novel biopsy regimen with radical prostatectomy findings

Objectives: To obtain accurate spatial information on cancer distribution with a novel prostate biopsy regimen. Methods: From 2003 to 2005, 265 patients underwent a three fan-shaped biopsy (3FSB) technique of 12 to 14 cores and sextant biopsy (SB) simultaneously. When both techniques had positive findings, and radical prostatectomy was performed, the concordance among the positive biopsy locations of the SB, 3FSB, and the combination of both (the reference standard biopsy [RSB]), the proven locations of cancer, and the presence of extracapsular extension and positive surgical margins was calculated. Results: A total of 41 patients were selected, and 74 locations (left and right apex, left and right lobe) had cancer. Of these, 61 were confirmed by RSB, 58 by 3FSB, and 43 by SB with a sensitivity of 95%, 78%, and 58%, respectively. The sensitivity at the apical location was consistently greater for the 3FSB at 68% (19 of 28) compared with 40% (11 of 28) for all proven apical positive localizations and 100% (19 of 19) compared with 58% (11 of 19) for the RSB. The receiver operating characteristic analysis showed 78% accuracy for 3FSB and 68% accuracy for SB compared with the RSB. At the apex, the 3FSB and SB revealed positive surgical margins with a sensitivity of 1 and 0.4, specificity of 0.067 and 0.4, positive predictive value of 0.263 and 0.182, and negative predictive value of 1 and 0.667, respectively. Conclusions: The 3FSB had a great ability to find cancer in the gland, especially at the apex.