Bladder neck-sparing modification of radical prostatectomy adversely affects surgical margins in pathologic T3a prostate cancer

Objectives. To determine whether the bladder neck-sparing (BNS) modificatio n of radical retropubic prostatectomy (RRP) alters the likelihood of positi ve surgical margins and postsurgical prostate cancer recurrence. Methods. Surgical outcomes, as measured by pathologic margin status and pro gression-free survival, were evaluated in 751 consecutive RRP cases, among whom 222 underwent BNS technique. To reduce selection bias, comparison of p ositive margin rates between BNS and standard RRP was stratified by patholo gic stage. Differences in surgical margin rates were assessed using the chi -square test, and effects of bladder neck preservation on prostate-specific antigen (PSA)-free survival were assessed, using multivariable Cox proport ional hazards analysis. Results. The clinical stage, Gleason score, and preoperative serum PSA prof iles were similarly distributed between patients undergoing standard RRP an d those undergoing the BNS modification. Surgical margins in the unstratifi ed entire cohort were positive at rates similar to prior reports (28% BNS, 27% standard RRP). However, stratification by pathologic stage revealed tha t among pT3a cancers, BNS surgery was associated with significantly higher rates of positive surgical margins than was standard RRP (47% versus 20%; c hi-square = 6.32, P = 0.01). Differences in positive margin rates were not seen between the two groups at other pathologic stages. The adverse effect of BNS technique on pT3a surgical margins was associated with a trend towar d an adverse effect on PSA-free survival (Cox proportional hazards P = 0.01 6). Conclusions. The BNS modification of RRP can be associated with an increase d rate of positive surgical margins specifically in cancers that have focal ly penetrated through the prostatic capsule (pT3a), with an associated tren d toward decreased PSA-free survival in this group. BNS surgery may, theref ore, compromise the ability to completely remove a subset of cancers focall y penetrating the prostatic capsule. UROLOGY 55: 904-908, 2000. (C) 2000, E lsevier Science Inc.