Number of positive systematic sextant biopsies predicts surgical margin status at radical prostatectomy

Objectives. To determine whether the number of positive sextant biopsies co ntributes to the prediction of positive surgical margins, as the value of s ystematic prostate biopsies in predicting margin status at radical prostate ctomy is unclear. Methods. Consecutive patients (n = 108) who underwent radical retropubic pr ostatectomy and systematic sextant biopsies were retrospectively evaluated. Serum prostate-specific antigen, digital rectal examination, primary Gleas on grade, Gleason score, and the number and location of positive sextant bi opsies were recorded for each patient. Radical prostatectomy specimens were evaluated by step-section techniques at 3 to 5-mm intervals. Univariate co m parisons for each of these variables was performed between the positive a nd negative margin groups using the Mann-Whitney U test or chi-square analy sis. Logistic regression analysis was performed for these variables. Results. Twenty-two (20.4%) of 108 patients had a positive surgical margin because of extension of the tumor through the capsule. Patients with three or more positive biopsies were at higher risk of having a positive surgical margin (P = 0.009). Patients with bilaterally positive biopsies at either the base or midprostate were more likely to have a positive surgical margin . The risk of a positive surgical margin was not significantly determined b y the primary Gleason grade, Gleason score, or prostate-specific antigen. M ultivariate logistic regression models were created that consistently demon strate that the number of positive biopsies was the best predictor of margi n status. Conclusions. This study demonstrated that the number of positive sextant bi opsies contributes to the prediction of margin status at radical prostatect omy. UROLOGY 54: 689-693, 1999. (C) 1999, Elsevier Science Inc.